Sweet spots – Why your f/1.8 isn’t so great at f/1.8

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This may hit some beginners like a ton of bricks so brace yourself for a mild disappointment here: your lens isn’t wonderful at all f/stops. Yup. A Canon nifty fifty which opens to f/1.8 isn’t at its best when it’s wide open. And by ‘best’, I mean when a lens it at its sharpest. You see, there’s something known as a lens’ ‘sweet spot’ which is the aperture at which it’s at the sharpest and sometimes will even offer other things like better clarity.

It’s hard to give a blanket statement about the exact sweet spot for each lens because when you look up the chatter on the internet, there are such varying statements about, say, the sweet spot for the aforementioned Canon 50mm f/1.8. Some say it’s f/2.2 while others claim that the sweet spot is f/4. A good rule of thumb is that a lens starts moving more towards perfection about two stops above its maximum aperture. So where an f/1.8 can open all the way to f/1.8, you don’t actually want to shoot at f/1.8 if you want optimal sharpness and clarity. Try moving up a couple stops to f/2.2 or f/2.8 and compare the results you achieve.

While you can get info on the internet about your favorite lens’ sweet spot, the best thing you can do is set up a scenario and take a shot at all different apertures. You can do this by setting your camera on AV (or A on a Nikon) which is aperture priority mode. This means you will be able to change only the aperture and the camera will take care of all the other settings for you while you carry out your test. I would recommend using a tripod to eliminate factors that can alter sharpness like camera shake. After taking the photos, look at the images at 100% in your computer and you’ll notice some are sharper than others. Note the apertures used for those shots and you’ll know where to stay when shooting with that lens from then on.

I can hear you thinking: so I just spent over $1k on an f/1.2 and I can’t actually use my lens at f/1.2? I feel your pain – I’ve already gone through that grieving process myself! When talking about 50mm lenses, you could say that…

  • the max aperture on a f/1.8 is f/2.2
  • while the max aperture on an f/1.4 is f/1.8
  • and on a f/1.2, it’s going to be f/1.6

So you see, you’re still getting wider apertures, just not as wide as you may have first thought. But don’t let this sweet-spot-business discourage you from experimenting with and employing all sorts of wonderful wide-open apertures. It’s just important to understand how your gear works and how to get the best out of it.

So how about you – please comment below and share with us your sweet spots!

Read more from our Tips & Tutorials category

Elizabeth Halford is a Hampshire Photographer and keeps a rockin' photography blog where she writes about photography and business in "real.plain.english".

  • Kirk Billingsley

    Agreed

  • andrew

    a lens not sharp wide open is useless to me

  • Abbig Effenkuhnt

    I’ve got a 55 Nikon f/1.2 that I use with my Mark II in special situations. Depth of field is about 9 inches, so I end up shooting a lot either side of my focus and finding my winners in the post when shooting bands. Night landscapes are easy, it does infinity pretty well. There is a HUGE difference in sharpness moving up to f/2.8 with it. I also just adapted a G.Zuiko f/1.4 from an old OM-2 and it is far better on DOF but softer in contrast than the Nikon. It seems to be the same on moving up to f/2.8, just better results overall. Image is G.Zuiko:

  • Growing Faithphotography

    ok

  • Manuel Fernando Herrera Pinale

    Same here. The first photoshoot i did with my yongnuo 50mm was soft compared with 2 photos i took with my 55-250mm. I wish i knew this before that photoshoot. Cheap primes are pretty much useles wide open por stills. For video i wouldn’t mind going wide open.

  • 88?

    Question. Im fairly new to photography. If for instance my 50 canom 1.8 is sharpest at 2.8 does this also apply to long exposures landscapes and portraits ? I always thought when shooting landscapes and long exposures that having my f stop lower ie 13 and higher would get my overall composition as sharp as possible and when shooting portraits having my f stop more open is the way to go. Thank you in advance.

  • Terri Valkyrie

    Somewhere between f/3.5 and f/4 for the 50mm f/1.8 (not the newest revision) is the sweet spot for me.

  • Terri Valkyrie

    There is missing information when talking about shooting wide open without discussing distance from your subject. When you’re shooting a face shot close in with a 50mm, focusing on the eye, you’re going to get the eye in focus, maybe not even the whole eye in focus and quite likely not both eyes unless you’re exactly square to them and their eyes are on exactly the same plane. If you’re shooting someone from head to foot and framing that, you’re standing back a lot farther and thus, you should have your entire subject in focus, maybe, but at least their features are going to all be clear even if the back parts of their head/hair are starting to blur.

    This is something that becomes crystal clear to someone as soon as they obtain a macro lens and try to shoot wide open, you have a razor thin area of focus because you’re so close to your subject, which is obviously not desirable – however I’ve taken portraits with my macro lens (90mm) wide open and my subject is perfectly in focus with wild bokeh behind them.

    So, when talking about what aperture to use in terms of focus, it is entirely dependent on how far away you are from your subject. However, lenses do have “sweet spots” where they are sharpest, but they’re only going to be sharp within that focal area. Head shots at 2.8 are still not going to be ideal, unless having much of the head blurry is what you’re after.

  • Terri Valkyrie

    I want to say that you should ignore everything you’ve ever heard about sweet spots because you have to take the whole picture into account (pun!)

    The closer you get to your subject, the shorter the area of focus is going to be. When shooting with a macro lens wide open, that area is going to be razor thin, when shooting a head shot with a 50mm (on an APS-C anyway, it may be better on a FF sensor) you’re not going to get all the features and the entire head in focus. If you back away more, wide open, you should get most of your subject in focus.

