I know that's true, but I'm saying they have all that image circle to
play with, and it looks to me that the mirror is the same size, so why
not do a little playing around with the margin like I mentioned?
Peter J. Alling wrote:
The *ist-D viewfinder is designed from the ground up to show the APS
sized image. It's not just a masked down finder such as you'll find in
Nikon and Canon mid to low end offerings. If you ever compared the two
side by side you would see the difference. Based on that alone Pentax
should sell a whole lot of them.
Gonz wrote:
Since the *istD is using only a portion of the full 35mm frame, I
wonder why they dont do something like engrave a tiny grove showing
where 100% is on the viewfinder, but cover something like 110% of the
frame, so you can see where you are cutting if off in context. I
don't know that the issues around alignment would be, probably the
same as you mentioned. But maybe if they had a simple means of
alignment with this technique when it was built using some type of
fixture, it might not be so bad? I'm just musing here...
rg
John Francis wrote:
I don't quite buy that. What determines the size of the viewfinder
image is the
size of the frame the screen sits in (as long as we are talking +/- a
millimeter). Make that frame a little bit larger and you have a 100%
viewfinder. Of course, all elements that attach to the mirror box
have to be
'accurate' but I don't see why that would be so difficult here.
Ah, but that's precisely what *is* difficult. It's not just the size
of the
viewfinder - it's position the boundaries accurately.
It's easy(-ish) to make a 95% viewfinder, because you only have to
position the
viewfinder region to +/- one mm. Make the frame a little bit larger,
though,
and you don't have a 100% viewfinder; if you're off by that same 1mm
you might
have a viewfinder that showed 97.5% of the image, cropping off 2.5%
on the left,
and showing an extra 2.5% on the right that wasn't part of the true
image area.
This would be bad. If you can see it through the viewfinder, people
expect it to
show up on the image. The extra 5% allows for a certain amount of
inaccuracy.
To get a true 100% viewfinder (no more, no less) would require at
least an order
of magnitude more accuracy - everything would have to be aligned to a
precision
of 0.1mm or better. That would require a camera considerably more
rigid, and
manufactured to much closer tolerances, than consumer-level prices
can support.
