Question!

[Murkar]

Alright, so, I'll link to a photo by Rob Sheridan below. My question is with regards to the colour and lighting in the photo below. Has anybody ever had experience with this? I'm just wondering how you think the photo was taken; i.e. is there a sillhouette around the edge, or is it just flash fall off? Post processing? The colours look quite saturated to me, and the contrast looks high, but it's also clean and quite sharp looking. Have a look and let me know what you think...

(I'm just getting into photography, so these are probably sad questions for you all to hear, but I'm still learning)

http://rob-sheridan.com/tourist/tokyo/tokyo05.jpg

Some of the best photos I've seen in a really long time are here on Rob Sheridan's travel photography page (Tokyo): rob-sheridan.com photography : tokyo, japan, august 2009.

[inkista]

Looking at the EXIF, the shooter used a 5D Mk II, and probably a 70-200 f/2.8L IS USM (the focal length on the photo is 105mm; the aperture is f/2.8). So, the color's from the L glass and probably good post-processing technique, and the thin depth of field is coming from the long focal length, large aperture, and full frame sensor in combination. It's not a vignette--it's the depth of field blurring objects in front of and behind the focus point.

[Murkar]

Thank you for the reply! It is quite helpful, it's given me a bunch more to research. I do understand depth of field; perhaps the photo I posted was a bad example. It just looks liek the other photos become dark towards the corners.

I have a couple more (proabably stupid) questions that I really need answered, if anybody would care to reply.

First off...what is a full frame sensor and how does it differ from other sensors? I've heard it quite a bit, but don't really know much about it. (Also, what is 'The L glass?')

Thanks

[OsmosisStudios]

Originally Posted by inkista

and probably a 70-200 f/2.8L IS USM (the focal length on the photo is 105mm; the aperture is f/2.8).

Does Canon not make a 105mm f/2 prime? Just a thought.

"L glass" refers to canon's series of lenses with an L designation in their name (16-35 f/2.8L, 24-70 f/2.8L, etc). This series encompasses lenses that are built to higher standards using better materials and optics. The special optics make these lenses very sharp with fantastic contrast and so on. Theyre also expensive, but well-worth the price to some.

A "full-frame" sensor refers to a photo sensor that is the same size as a piece of 35mm film. Most cameras (well, all but the 5D and 1Ds series, for Canon) have a sensor thats just shy of HALF that size. Larger sensor means a lower pixel density (less pixels per sq in) and an easier time with certain effects (depth of field, for instance)

[inkista]

Originally Posted by Murkar

First off...what is a full frame sensor and how does it differ from other sensors? I've heard it quite a bit, but don't really know much about it.

A full frame sensor is a sensor that's the same size as a frame of 35mm film: 36mm x 24mm. It's considerably larger than entry level dSLR sensors.






The larger sensor doesn't actually make the DoF shallower, but to get the same composition on a larger sensor, you'll use a longer lens, and that will give you a shallower DoF than if you used an (equivalent) shorter lens on a crop body. Larger sensors also have a lower pixel density (i.e., the individual pixels are larger), so they have better high iso noise performance. Most of the effects of sensor size on digital images is described in this article.

(Also, what is 'The L glass?')

The L designation is one that Canon puts on its professional line of lenses. It can stand for "luxury" or "low-dispersion glass" depending on which Canon literature you read. Typically, an L will be the most expensive lens of a specific type, have the largest max. aperture, and the most features (IS, USM, etc.) The telephoto zooms are often weather-sealed and white. Technically, an L lens will have at least one exotic glass element in it, either flourite glass, or something else with low dispersion characteristics, which means the lens will exhibit high contrast (which in turn increases sharpness) and low chromatic aberration. There are only three L lenses under $1000: the 17-40 f/4L USM (~$750), the EF 70-200 f/4L USM (non-IS) ~$650, and the EF 200mm f/2.8L USM (~$750), so just assume a four-figure price tag when someone mentions an L lens.

Some folks on boards will often say something idiotic like, "you should only buy Ls". Ls are terrific, they do amazing things other lenses don't do (which is why I own three). But they're really expensive, they're big, they're heavy, and sometimes they only offer a marginal improvement over a much cheaper USM lens. And in the case of the 85L vs. the 85/1.8, the autofocus performance is much slower on the L. Ls, like all lenses, have individual characters, and specific tradeoffs. Sometimes an L is the only answer to a specific shooting problem. Sometimes, it's completely unnecessary. You don't need L lenses to take good pictures, and learning to stop down and to properly post-process images can considerably narrow the gap between consumer and pro glass results.

[inkista]

Originally Posted by OsmosisStudios

Does Canon not make a 105mm f/2 prime? Just a thought.

Not in EOS mount. We've got a 100mm f/2 USM, a 100 f/2.8 Macro, and a 135 f/2L USM, so I'm pretty sure it's one of the 70-200 f/2.8s. All the walkaround zooms that cover 105mm are f/4 or slower. Given that he's shooting with a 5DMkII, I'd also assume the IS version.

[OsmosisStudios]

Man, how does Canon not have a good 105mm portrait prime. Yeash :P

[Murkar]

Thank you both, you've been extremely helpful

[PrimeTime]

Originally Posted by OsmosisStudios

Man, how does Canon not have a good 105mm portrait prime. Yeash :P

Because they have the 135 f/2 L, which is even better

Test Notes
As the reader reviews below testify, this is an absolutely stellar lens, probably one of the sharpest and most distortion-free that Canon makes. It starts out very sharp at f/2.0, gets even sharper at f/2.8, and softens only slightly at f/11. At f/32, it's pretty soft, but less so than a lot of lenses at that aperture. (Suggesting that diffraction limiting is only part of the story with lens softness at tiny apertures.)

As you'd expect from a premium prime lens, both maximum and average chromatic aberration is very low across the aperture range, with the maximum CA on the order of 0.02% of frame height regardless of aperture. Exposure uniformity (vignetting) is also really excellent, reaching a maximum of 1/4 EV (on a camera with an APS-C size sensor) at f/2, and dropping to well under 1/10 EV at f/2.8 and above. The lens shows a very slight pincushion distortion, but it's well under 0.1% of frame height, an excellent performance by any measure. Finally, although we don't explicitly test for it, we have to note that this lens' bokeh (rendering of out-of-focus objects) is really excellent as well. Fit and finish are first-rate as well, with very smooth manual focus operation, and very fast autofocus on the camera.