Apreture queries

[dimitrz]

Hi

I would be travelling to mountain country soon and am trying to hone my aperture selecting skill lol

I was studying a lot of photographs and was perplexed why some people have opted for a mid range Apreture instead of the smallest aperture in range of F/20 to give more DOF

Do to copyright reasons I am including the links to the photos rather than the photos itself

http://www.trekearth.com/gallery/Asi...oto1069003.htm

http://www.trekearth.com/gallery/Asi...oto1067891.htm

Exposure: f/8, 1/125 seconds

Do you think the above photos would have been ruined if taken at say a f/20 or smaller aperture ?

What’s the logic of taking these at the current aperture ?

I was planning to go all out with F/20 on a steady basis to get the best possible DOF (on long scenes) - is that wrong?

Question 2

When faced with scenes like below , should I tweak my EV with 2 stops right +1 or +2

http://www.trekearth.com/gallery/Asi...oto1065354.htm


Thanks

[Digidave]

Will you lugging around a tripod? If you take a photo at f/8 at 1/125, then change your aperture to f/16 your shutter speed will be 1/30, f/22 would be 1/15.

I think you'll find f/8 will give you the best shots. It's the "Sweet Spot" for most lenses & will give you plenty of DoF for most landscapes.

When you get above f/16 your photos will start to get a funny appearance. Someone else will have to give you the technicalities of it. I forget what it's called. Sorry!!

I would just stick with f/8 unless it is so bright out that you need to close down your aperture to achieve proper exposure.

[kencaleno]

You start losing definition after f11 due to diffraction,so don't go smaller. For total depth of field,you need to use hyperfocal distance points- for example. at a lens focal length setting of 18mm at an aperture of F 11,focused on a point 1.5 meters away,your depth of field extends from 0.754.3 meters to infinity,Here are my hyperfocus charts for 18-55 and 70-300 kit lenses: Regards, Ken

PS: It pays to expose on the minus side,for general photography-exposure compensation set to -0.3 to save blowing highlights-but for snow +2 or snow will be grey.

[navcom]

Ken is right about diffraction. When you approach the smallest aperture, you loose sharpness and detail. But I would disagree that you shouldn't go smaller than f/11. If anything smaller than f/11 produced terrible results, the lens manufacturer wouldn't bother producing anything smaller than f/11. I consistently use f/13-16 on my lenses without any real issues. I've achieved some very detailed results on landscapes using f/16. And the DOF is fantastic if you understand the limitations.

See attached image. This is one of my best-selling photos. The DOF is wonderful and it's pretty sharp...not much PP done for sharpness...just for the desaturation effect.

EXIF data: Pentax K10D, Tamron 28-75mm, ISO 100, 6 second exposure, f/18

Not too bad for such a small aperture. Of course, if it had been bright sunlight, I probably would have used something around f/13 or so. That's only because I know that with this particular lens, bright light will affect detail more at these smaller openings. I used f/18 because I really wanted maximum DOF.

It's the same on the other end...you loose quality when wide open as well, which is why you should stop down at least 1 or 2 stops for best image quality unless the situation requires a fast exposure.

For most landscape work, f/16 is not needed. And Ken's advice on hyperfocal distance is spot on...use it.

Of course it is dependent on your lens as every lens is a bit different. If you know the limitations of your lenses, then you can anticipate the results. For tha attached picture, I knew ahead of time what I could get from the lens. If I didn't know, I probably wouldn't have used f/18.

[dimitrz]

Thanks everyone for the valuable advise

Yes I would be lugging my tripod with me.

Regarding the hyper focusing aspect I a a bit confused...do I need to enable any setting on the camera to achieve hyper focusing ? I use Nikon D80 recently bought and I didnt see any Hyperfocus info in the manual

[kencaleno]

Originally Posted by dimitrz

Thanks everyone for the valuable advise

Yes I would be lugging my tripod with me.

