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View Full Version : Some thoughts on viewfinder problems


Charles D. Orze
04-02-2005, 15:10
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.

Doug
04-02-2005, 18:25
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
04-03-2005, 11:16
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.

Best,

Charlie

Doug
04-03-2005, 15:39
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
04-03-2005, 16:35
Hi Doug,

The R D1 does have a grid overlay for the LCD--problem is you can only access it after the shot has been made.

Best,

Charlie