Tag Archives: resolution

Commentary, Ideas, Tongue in Cheek

Regarding Sharpness. And Obsession.

3 Comments

We have all seen the lengthy discussions about “which lens is sharpest.” While the ability of a lens to resolve detail is certainly important, it is not the only thing that is important. And in many cases, knowing which is the sharpest lens is not as important as know which among a number of sharp alternatives best suits your needs. I stumbled into another discussion of this topic online today and posted the following as my contribution. (Slightly edited here from the original post.)

Folks sometimes allow themselves to become completely distracted by “sharpness” to the point that they overlook a whole bunch of other important issues in their quest to find the holy grail of “sharp.” This can become the equivalent to realizing that good tires are important on a car, and then deciding to buy a particular car because it comes with the “best” tires… but is too big to fit in your garage, costs twice your annual income, has a terrible repair record, needs a tune-up every 750 miles, and only comes in a color your spouse hates.

For a few people doing certain types of very critical work, printing very large, working slowly and methodically, and willing to forego the compensatory advantages of other lens options, lenses like the excellent TS models, lenses from another manufacturer that only work with adapters, classic primes, and so forth might make some sense.

But just because a lens might measure a bit better to some extent in one of the areas that is measurable (e. g. “sharpness”), it does not necessarily follow that it is a better lens, nor that alternatives that may measure differently in sharpness – but are very nearly as good – will not also be excellent performers. It is also not true that these specialized lenses are required to produce large and effective prints.

It is interesting to watch people go through a process that may look something like the following at times, as they…

1. decide they need a sharper kens.
2. research lens sharpness.
3. consider only sharpness and overlook or dismiss other issues, including those mentioned in the sources analyzing sharpness.
4. decide that some lens is the “sharpest” – frequently some expensive prime, the most expensive zoom they can find, an alternative brand, a specialized TS, etc.
4.5. lust after said lens for some period. The excitement builds…
5. purchase the aforementioned Really Really Sharp Lens.
6. use the new lens and glory in it’s pure Divinely Sharp Wonderfulness, thereby confirming their wise choice.
7. share their wonder with others.
8. make more photographs, and eventually come to find out that a) in real photography the sharpness difference is rarely visible, b) there are downsides to using the sharper lens, c) the downsides sometimes compromise or lose the shot, and d) in many cases their previous “less sharp” lens proves just as useful and effective.
9. note that the new super Super Lens, while useful, begins to spend more time in the bag, and…
10. learn an important lesson or two about Lens Lust… or else repeat the cycle with a different WonderLens. :-)

To be clear, I’m not suggesting that sharpness is unimportant. I’m just encouraging people to keep things in perspective.

G Dan Mitchell Photography | Twitter | Friendfeed | Facebook | Facebook Fan Page | Email

Commentary, Equipment, Tests

Canon EOS 5D II: Early Observations on Image Quality

1 Comment

I posted earlier today about increasing availability of the Canon EOS 5D II at places like B&H, so I thought it might be useful to begin posting on some of my experiences with the camera during the couple of weeks (and perhaps a thousand frames) that I’ve had it. Here is a copy of something I posted elsewhere earlier this week, in response to a post concerning image quality from this camera:

I’ve shot with cropped sensor bodies extensively in the past. I have shot with a full-frame 5D for the past two years. I recently began shooting with a 5DII and have done a thousand or so frames with it.

I cannot see image quality problems in my images, even in those that stress the ability of the camera in ways that should produce them if they are there: shooting wide dynamic range scenes, using high ISOs (up to 1600), inspecting at large on-screen magnifications, and making careful prints.

My photos have very low noise all the way through the shadows to pure black, even in some photographs where I’ve pushed the shadows either during RAW conversion and/or via the shadow/highlight tool in post. I’m seeing very highly detailed images with smooth tonal transitions. As far as I’ve seen the 5D II has a rather substantial dynamic range – as reported in a number of tests – and it is at least as great as that of the 5D.

Let me repost a couple of 100% magnification crops that I posted elsewhere from the 5DII.

The first was shot at ISO 100 at, IIRC, f/16 using a 35mm prime with the camera on tripod. The crop is a 100% magnification section from the very far lower right corner of the shot. The dark areas were pushed slightly, too, so if there were noise anywhere it would certainly appear here – but I don’t see it even at this resolution, which would be equivalent to a print width of five or six FEET wide. Seems like pretty good resolution to me! (It also speaks well for the EF 35mm f/2 lens.)

The second example is pretty much a noise “torture test” – it is a very dark section of a much larger image. (Again a 100% crop). It was shot using a 100-400mm zoom handheld at ISO 400 in cloudy conditions. There is some noise in the shot, but that is entirely normal – and this noise would be completely invisible even in a very large print. (The pattern on the lighter fabric near the left side of the frame is that of the fabric itself.)

My observations from 100% on-screen pixel peeping are confirmed by the more important test of printing.

(If my post has helped you with a purchase decision, making your purchase from B&H through this link will help support the blog. Thanks!

Equipment, Tests

Using Prints to Test Four Canon DSLRs

Leave a comment

Miles Hecker has posted interesting test results in his Canon EOS big guns image quality shootout:

As some of you know, I am a landscape photographer. I migrated to full frame digital SLR’s from medium format film. I used to shoot 6×4.5, 6×7 and 6×9 film with the end product being prints of 20″x30″ and larger. As such, I chose to investigate only one area of the 5Dmk2 in this exercise, overall image quality or IQ for short. For this test, I decided to construct a still life with a wide range of color, lots of detail and very controlled lighting to obtain what for me are valid results.The test would produce 100% crops for pixel peeping. The final analysis of IQ however would be made using real life obsevers and detailed sections of 16″x24″ and 20″x30″ photographic prints.

What I like about his test methodology is that it eliminates the very difficult issue of normalizing on-screen tests of cameras with different sensor sizes and photosite densities but doing something that I have felt would make the most sense, comparing large prints from the different test cameras. In this case he tested the Canon EOS 1DsM3, 5D2, 5D, and 50D. 

I won’t spoil the fun by telling you the results here, but let’s just say I’m not at all surprised at the results.

Equipment

Canon EOS 5D

1 Comment

Having used my Canon EOS 5D extensively for about two years, I figure it is about time for me to write up something about my experiences with and impressions of this camera. Rather than try to compete with the existing camera review sites and post a bunch of technical specifications and test results, I’m going to focus on aspects of the camera that may give a better general idea of its strengths and weaknesses and of situations for which it is best adapted. Continue reading Canon EOS 5D →