Regarding the hyper focusing aspect I a a bit confused...do I need to enable any setting on the camera to achieve hyper focusing ? I use Nikon D80 recently bought and I didnt see any Hyperfocus info in the manual

Your manual has been written by engineers, not photographers-Your manual will not teach you photography-It will only teach you what camera functions do.For hyper focus you only need to set aperture,Then focus at correct distance for focal length of zoom being used. Regards, Ken

[OsmosisStudios]

Originally Posted by kencaleno

PS: It pays to expose on the minus side,for general photography-exposure compensation set to -0.3 to save blowing highlights-but for snow +2 or snow will be grey.

I'd actually advise against that, especially if one shoots RAW. You can pull a lot more from highlights than you can from shadows in post if youre really trying.

I've also noticed that some of the newer dSLRs are underexposing by a fair margin.

[fletch]

My advice would be to try to understand the underlying issues and then react to them out in the field rather than relying on rather suspect 'rules'.

Saying never go smaller than f/11 is just as useless as saying always shoot landscapes in f/22.

They key is understanding which concepts are affecting the shots you take. Diffraction is an issue with digital cameras and it is true that below about f/11 photos can become less sharp due to the effects of difraction. It is also true that at f/22 you will have more depth of field that at f/11 so you can get more of your shot in focus.

So when you are greeted by your landscape you need to weigh up the pros and cons in your mind. Can you shoot at f/11 and mimise the amount of difraction or do you need to use a smaller aperture to get all of the scene in focus? If so is f/16 ok or do you need to go to f/22? A shot with everything in focus but some difraction is better than a blury shot without any difraction but if you can both in focus and no difraction then why wouldn't you go for that.

Part of making this decsion is understanding what will be in focus at different apertures and hyperfocal distance can help with this. Google it or look at http://www.dofmaster.com for more info. It can help to have a print out of the hyperfocal distances for your lens in your camera bag.

[kencaleno]

Originally Posted by fletch

My advice would be to try to understand the underlying issues and then react to them out in the field rather than relying on rather suspect 'rules'.

Saying never go smaller than f/11 is just as useless as saying always shoot landscapes in f/22.

They key is understanding which concepts are affecting the shots you take. Diffraction is an issue with digital cameras and it is true that below about f/11 photos can become less sharp due to the effects of difraction. It is also true that at f/22 you will have more depth of field that at f/11 so you can get more of your shot in focus.

So when you are greeted by your landscape you need to weigh up the pros and cons in your mind. Can you shoot at f/11 and mimise the amount of difraction or do you need to use a smaller aperture to get all of the scene in focus? If so is f/16 ok or do you need to go to f/22? A shot with everything in focus but some difraction is better than a blury shot without any difraction but if you can both in focus and no difraction then why wouldn't you go for that.

Part of making this decsion is understanding what will be in focus at different apertures and hyperfocal distance can help with this. Google it or look at http://www.dofmaster.com for more info. It can help to have a print out of the hyperfocal distances for your lens in your camera bag.

It is hard to believe the naivety here-you always want to argue an undisputable fact-If you look at each image you take at 100% (actual Pixels) you will realise the truth that F 11 is as small as you want to go-Unless you are shooting macro-Ken

[navcom]

Originally Posted by kencaleno

It is hard to believe the naivety here-you always want to argue an undisputable fact-If you look at each image you take at 100% (actual Pixels) you will realise the truth that F 11 is as small as you want to go-Unless you are shooting macro-Ken

Ken...I think it's more of a give-and-take here. It's all based on what you need. There are times when I am willing to sacrifice a bit of sharpness to achieve better DOF...especially when the loss of sharpness is so minor. I can't honestly accept that I should never use anything smaller than f/11. I understand your premise, but there are times when it is useful to have a smaller aperture. I have paying clients too, and they are willing to spend on prints where I have used f/16...even f/22.

The bottom line is "what works for the artist". For myself, I have no problem using a small aperture if required. I hover around f/8-f/11 for most of my landscape work, but I have no issue going smaller if the DOF is required.