    Instead of worrying about the sweet spot in a lens, worry about what the right aperture is for the shot that you want. The entire exposure matters as well, obviously, because you want a well-exposed image (or you don’t, in which case you want to purposely try to over or under-expose).

    If the sweet spot for a 50mm is f/2.8 (and with mine, I find f/3.5 or f/4 does best for me, I’ll post an example) then you still will need to be far enough away from your subject to have them existing in that area of focus. So, in short it does not apply to everything. However, if you want to shoot a landscape with a 50mm, then sure, set it to the sweet spot and adjust the rest of your exposure around it, you will probably get the results you want – for portraits though, it’s only going to work if you’re back far enough to get your entire subject in the focal area, which would probably be a whole body portrait.

    50mm f/1.8 lens on an APS-C camera – at f/3.5 at about 2.5′ from my subject. You can see that what is closest to the camera and farthest away is blurry, but the whole baby is in focus. At f/1.8 (or even f/2.8) there is going to be a lot less of him in focus.

  • Terri Valkyrie

    This is one that was shot wide open with the same lens at much closer range, though. I’m not sure what this site is doing to my colour, because it doesn’t look like that on my screen or on other sites that I’ve posted these images.

    Only part of his face is in focus as you can see.

  • Will Davis

    I just look at sweet spots as ‘starting points’. For example on my Nikkor 35mm 1:1.8 I know that, basically the first ‘big’ step up in sharpness happens at f/2.8. I use it as a starting point. If I need more DoF I’ll change it as appropriate. Sharpness on my lens doesn’t start to drop off sharply until beyond F11. I won’t go below f/2.8 unless I absolutely need to in order to achieve exposure.

    Nobody should be taking this sweet spot thing as a “you simply MUST shoot at these apertures at all times” kind of thing.

  • Thalis Valle

    the 50mm 1.8 II is only good from f2.8 to f8.0. All out of this is not good.

  • Thalis Valle

    No. For landscapes and photography with long dof you need to use f8.0. This is the maximum quality. Avoid f11

  • 3hunnit thousand $ ?

    thanks bud

Some Older Comments

  • 4orty 9ine March 31, 2012 06:45 am

    Here's a lens sharpness guide that loads into your camera and displays your lens's sweet spots on the camera's display screen: www.http://slrlensguides.com

  • Ibrahim Ahmed November 26, 2011 06:17 pm

    For me, sweet spot is when the depth of field created with my lens is helping the shot itself. So if I am shottting a portrait, and I want the face to be totally focused, (or the eyes only sometimes), so in order to do this I have the set the DOF to the optimum setting to take the required shot. And the depth of field is not as you know determined only by the aperture but also with, "Focus Distance" and the lens "Focal Length". So I wouldn't dare trying to shot a portrait with 85mm 1.2 from 2 meter distance and complain about soft portrait and get disappointed with the $2K lens.

  • Ibrahim Ahmed November 26, 2011 06:08 pm

    The sweet spot of a lens (i.e. sharpness) is not determined mainly by the aperture, but also by the distance of the focus object. Do not try to take a shot in largest aperture and 1 meter distance focus and yet complain about the sharpness because your DOF will be 3mm at these settings and most probably only the tip of your subject nose will be in focus. So it's a combination of aperture, focus distance and available light intensity.

  • Trevor Olner November 11, 2011 08:28 pm

    Digital cameras with the smaller sensors have always had a greater depth of field than full frame sensors. There is a optical reason for this.But the smaller sensors have also suffered from more noise because of the way the chip has been crammed with pixels.

    This page on wikipedia explains it better than I can

    http://en.wikipedia.org/wiki/Digital_camera#Image_sensors

  • paul November 11, 2011 09:59 am

    I agree with the two sides of the story on this article. Shooting at wide apertures can be very desirable, especially for portrait work. Some of my favorite portraits have been done with my Canon 85 1.8, which is not an expensive lens. I like that I can get the eyes in focus, and the rest of the face just soft enough at 1.8. Shooting wide open also allows photographers to simplify the background via creamy bokeh, and put the emphasis on the subject. Yet, if you want everything in focus, then you should be shooting at smaller apertures. This sweet spot can change from lens to lens, and within the same lens made by the same manufacturer. We have to remember that lenses are manufactured, and that there is error in this process so not all of the same lenses will be sharp at the same aperture. This is why camera bodies have come out with micro-adjustments so you can tweak your body for lenses that may not be as sharp as possible without this adjustment. Depth of field also changes between crop bodies and full frame bodies. I started out with a 40D, and when I went to the 5D mk I I was amazed how much shallower the depth of field was with the same lenses I used with my 40D. We have to learn to appreciate these variations, and decide what is best for the work that you shoot. The author of this article was obviously directing the article to new photographers. I think the author could have addressed some of the issues that I brought up to give newbies more of the whole picture. Having said that, some newbies would probably read my post and scratch their heads, so maybe the author was simplifying the issue to make it more understandable. A great discussion, and one that every photographer must deal with, new or seasoned.

  • Boudoir Photography October 26, 2011 02:11 am

    do what huh ???

  • Shannon October 5, 2011 08:55 am

    Elizabeth, thanks for another informative article. I have been wondering about the 'sweet spot' but when I read about it my mind starts to fuzz over and I give up. You made it very simple and to the point. Now I want to try my favorite lens on the tripod and go through the apertures to find where mine is sharpest at.

