‎”The craft has to be there but it can’t be a fetish, and the spirit has to be there or it isn’t worth doing” Ansel Adams, March 1975.

Thank you, Alan.

The Pentax K-01 got announced today, but by B&H, not by Pentax. Oops. At first blush, it looks like it could be an alternative to the NEX-7 for photographers wanting a small camera with a big lens selection, but it has two fatal flaws.

APS-C sensor? Check. No mirror? Check? 16 MP? Check? Anti-shake with sensor motion? Check. Eye-level finder? MIA.

So what’s not to like beside the missing eye-level finder? The K-01 will take Pentax K-mount lenses. That’s a good thing if you’ve got a drawer full of them. It’s a good thing for the sensor designer because, with a flange distance of 45.46 mm, it will be hard to get really oblique ray angles. However, it’s a deal killer if you want to use Leica M lenses, which have a flange distance of 27.95 mm. You can’t use Leica screw-mount lenses, since they have a flange distance of 28.8 mm. You won’t be able to use Canon EOS lenses, with their 44 mm flange distance. It’s going to be hard to use Nikon F-mount lenses, since their flange distance is only 1 mm more than the K-mount lenses.

The K-01 may turn out to be a great camera for the market the Pentax product managers were aiming for, but for photographers looking for lens flexibility, it’s a non-starter.

The purple corner effect is fixable using Photoshop tweaks or programs like Cornerfix. Effective use of either requires calibration images. In lenses that exhibit moderate to strong purple corners on the NEX-7, apertures wider that about f/5.6 require their own calibration images.

That’s a lot of calibration images to keep track of. One for each lens at f/5.6 or f/8, and one for each lens at f/4, and f/2.8, and f/2, and so on until you reach the maximum opening for each lens. If you’re a real perfectionist, maybe you’ll do images at half or third stops. The worst part is figuring which calibration image to use. You can probably remember, and add to the keyword list before you forget it, which lens you used. But can you remember the aperture? The NEX-7 will help you with neither datum; once you put a non-Sony lens on the camera, it doesn’t know what kind on lens it is, or what aperture it’s set al.

Writing down the aperture of every shot in a notebook is a pain. What else can the NEX-7 user do? A few ways to cope:

• Carry an erasable slate. Write the lens ID and f-stop on it whenever you change either. Take a picture of the slate.
• Live with the purple corners. Consider them a camera fingerprint and celebrate them in the same way that some photographers do the edges of Polaroid 55P/N negatives. This is my least favorite option.
• When you get a keeper, run Cornerfix against it with profiles for all the apertures of that lens. Pick the right one by eye.
• Use only lenses that don’t shade the corners much. The Leica 50mm f/1.4 Summilux is a great lens, and has only mildly magenta corners at f/5.6 or smaller apertures. Anything longer should be fine.
• As a special case of the above, don’t use wide angle M-mount lenses; use SLR WA lenses instead. Their greater flange distance (to stay out of the way of the swinging mirror) makes them less susceptible to purple corners. These lenses are usually bigger and heavier, though, and changing the apertures on G-series Nikkors is a problem. One exceptionally small and light (and sharp) SLR WA (though it’s not a WA on the NEX-7) is the Nikon 35mm f/2 D.
• Make only black and white images with lenses that have offensively purple corners.
• Don’t use apertures wider than f/5.6, so you only have to calibrate the lens at one f-stop. Most WA lenses aren’t their sharpest at f/8 and smaller (numerically larger), so that plan could limit you to one aperture setting.
• Get an NEX-5 or 5n; they don’t have the problem to a great degree.

I‘ve been using the Really Right Stuff NEX-7 baseplate for a few days. I can recommend it, with one caveat. The first thing you should ask yourself is, “Do I really want to use this camera on a tripod?” The answer could well be no; one of the great arguments for the camera is its portability, and carrying a tripod, even a carbon fiber travel tripod, is going to slow you down. Many NEX-7 owners will take one of their other cameras along if they’re going to use a tripod, and that could be a wise decision, especially if the other camera is a D3x, 1Ds,or 1Dx.

If you’re going to use the NEX-7 on a tripod, you’re probably going to want a baseplate, and the RRS baseplate is a good one. It’s nicely machined, and is no wider than the bottom of the camera except for the ears that engage an  Arca-Swiss-style clamp. That makes it light and as unobtrusive as it can be and still do its job. There’s a machined recess in the bottom that makes it so the head of the screw that goes into the camera doesn’t stick out; you can set the camera down on the plate and it will be stable, especially if you’re not using the safety stop.

The only serious awkwardness in handling the camera with the plate attached is that you can’t flip up the LCD screen from the bottom; you need to find the lower left corner with your finger. It’s pretty easy to get used to this.

I also ordered the L-plate, which makes it easy to use the camera on a tripod both normally, in landscape mode, and turned 90 degrees for verticals. I am normally a fan of L-plates, but I think in this case it makes the camera too bulky. You may feel differently.

In this post, I compare the Sony NEX-7 with the Nikon D3s operated in full-frame mode, with the Sony images resized to the Nikon’s 12 megapixels. I used the Nikkor 35mm f/2 D on the NEX-7, and the Nikkor 50mm f/1.4 G on the D3s, providing approximately the same angle of view. The NEX-7 did well against the Nikon when the Nikon was operated in DX mode and the Sony images were downsized to the 5 megapixels of that mode. This test will be harder on the NEX-7, because the Nikon gets to use its entire sensor, and the Sony images won’t be downsized as much. Both lenses were set to f/5.6.

