hkr4627@acf4.UUCP (Hedley K. J. Rainnie) (04/18/85)
Anyone know why non-professional cameras offer a diminished view of the picture than will appear on the negative, sometimes as little as 90% of the negative area? Why do only professional camera's offer a relatively full view of the picture area? Canon AE-1 finder area 91% x 92% of film area Nikon FE finder area 93% x 92% of film area Canon F-1 finder area 96% x 98% of film area Nikon F3 finder area 98% x 99% of film area (source: MODERN PHOTOGRAPHY product reviews) -r-
rfg@hound.UUCP (R.GRANTGES) (04/19/85)
I read the reason once, but think I have forgotten. This may be it: Most users, especially non-professional ones, are going for slides in their original cardboard mounts. These mounts typically expose only about as much of the whole frame as the non-professional cameras let you see. The pro needs to see the full frame, the non-pro doesn't (supposedly). -- "It's the thought, if any, that counts!" Dick Grantges hound!rfg
dsg@mhuxi.UUCP (GREEN) (04/19/85)
[]
Less than 5% of all photofinishing is "chrome" or slides. It would
make little sense for camera designers to engineer their product for
that small of a market segment.
The real reason why viewfinders show less than 100% percent of
the actual image is simply to compensate for all areas where
screw-ups may occur, in order of importance:
1. Chopping off heads ( even with slrs it is quite common ),
2. Poor placement of film in enlarger negative holders,
3. Film shrinkage/expansion before, during and after processing,
4. Poor manufacturing tolerances in the cameras themselves,
5. Some ( not much ) consideration for slide users,
6. The assumption that a real pro who is concerned about 1 or
2% of the total image area would probably use a view
camera anyway.
Just a side note - real photographers ( "pros" ) usually buy a few
expensive cameras and then worry about things like fickle models,
paying bills, getting assignments, image quality and deadlines.
Pros use Nikons and Hasselblads because they are reliable; not
for "fancy" features. They also use custom labs for developing
because turnaround time and quality is critical. The monthly
rent and model expenses ( and other overhead ) far outways the cost
of cameras and photofinishing.jam@ho95b.UUCP (Joe Malecki) (04/20/85)
>Less than 5% of all photofinishing is "chrome" or slides.
However, an interesting statistic (which has nothing to do with viewfinder
areas) is that approximately 80% of all professional, commercial photography
are transparencies.
Photofinishing includes the Instamatic and Disc crowds, undoubtedly an
extremely large portion of that market.
--
Joe Malecki
AT&T Bell Laboratories
Room 4K-223
Holmdel, NJ 07733
(201) 949-4847
{allegra, cbosgd, ihnp4}!ho95b!jammike@asgb.UUCP (Mike Rosenlof) (04/22/85)
<> > Anyone know why non-professional cameras offer a diminished view of the > picture than will appear on the negative, sometimes as little as 90% of > the negative area? Why do only professional camera's offer a relatively > full view of the picture area? > > Canon AE-1 finder area 91% x 92% of film area > Nikon FE finder area 93% x 92% of film area > Canon F-1 finder area 96% x 98% of film area > Nikon F3 finder area 98% x 99% of film area > There are two main reasons, the first is size. A screen which covers 100% of the negative is bigger than one which covers only 90%. In the examples, the F-1 and F3 are both larger than the AE-1 and FE. Larger also means heavier which is a bigerg disadvantage in the "mass marker" cameras than the "pro" models. Correct me if I'm wrong, but I'd bet that the Pantax LX - definitely a professional camera - doesn't cover 100% of the field of view, mostly because of its size. The second reason is manufacturing tolerances. A slightly diminished view allows a little more slop in aligning the viewing system. By easing the tolerances, the price can be brought down. Mike Rosenlof ihnp4!sabre!\ hplabs!sdcrdcf!-bmcg!asgb!mike { ihnp4, ucbvax, allegra }!sdcsvax!/ Burroughs Advanced Systems Group Boulder, Colorado
josephs@ttidcb.UUCP (Bill Josephs) (04/22/85)
There's another much more important explanation of why cameras
have different view areas than film areas: different focal length
lens have different light paths in the film chamber and the rapid
return mirror consequently intercepts this light path differently. It
is difficult to describe, but consider the cross section of the film
chamber with the lens on the right, the film plane on the left and the
camera as a box in front of the film plane. The easiest mirror to
design is then a diagonal from the upper left towards the lower right
with a minimum length equal to the size of the film (since when the
mirror is flipped up, it must at least cover the ground glass). The
longer the mirror, the deeper must be the camer body. The shorter the
mirror, the more likely some of the rays from long focal length lens
will "escape" below the edge of the mirror. Also, the longer the mir-
ror, the more force it takes to flip it up and the harder it becomes
to absorb all that torque and stop it smoothly and quietly.
I hope this makes sense....
Bill Josephs
Citicorp/TTI