  • zos xavius September 28, 2011 06:53 am

    Why would you possibly desire a 1.2 if you never use it wide open? In low light that extra stop is huge and if you are doing street or portait, extremely useful at getting a nice reasonably sharp shot with frozen motion. Sure its gonna be soft. A soft shot is better than none. A faster lens is always far more useful than a slow one. You wanna teach people about aperture? Tell them to run in Av primarily and to use aperture to gather light and reduce dof. If sharpness is of the most importance, you would be using a tripod and sitting in the sweet spot or like f4-5 preferably....probably more so you can have some dof.

  • Mark Schafer September 27, 2011 10:42 pm

    While you are generally right with your observation, please consider the correct f stops, your examples only close 2/3 down not 2 full stops, aka a f1.4 should be at f2.8. My personal philosophy is to test it out, but I feel most lenses Perron best on the opposite side of the scale, 2 stops below highest f stop, aka if the lens closes to f45 is at it's sharpest around f22. It might not be that easy to detect due to the increased depth of field but is true for most large format lenses.

  • Sâmela September 26, 2011 12:10 am

    Sure, but that doen't mean you won't make beautiful, sharp images wide open. Like this image for instance http://www.facebook.com/photo.php?fbid=285751141439721&set=a.285750978106404.84723.283995514948617&type=1&theater it was taken with my 50mm nikon 1.8G at 1.8
    Its a sweet sweet image IMHO

  • Trevor Olner September 25, 2011 07:51 pm

    Any self respecting photographer should know that any lens at is widest aperture isn't at its best. That said
    the reason for wider apertures is so photographers can have better results in low light conditions even when they stop down two f stops. The problem of shooting in low light conditions is more applicable to film cameras when the ISO is fixed by the film speed . Uprating a film from its intended ISO is always fraught with complications with pushing film development. Colour neg film is probably the worst as there is always a colour shift and alteration in contrast that cannot always be corrected by filtration at the printing stage.
    Digital cameras have come along way in higher ISO settings as camera manufactures have been dealing with the noise problems with chip manufacture and in camera software. The trade of with high ISO's with film is a larger grain pattern which some photographers like.

  • JP September 25, 2011 10:45 am

    Thanks for posting this information. Regardless of what anyone else is saying here and how critical people are being, I get what you're saying...to test your camera at different apertures/settings to explore and figure out what you like best about your camera before thinking that something is 'not right'. I think it's very useful for you to post reminders like this, especially for those of us that havent been doing photography for as long as others. That's what this blog is for, right.

    Chill out people...if you have something to say, share your knowledge like a professional that others can respect, not like a critical jerk.

  • oldfox September 25, 2011 09:55 am

    Hey! I tried that pinch of salt that two of you recommended and it was so humid here today that the salt melted into a gooey paste that has gummed up my lens mount and focus ring something horrible! When I trip the shutter, the flapping, bouncing mirror is propelling the toxic muck into more and more critical mechanical structures.

    I think I am going to be sick.

    All kidding aside, perhaps this is a naive question from a newbie, but would a setting that provides a very lot of depth of field compensate for any miscalibration of the sweet spot? In other words does a too-wide f-stop merely look like poor focus which could be remedied with more depth of field (and more light if necessary)?

  • troodles September 23, 2011 06:44 pm

    elizabeth as a newbie i have to say i loved your article!!! thanks

  • Marko September 23, 2011 05:54 am

    I know it's old stuff, but nevertheless I look forward to tomorrow, about half an hour with the tripod and all the lenses I have. I will prepare a little xls with lenses, min and max apertures, and sweet spots for each!

  • Yung Chia September 21, 2011 10:13 pm

    @soon

    Thanks, Soon, for the links. Very good to know. Ahhh, there's so much to learn. I think digital cameras have come a long way and our knowledge of it's capacity, limitations, and strengths are still in its infancy as opposed to hundreds of years of non-digital SLRs and pinhole cameras. The key is to stay open-minded and experiment and take lots and lots of pictures. Thank you for sharing.

  • Soon September 21, 2011 05:25 pm

    @yungchia
    Actually the smallest opening will not give you the sharpest picture in digital cameras, large f stops suffer from diffraction. This effect is well documented and can be seen here -

    Tests and examples
    http://www.secondpicture.com/blog/diffraction_with_small_apertures.html

    Technical info and examples
    http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm

    @Elizabeth Halford
    Thank you for your article, but I can see the point that users like Martin are making. I can accept that the article is meant for beginners but keep in mind some beginners are also very impressionable. And making a blanket statement such as "the max aperture on a f/1.8 is f/2.2" is just plain misinformation and does not do these beginners any good.

    There are reasons why people stop down (sharpness, long shutter times, etc) and there are reasons why people shoot wide open (more pleasing bokeh, faster shutter speed, and yes, because SOME people don't want a tack sharp image, etc). This does not fall in line with your statement about the max aperture on a f/1.8 is f/2.2.

    Anyway I know it's difficult putting your work out there and getting criticised for it so I do commend you for doing so - and the information about lenses having a sweet spot where the image is sharpest is correct and informative. Thank you for sharing.

  • F-64 stopper September 21, 2011 03:35 pm

    Valid point, but what if you want the max depth of field? Wouldnt you want to open up to the fastest, widest f-stop?

  • Ralph Knight September 21, 2011 12:44 pm

    Yes I agree I usually to shoot at f5.6 to f16, as a sort of sweet spot for most lenses. I use fast glass (f1.4 to 2.8) where shallow depth of field is required. The blurred background tends to enhance the fine detail in a shot even when it could be a little sharper ---- Then one can always fiddle with it in photoshop or lightroom.

  • john September 21, 2011 06:59 am

    Maybe you should trash your nikon and canon lenses (according to the author you will be dissappointed at the peformance when wide open with lenses noted) My zuiko lenses 5omm Macro , 14-35swd, and 35-100 lens are razor sharp wide open and razor sharp at all other focal lengths. plus with my E-5 shooting wide open low light photography is phenomenal. Cheers

  • Brian September 20, 2011 02:27 pm

    I appreciate all the instantaneous information available here in cyberspace. I would also like to put out a few words of defense for the a**holes. If it weren't for them, we wouldn't have anyone to compare all the nice & friendly people to. :)

  • Marcy September 20, 2011 02:07 pm

    This is good info and great for beginners to know and understand, but I disagree with the idea that a 1.8 lens is "useless" at 1.8. Just because it's not at its possible maximum sharpness doesn't mean the sharpness you get (combined with the added advantages of a faster shutter speed and/or lower ISO thanks to the wider aperture) isn't good enough for what you want or need. I shoot wide-open with my 50mm (and other lenses) all the time, bc I'm usually indoors so I need the extra light (and I'm also a complete sucker for that uber-shallow DoF) and have gotten results that are stunningly gorgeous. They're not pro-quality, sure, but I'm also not a pro nor do I have pro gear. ; )

    So yeah, great article and great information, but seems odd to say you "can't" use a lens at wide open aperture.

  • Kate September 20, 2011 01:59 pm

    I guess I just love using my 50mm at f/1.8. I love the results, but I also gotta know what I am using this for. Not everything is obviously gonna look great. You have to have a purpose for your picture and the way you take it.

    I was running a test on it and comparing f/1.8 and f/5.6. Here: http://www.flickr.com/photos/katkak8/sets/72157627555624893/

  • Yung Chia September 20, 2011 09:52 am

    @fuzzypiggy

    I agree with you in terms of practice practice practice. Shoot shoot shoot. To quote Henri Cartier-Bresson: Your first 10,000 photos are your worst.

  • Alex September 20, 2011 03:35 am

    I found some "good to know" stuff in this article, since I'm a beginner photographers some things presented in this article helped me. Thanks for sharing.

  • Lena September 20, 2011 01:50 am

    Oh yes, my Canon 50 f/1.4 seems much better at f/2. I noticed that right off the beginning. So what I have been doing when I want a shot at f/1.4 - I shoot one at that and follow it up quickly at f/2. You never know what you are going to get. :)

  • Melissa September 19, 2011 11:11 pm

    I wish I had this article 6 months ago! I was so excited about my prime and took so many shots open all the way to get that great bokeh... And sharpness in portrait photography is very important...probably its a who cares in landscape.

  • Fuzzypiggy September 19, 2011 10:08 pm

    @Steve, I loved this quote, just superb!

    "I laughed uproariously at a post from someone complaining that the problem with their 85mm f/1.2 was that when they were shooting portraits the eyes were in focus but the chin wasn’t…"

    The biggest problem is that people only shoot a few shots and think they know their kit. You have to shoot thousands of shots in all sorts of conditions and all sorts of subjects and then you get learn where the pitfalls are in your kit. People simply think that they can correct bad shooting with more expensive kit, you can't as no optical kit is 100% perfect. People also keep changing their kit so often when new toys arrive, they never get to learn it's foibles and where they must manully compensate.

    Shoot, shoot, play with the kit, shoot, shoot and shoot some more. The more you shoot the more you learn!

  • Yung Chia September 19, 2011 10:06 pm

    I forwarded this post to my brother who's a professional photographer and this was his reply.

    "Remember the pin-hole camera of primary school days? Learnt then that smaller the hole, sharper the image. A person using f1.8 is not PRIMARILY concerned with SHARPNESS of image. Concern is i) getting as much light in as possible (low light conditions); ie., getting A SHOT in rather than NO SHOT. ii)  They want background blurred out so to separate it from foreground. 

    If by SWEET SPOT he means the f-stop producing sharpest images, then primary sch physics will inform him that f-22 will do the trick. Smallest hole = sharpest image. 

    If his 50mm sweet spot is 2 stops above f1.8, there is something wrong with his lens. More likely, something missing in his understanding of optics/physics. I guess what he means is that ANYTHING ABOVE 2 stops from widest aperture will give a sharpness that he finds indistinguishable from f16/22...  Which is probably correct for the untrained eye. But if sharpness is crucial (architectural photography, advertising) then, smallest hole is best."

  • Richard Taylor September 19, 2011 09:23 pm

    Most of my pics are published on the net or prints up to 10x8 (aor A4)

    Some lenses I am happy to use wide open, and by choice sometimes.

    Others only if absolutely necessary.

  • mathOS September 19, 2011 08:39 pm

    Thank you, Elizabeth !

    Yes, I think it is somehow oversimplified, BUT together with some of the comments (the constructive ones, not the aggressive ones), I believe that the thread is very rich for beginners.

    :-)

  • Dewan Demmer September 19, 2011 06:29 pm

    I am left with the feeling that while this article is about the technical it appeals more to a personal. Elizabeth even mentions taking numerous photos at diferent f-stops, now what is to say that what I consider a sweet spot is not really the technical sweet spot.
    Honestly the article simply allows us to consider and perhaps realise that full open is not always the perfect shot technically but then when if the shot we have is perfect to us excellent.

    I recently used my 50mm 1.8 and ran it at 2.2 all the time and I am really happy with the outcome, although I am always learning so now I will go away and play some more. However how would this guide transition to a zoom lense ?

    Look here I used only a prime for this family photos and honestly I have trouble knowing when the sweet spot can be utilised with ease, especially considering light, movement and setup. So much to think of and now a little something extra :P
    http://dsdphotography.co.za/category/family/mnm-deklerk/

  • Phil September 19, 2011 06:01 pm

    What if you don't WANT super sharp images all the time? There's something nice about taking a portrait wide open and having a nice soft look to it, perhaps people want that instead of pin sharpness all the time? This article is stupid. Information only, but don't preach that you can't use a lens wide open and it's a waste of money.

  • Melanie September 19, 2011 01:38 pm

    I didn't know about the sweet spot before your post Elizabeth, thank you. One of the things I like about DPS is that there are articles that appeal to both beginners and experienced photographers.

    Peter Latham, please keep to the facts. A personal attack is of no use and simply reflects poorly on you.

  • Marissa September 19, 2011 11:58 am

    Thank you for all you do Elizabeth. The information you kindly share for FREE with the world is most helpful. It's a shame how nasty people are. I hope you continue sharing your knowledge and experience as I find it most valuable.

  • Christi Nielsen September 19, 2011 09:34 am

    I do have to agree that for beginners it might be a bit confusing for you to say "stops" when it's really "third of stops." However, you were successful in making your point... that your lens isn't necessarily at its sharpest when it's wide open. I recently purchased a 50mm 1.2 and have been testing to see if it's back/front focusing. It's not. It's just better at 1.8 and smaller.

    There is a difference between pointing out someone's technical mistakes for clarification and saying that their articles are laughable. Yes, Peter's comment was mean-spirited.

    Thanks for the article. I knew this, but the more I read about this, the more it confirms it.

  • Scottc September 19, 2011 08:22 am

    I agree with this article 100%. The shallowest of DoFs is not always what we want, and any particular lens will almost always performs its best at a higher DoF.

    I have 2 macro lenses, one fixed and one zoom, and I've seen this with both of them.

    http://www.flickr.com/photos/lendog64/5284996015/

  • javan September 19, 2011 05:06 am

    How do I apply this to my Diana?

  • Holli Brown September 19, 2011 04:37 am

    Well I appreciate it very much. I appreciate when photogs share and help others learning. You'll find that there's always gonna be some people that are going to argue about anything really, but if you've reached just "one" person (which you have), then to me, that's so worth it! (photographer and teacher)

  • Alex September 19, 2011 04:33 am

    my suggestion is try photographing a newspaper with fine print fully open and take a series of shots "stopping down" one f-stop each shot. go from wide open (smallest f number) to closed (largest f number) and display your results at full-size on your computer. it won't take you long to realise that Elizabeth is correct in her assertions. dont worry about the numbers or who is right/wrong - just look at the results. you will soon find which f-stop your lens works best at for you. take into account all factors that are important to YOUR shooting and ignore everyone's "helpful argument". it matters not a bean what anyone else thinks of your photography s'long as you like what you produce! you will generally find the nicest sharpness happens at about two clickety whatsits down from fully open. thanks Elizabeth. nice article.

  • Syntax September 19, 2011 04:33 am

    Generally shooting "wide open" sacrifices so little sharpness that it's not always a thing to care about. On the nifty fifty; I (and some other sites) have found the "sweet spot" to be more around 2.8 than 2.2. Even at 2.8; it's still a good low light lens for the money; and it still looks fine at 1.8.

  • Peter Latham September 19, 2011 04:28 am

    Elizabeth, It's not mean spirited at all. If you are going to put yourself as the expert teaching all those with lesser knowledge than yourself, then you have to get your facts right, which is something you all to often seem to ignore. Just read the comments to your articles, then compare these to the comments on others articles.

  • KirEvse September 19, 2011 04:24 am

    Based on DPReview's test of Canon EF50mm F1.8 II, the lens is the sharpest edge to edge at F3.5 - F5, though it is sharp in the middle wire open. And according to similar review of Canon EF50 F1.4 USM, that lens is the sharpest edge to edge from F5.6 to F8. Both tests with APS-C.
    In my experience F3.2 works great for 50 1.8 and F2.8 for 50 1.4.

  • Heather S. September 19, 2011 04:19 am

    Elizabeth, Please ignore the mean comments and know that your posts are helping a lot of us! I was wondering why my camera always seemed a little less sharp when I used it wide open and kept assuming I must be shaking or something. I'm glad to know (and learn here) that it probably just because the lens is not as sharp at that spot. Thanks so much and keep the articles coming!

  • Dot McQueen September 19, 2011 03:09 am

    Thank you Elizabeth. I'm learning and this is valuable info. It helps to understand that shooting wide open may sacrifice some sharpness.

    I got completely bored with reading through statements from some, shooting you down in flame. Why can't people be pleasant towards each other even if they disagree with what is being said. Constructive comments and additions to the article would be most welcome rather than an attack of the original author!

  • Elizabeth Halford September 19, 2011 03:00 am

    Peter, that is a very mean spirited comment. A lot of my information came from Darren Rowes' post about this same topic back in 2006.