All images were processed in Lightroom 3.6 to remove most visible noise, with the Nikon image settings limited by a desire to retain the greatest amount of image detail consistent with low noise. The Sony images were resized down to 4256×2832 using Perfect Resize with the default settings. Presented here are crops 360 pixels wide, magnified 2x using nearest neighbor.

At ISO 3200, the Nikon image required very little de-noising:

Also at ISO 3200, the NEX-7 image is close in quality, but not quite as sharp. Some processing artifacts are visible around the red lettering.

At ISO 6400, here’s what the D3s did:

At ISO 6400, the NEX-7 is performing credibly, but it not as sharp and is noisier:

The Nikon turns in a pretty amazing performance at ISO 12800:

While the detail on the NEX-7 falls apart and the color saturation suffers at the Lightroom noise settings required to control the color noise.

In the sixties, there used to be a saying in sports car racing circles: “You can’t beat cubic inches.” The photographic equivalent seems to be: “You can’t beat sensor area.” Still, the Sony didn’t do badly, and this set of posts has demonstrated that you can effectively trade resolution for noise in post processing.

In this post, I extend the testing done at ISO 3200 to 6400 and 12800. Same deal as in the previous posts, but I’ve dropped the NEX-5. Cameras: Sony NEX-7 and Nikon D3s. The Nikon was set to DX mode, giving it the same sensor size as the 24 megapixel Sony, but with only a little over 5 million big pixels. Same lens on both cameras: the Nikkor 35mm f/2 D (by the way, this is one sharp lens; I did a comparison with the Sony/Zeiss 24mm, and it was substantially crisper at f/5.6 for subjects a few feet away). Same aperture: f/5.6.

Here’s the overall image from the NEX-7 at ISO 6400:

All images were processed in Lightroom 3.6 to remove most visible noise, with the Nikon image settings limited by a desire to retain the greatest amount of image detail consistent with low noise. The Sony images were resized down to 2784×1848 using Perfect Resize with the default settings. What is presented here are crops 360 pixels wide, magnified 2x using nearest neighbor.

The NEX-7 image at 6400:

The D3s image at 6400:

The NEX-7 image at 12800 (note that there are a couple of cyan spots I couldn’t get rid of even with LR’s color noise control far enough to the right that the colors began to suffer):

The D3s image at 12800:

The improvement in quality of the NEX-7 over the D3s images is not as striking as it was in the ISO 3200 comparisons. On the other hand, the Sony images look better to me, and no one would say they are  worse, which is quite an achievement against a low-light champion like the D3s.

Next: the gloves come off, and we compare NEX-7 photographs to full frame images from the D3s.

Why does the technique of the previous post work? I think it may be a combination of the following:

• I didn’t use liveview to focus the D3s reference image, so it could be slightly less well focused than the Sony images. I will use liveview in future testing, although it increases noise by heating the sensor. Should I make the reference images by focusing with liveview, then turning it off, letting the sensor cool down, then making the exposure? Or is that tilting the playing field too much?  [Addendum: I made some test images, and that's not it; the autofocus pictures are as sharp as ones focused manually with the aid of liveview.]
• The antialiasing filter in the D3s blurs more (measured in microns, not pixels) than the AA filter in the Sony’s, because the pixel pitch is larger.
• The processing done by Perfect Resize artificially sharpens the image. If that’s the case, does that processing adversely affect some subject matter? It’s not just the usual sharpening, because I can’t duplicate it with the Nikon images. It will take some testing to find out.

I wonder how far I can push the ISO and still get high-quality 5 megapixel images? I wonder what would happen if I resized the NEX-7 images to 12 megapixels and compared them with full frame D3s images? More to come.

I have exciting news. At least, it’s exciting to me. Your reaction may be, “Kasson, you really need to get out more.” Anyway, after many unsuccessful attempts, detailed in the previous posts, to tame the NEX-7 high-ISO noise by reducing the resolution of the image, I finally found something that works.

Here’s the recipe. Go into Lightroom or your favorite raw converter (I’ve only used Lightroom, but the technique should work in any other raw converter) and open up the noise controls. Get rid of all, or almost all, the visable noise. Be aggressive. Let the detail suffer a bit. Then resize the image downwards. I used Perfect Resize with the default control settings.

Using this approach, I resized NEX-5 and -7 images made at ISO 3200 from their original sizes to the 2784 x 1848 DX resolution of the reference Nikon D3s, and got lower noise and better details!

The crop of the NEX-7 image looks like this:

The crop of the NEX-5 image looks like this:

The crop of the reference D3s image. very lightly touched up with Lightroom noise reduction, because it’s so clean to begin with:

In search of optimum tradeoff of noise and resolution in a 5 megapixel resize of NEX-5 and NEX-7 images, I tried a series of averaging operations before the resize. The one that worked best for the NEX-7 test image was a 2-pixel box blur in Photoshop followed by a resize in Perfect Resize using the default parameters. Even so, the results were inferior to the reference D3s image — both noisier and not as sharp.

The crop of the NEX-7 image looks like this:

The crop of the D3s image looks like this:

Included for completeness is this crop of the NEX-5 image, although the 2-pixel box blur is too broad for the 3:1 downres: