View Full Version : Some thoughts on viewfinder problems
Charles D. Orze
Having read various observations about viewfinder patch and frameline skew I decided to take a shot of my back door. The result was about a degree and a half skew down to the right! I took a few more shots of rectangular objects. Same! So I got the tripod out and did some tests. First, under most viewing angles my viewfinder patch appears slightly rotated with respect to the frame lines. I observed closely that it in fact appears slightly non-rectangular and larger vertically on the right side. On the tripod, facing a bookcase with a 50mm Nokton, I shot a series of frames lined up respectively on the top line, left line, and right line. What I discovered is that if I tried to use the left hand line of the frame the result is a very slight skew. If I align carefully on the top or the right side the camera is dead on! What I suggest is the following: First, the parallax correction mechanism and the optics somehow distort the image slightly, and perhaps has something to do with the skew. Second, the handheld right-down skew is none other than my old habit of moving the camera when pressing the shutter. This is not to say that some cameras aren't significantly mis-aligned, but before shipping it back check it on a tripod. I've moved my soft release to the R D1. By the way, focus on the camera is spot on at f1.5 close up.
Yes, it's not uncommon for the camera to move as the shutter button is pressed. Something to try to avoid. Or maybe an air release operated by mouth? :)
Charles D. Orze
Thanks Doug! Well, it is quite clear that the sensor is properly squared to the camera body. There looks to be a tiny bit of skew, most noticable on the 28mm framelines. I took a further series of handheld shots on various square objects. It is no easy feat to get things to come out precisely, and since my "standard" lens is actually a 35 and my preferred lens an Ultron 28 one must be very careful indeed. This is what tripods are for.
Some people like bubble levels to aid keeping the camera level. I haven't tried one, and I wonder if I'd get dizzy glancing back and forth between the constantly jiggling scene and the constantly moving bubble! Maybe these are best on a tripod? OTOH, CameraQuest sells a sophisticated Voigtlander bubble level intended to sit next to an accessory viewfinder on a double-shoe adaptor, and it's arranged in such a way the level is visible in peripheral vision while looking through the viewfinder. Why don't they put bubble levels INside the viewfinder? Or grid lines?
My favorite SLR has a "grid" focusing screen with etched vertical and horizontal lines that I find very useful even hand-held, to align with elements in the scene. When I got a second body I immediately put a similar grid screen in it too. For that matter, the accessory handgrip for the camera has a bubble level on the top.
And the 21mm accessory viewfinder for the Contax G system has a central cross-hair, like a rifle scope, which helps with alignment too. An idea other viewfinder makers could copy!
Charles D. Orze
The R D1 does have a grid overlay for the LCD--problem is you can only access it after the shot has been made.
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