  • Alex September 19, 2011 02:38 am

    I would like to know why all of you people that seem to act like you know it all are even reading this article if you know SO much anyway? Where are your articles trying to help beginners? Really, let's see them since you are all knowing. This article could be very helpful to beginners - some of you must forget that you were there at some point, being a beginner.
    In regards to the comment ...."who is going to notice?" I had to laugh. Is your work mediocre? Maybe looking for the BEST and offering your clients the best is what some of us want. But if you want to present "good enough" stuff - that's your decision.
    You must like to hear yourself talk. Do you also put people down on a daily basis to make yourself feel more like a man? Start your own blog/website/articles regarding photography - since it's obvious you know everything already. Don't be such an a**hole...I know it's hard, but try it out. By saying all of the negative things the normal person reading this article doesn't think - "wow, he really knows what he is talking about". We just think, "that guy is a jackass". Quit embarrassing yourself. It's such a waste of time.
    To Elizabeth, I thank you so much for putting yourself out there and trying to help all the newbies. Your positive attitude is what the photography community really needs.

  • Peter Latham September 19, 2011 02:27 am

    The whole idea about writing these articles is to inform people and this requires the information to be correct. If you can not get a simple thing right about whole stops and thirds of stops, why should we believe anything else you write about.
    On the whole most of your articles do give of us a good laugh, just as long as too many people don't take you too seriously.

  • Elizabeth Halford September 19, 2011 01:41 am

    You're all right that these details pertain purely to the technical side and probably won't make much difference in real life. But you fail to recognise that the only reason you have the luxury of having such large opinions is the fact that somewhere along the line in your studies, someone told you what I have written here and you already know about it and have moved on. So allow other beginners the space to read things like this for their own enlightenment and if it doesn't enlighten you because you already know it, then you have two options: 1.) you may contribute to the discussion in a constructive way or 2.) take it as a sign that you're on the right track and move on to another post that can add to your education.

  • mcguireuk September 19, 2011 12:30 am

    I think that from a technical aspect this is a problem but out there in the real world it makes little difference. Unles were producing large prints who's really going to notice the dif between wide open and stopped down a little unless you using a really bad example of a lens. I've got a canon 50mm 1.8 and use it at all sorts of apertures and unles i'm printing large it really doesn't matter.

    Don't be put off using wide open. sometime its either that or no shot at all and it souldn't be compromised just based on pixel peeping. I would says that this sweet spot is more useful to consider only absolutly needed such as macro work.

  • Zaman September 19, 2011 12:22 am

    I wouldnt let this get in the way, on some of my lenses i tend to think wide open is there when i need it, if not i usually stop down 1.8 lenses to 2.8 but some of my lenses like 105 2.8 or 70-200 2.8 are absolutely fine wide open very little difference stopped down. I think you just have to know your own gear and its limitations. Also alot of people are saying 1.8 is better than iso 3200? is it? if you want sharper results than you will need a lower fstop and with some of the cameras today, iso 3200 really isnt all that bad at all.

  • Chris September 18, 2011 11:27 pm

    @dominik
    I often shoot at f1.8 iso 3200, or f2.8 iso 3200, but I usually try to keep iso at 1600 or below, If i was worried about lens sharpness, and stopping every bit of motion blur, I'd be shooting at iso 12800.

    as long as you have good glass, it isn't really a concern. I have a couple fo cheap lenses which really need to be in the middle of their range to have acceptable sharpness, but my main lenses are acceptable all the way through (despite being slightly sharper in the middle)

  • Dominik September 18, 2011 09:43 pm

    @chris
    this will produce some lovely experimental shots at night or great black and white. Especial for this type of photos I would use my Sigma 30mm f/1.4. I love to shoot with this lens wide open. Irregardless of some kind of negative effects. If you own good glasses, you will notice that you became addicted for shooting wide open. F/1.4 rocks

  • Chris September 18, 2011 09:08 pm

    @dominik
    How about f1.8 AND iso 3200? ;)

  • Dominik September 18, 2011 08:51 pm

    Your article about useable aperture is too simple. If you want a shallow depth of field or a low iso for taking photos in a church, then yo have to open your aperture. Yes, there is a compromise between a good bokeh, sharpness and high iso, but some lenses allow you to use wide apertures. The Canon 50mm f/1.8 is a bad example. The Canon, Nikon, Pentax, Sony 50mm f/1.4 all together works great at apertures of f/2.0. If you shooting portraits of one person, there is no need to go for apertures like f/2.8 or f/4.0. If you shoot landscapes or groups or architecture, then you would never use such f-stops. You would use f/5.6 or f/8 for maximum sharpness and a maximum depth of field. And concern there are a lot of lenses that produce great sharpness even at full aperture, but they produce a ugly bokeh. You have to concern a lot of compromises. Learn to know your equipment! And yes, better f/1.8 than iso 3.200.

  • gipukan September 18, 2011 07:28 pm

    Well said Steve. I can only add using a tri- or mono pod for stability and disable your is/vr if you have it. My 20 F/2.8 and my 50 F/1.8 are able to capture theater play in poor light. My 28-135is F/3.5-F/5.6 can't cut it w/o flash. Sure you can raise ISO and post-process but not if the dark was not recorded.

  • Phil G. September 18, 2011 05:44 pm

    Elizabeth,
    Thank you for your informative article. Beginners, as you note, will probably be surprised at this but the info is consistent with what has been taught for many years. That lenses wide open and stopped down all the way are not at their best...The mid apertures are and always will be the sharpest overall. And you will even find differences between 2 of the exact same lenses. They are miniscule but differences nonetheless. There are some manufacturers who make better lenses than others and you will usually pay more for those. In the large scheme of things, this will not make much difference to most. Just my opinion of course...Thank you again. Always enjoy your articles.

  • Jai September 18, 2011 03:28 pm

    How will the sweet spot vary for a zoom lens ? i have 18-200 .Will it vary for each focal lengths or will it be same f-stop value for all focal lengths.?

  • Lee Young September 18, 2011 03:10 pm

    who really cares about sharpness? I can get hair splitting sharpness at f/8 or f/11 but I loose all the bokeh, subject isolation, artistic intent and all other things that REALLY matters.

    modern lenses have enough sharpness at the centre at their widest aperture for most applications. Sharpness isn't important nowadays, just like the number of pixels. In fact, by simply using a camera with higher resolution you can almost always get a more detailed and sharper-looking picture. Want ultimate sharpness? Shoot film and scan it at 5400dpi.

  • Hagen September 18, 2011 12:26 pm

    I buy extra wide for the narrow DoF. Sharp? Majority of my 15MP images are printed at 13x19, so no problems.

    Use the weapon of choice for your purpose, and the _end result_: web, size of print, size of display for digital.

    otherwise, what is written here is true: you want the widest aperture with the best sharpness? Then this article is for you: all you others, quit beating on E, and get out of your own operating space

  • Erik Unger September 18, 2011 12:11 pm

    @Steve

    IS/VR won't help when shooting action. Try shooting a band playing in a dark, grungy, basement bar or a high school sporting even at night. Getting the extra 2 or so stops of IS/VR isn't going to get you the shots. Having the incredibly wide aperture will.

    Now if you are shooting a portrait with plenty of light, there is no need to shoot at 1.2 or 1.4... depending on how far away your subject is of course, but saying you will never need to shoot that wide is just ridiculous.

  • John Woods September 18, 2011 12:08 pm

    Your article references thirds of stops as full stops. And since each stop is a main component of this article, it has rendered itself almost completely useless. Hate to say it, but the editor's should have caught this one on the way up.

  • Steve2 September 18, 2011 11:38 am

    I have a question. Say you have a 50mm 1.2 and a 50mm 2.0 lens. Set them both to f2.0, will you have the same shutter speed? assume you are using aperature priority.

  • Frank Little September 18, 2011 10:51 am

    I am wondering why nobody brought up that with a cropped camera you live in the sweet spot. Isn't it true that sharpness is usually decreased on the edges. This edge performance on a 50mm lens that was made for a full-frame camera should be off the edge of the frame in a cropped camera, no?

  • ccting September 18, 2011 10:39 am

    Nikon 35mm f1.8 sharpest at f2.8. Well, you just need to see Kenrockwell or other website then you know how the len acts. MTF curve describe how a len will act.. that is secondary for me as i only have 1 len VR Kit 18-55mm (sharpest at 35mm f8)

  • Rick September 18, 2011 10:11 am

    Steve: Aperture influences more than just shutter speed. Some people actually utilize a wide aperture for their desired DOF.

  • Gautsch September 18, 2011 09:38 am

    As for everyone on here slamming the author:
    The point of this article was obviously to educate photographer newbies about lens sweet spots..so what if the maths is a bit off, sweet spots do exists and many people don't know about them. Yes, the difference in sharpness is hardly noticeable most of the time, but that still doesn't make it BS.

    Please be kind on the Internet...there are too many a***holes out there as it is.

    Thanks for reading,
    Gautsch

  • Gautsch September 18, 2011 09:34 am

    Steve,
    IS/VR is great for still subjects but no use for moving ones. Street photographers who want to capture the action as it happens, especially in less than ideal lighting conditions, still need fast lenses. Furthermore, at the distances that you normally take pictures of people of in te street, shallow depth-of-field usually isn't an issue..it only becomes one if you're too close to your subject, using a fast tele prime.

    Rather than laughing 'uproariously' at things, it might be better to take it easy a bit on so-called 'prime fanboys', watch, listen, read, compare and learn.

  • Verena September 18, 2011 09:18 am

    Seems we have differences in opinion on this topic, interesting! I just know that with the lenses I have I better use some sharpening in post-processing or else I get photos that just look slightly too soft for my liking and that is at all apertures. This is just what you have to live with if you can't afford a Leica M9 and a Noctilux f/0.95 (hello Steve). And even if you have that lens, I imagine that focusing correctly with it is a bit of a difficult job too ...

    In the end it's always a trade-off. And tbh: nobody notices these things anyway.

  • af September 18, 2011 08:51 am

    Elisabeth, I have enjoyed many of your earlier articles, but you just don't know what you're talking about here.

  • Steve September 18, 2011 07:48 am

    Don't mention it to the fast wide prime fanbois but...

    It's one of the best reasons for spending money on an IS / VR lens.

    So rather than an extra half a stop of speed you can shoot at or around the sweet spot.

    And before the bokeh fanbois get started.

    I laughed uproariously at a post from someone complaining that the problem with their 85mm f/1.2 was that when they were shooting portraits the eyes were in focus but the chin wasn't...

    You should buy the lenses that work for you.

    Rather than believing the people that tell you a "street photographer" uses a Leica M9 and a Noctilux f/0.95. I laughed long and loud at that one too.

    In a lot of cases it's about bragging rights or having more money than sense.

    Surely the test of a good photographer is that they can work with the tools they have?

  • Josh September 18, 2011 07:45 am

    I'm with Martin. Part of the point of shooting wide open is to have shallow DOF, not maximum critical sharpness. This lens "flaw" actually helps many times in portrait photography, since most people don't want extremely sharp renditions of themselves. This is why almost every portrait and wedding photographer uses fast primes for portraits. Most of the time taking just a bit of edge off helps. That being said, I've found the higher end Canon primes to be very very good wide open. Not as critically sharp as stopped down, but when shooting wide open its more about the feel of the image anyways... you don't do copy work where absolute edge to edge sharpness is required by shooting wide open.

  • Rob-L September 18, 2011 07:22 am

    I think you need some help understanding f-stops. You state "A good rule of thumb is that a lens starts moving more towards perfection about two stops above its maximum aperture." Then you give the example of a f/1.8 "moving up a couple stops to f/2.2 or f/2.8" That's not one/two stops. One stop up from f/1.8 would be f/2.5. Two stops would be f/3.5

    Also, stop the pixel peeping madness. You lose some sharpness on the edges maybe, but I'd still have no issues opening a lens to it's max aperture without hesitation if I needed to.

  • Craig September 18, 2011 07:12 am

    @Martin
    A little harsh. The writer has been Shooting for years. I think her point was to inform the uninformed about sweet spots and image sharpness. I don't think we're supposed to literally not shoot wide open. I think she means shooting wide open does not guarantee maximum sharpness on all/any lenses. I suggest if you have such strong opinions to the contrary that you offer up your services and do a write up for dps.

  • Mike Falasca September 18, 2011 07:08 am

    "Try moving up a couple stops to f/2.2 or f/2.8 and compare the results you achieve."

    From 1.8 to 2.8 is just a tad over 1 stop, unless i am misunderstanding things !

  • Devansh September 18, 2011 07:01 am

    As Chris said, "Good to understand things like this, but you really have to wonder… Who the hell is going to notice???" this is the kind of thing that an average person doesn't even notice. Not even a photographer. Besides there are a million ways to sharpen a picture during post processing, and unless you are making a 10 ft print, you have nothing to worry about. This is the kind of information which is good to know but absolutely useless in real life.

  • Florin September 18, 2011 06:56 am

    Well, I appreciate the article but it's really only one side of the story. Yes, maybe the cheap nikon and canon primes are behaving as you described, but there are some other lenses that have a very usable max aperture. Let me give some situations:

    The 1K Canon 50mm f/1.2 is almost as sharp as the 50mm f/1.8 at max aperture, and by 1.6 is sharper (center) than the 50mm 1.8 at max aperture. But then the canon f/1.2 Canon is not such a great lens at max apertures.

    Let me give you some further examples: the Leica 50mm Noctilux is probably sharper at f/0.9 than any other 50mm ever produced (well maybe the summilux is still sharper at 1.4, its max aperture). What I am saying is that Leica lenses, and some Zeiss lenses for that matter trade nothing at their maximum apertures.

    So it's a bit of stretch to say that

    "When talking about 50mm lenses, you could say that…
    the max aperture on a f/1.8 is f/2.2
    while the max aperture on an f/1.4 is f/1.8
    and on a f/1.2, it’s going to be f/1.6"

  • Lou September 18, 2011 06:53 am

    Too.........the operative word here is sweet spot. Ok that was two words....but I digress.

  • Lou September 18, 2011 06:50 am

    I like Martin's summation.

    A wide open aperture is better than a 1600-3200 iso anyday.

  • Chris September 18, 2011 06:39 am

    Good to understand things like this, but you really have to wonder... Who the hell is going to notice???

    Understand it but don't worry about it. On any well made lens the difference will be too small for a "normal client" to notice.

    The real issue is people shooting wide open no matter the shot instead of choosing an appropriate aperture for the appropriate DOF. A fast lens can be used at f8 too.

  • gipukan September 18, 2011 06:38 am

    Found the same on my ef 50mm f/1.8 and learned it the hard way. Now i have a 20mm F/2.8 and found it best at F/4 till f/8. Great write up!

  • F September 18, 2011 06:31 am

    Ill take that with a pinch of salt. My 85 1.2 is sharp throughout all apertures.. may not be the case for you though

  • Martin September 18, 2011 06:29 am

    "I can hear you thinking: so I just spent over $1k on an f/1.2 and I can’t actually use my lens at f/1.2?"

    Really? You CAN'T use it at f/1.2?

    Sorry, but this is ridiculous. The article went from informative to just plain stupid very quickly. No, a f/1.8 lens isn't at its sharpest wide open. Then again, it's not at its sharpest at its smallest aperture either. That doesn't make it worthless on either end of the aperture spectrum, it just means it suffers the same problem EVERY lens ever does: it has sharp apertures, and less sharp apertures. That in no way means you CAN'T use your lens on those apertures, in fact it'll work just fine. It'll probably even give you your money's worth. I know my 30mm f/1.4 did. See, compared to ridiculously high ISO or severe camera shake, I'll take a tiny bit of lessened sharpness any day.

    It's all about what you use it for. If what you're after is maximum optical sharpness, what are you doing shooting on ultra-wide apertures anyway?

  • Kathy September 18, 2011 06:18 am

    Awesome article! I just realized that most of my "focus" issues aren't "focus" issues....it is the bokeh from using my camera wide open....hehehehe! I'm really glad you put this out there for baby photogs like me!

  • Scott MC September 18, 2011 06:14 am

    I converted a Canon FL 55mm f/1.2 for EOS, and it has a nice sort of effect wide open, it should be a great portrait lens if I can get around to shooting like that with it.
    http://tweed360.com.au/2011/09/06/1983-circuit-board/
    http://tweed360.com.au/2011/09/07/pepsi-can/

  • Jean-Pierre September 18, 2011 06:10 am

    Super-Takumar 50 1.4 ~ at about f4-5.6

  • Jack September 18, 2011 05:54 am

    old stuff....

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