Fuji GSW690II - vignetting / corner sharpness / film choice

Hi

 

I recently purchased a secondhand Fuji GSW690II (65mm lens, late 80's vintage).

 

I bought the camera to shoot an urban landscape project. Initial tests on transparency

showed considerably vignetting and corner softness at f5.6, but these problems

seemed mostly resolved from f8 onwards.

 

Satisfied with my initial tests, I am now shooting the project on colour negative film,

with the camera on a tripod at apertures of f16 and f22. When printing in the

darkroom I've noticed that I'm still getting some vignetting. For a typical enlarger

exposure of 10 seconds I have to dodge the corners for about 2 seconds to even out

the image. Is this normal? (This is not an enlarger problem - I'm using a 5x4 enlarger

with 150mm lens - and if I scrutinize my original transparency test I can see slight

vignetting at all apertures).

 

I'm also noticing a slight image softness in just the extreme bottom left hand corner

of all my images (f16, f22). Any explanation?

 

Final question is about film choice. I've been using Porta 160VC, rated at 100, pushed

half a stop, and printed on Kodak Endura Supra (matt finish). My subject is urban

landscapes - concrete, faded paint, rust - all photographed under an overcast sky.

Results are ok, but maybe lacking a little 'snap'. I plan to test Portra 400UC and Reala

for this subject matter. Any preferences?

 

Thanks

 

Elliot

Elliot, just some thoughts on one part. If you're seeing image softness in the lower left corner, there are two possibilities to consider:

 

1) The lens might not be sitting parallel to the camera. That could mean the upper right corner of the lens support is slightly out of position. Check the camera for any signs of impact damage.

 

2) Possibly the film isn't being held flat against the gate. I would check the pressure plate and see if the pressure plate springs back smoothly when you push it down on different parts of the pressure plate, including the corners.

 

One way to check if it's the lens or the pressure plate is the newspaper method using a piece of ground glass and a loupe (or a camera lens). If you don't have ground glass, frosted tape across the film gate will do.

 

Tape a newspaper to the wall. Put the camera on a tripod parallel to the wall and focus on the newspaper. Six or eight feet should be sufficient. Make sure the newspaper is well-lit.

 

Open the aperture to the widest point, set the shutter to "B" and lock it open with a cable release.

 

Using the loupe (or peering through the back of a camera lens), carefully check all four corners.

UC 400 or Reala are *the* choices for your subject matter. Both will work fine with Endura with Reala being ideal for sunny conditions and UC being ideal for everything else.

Elliot, after giving this a bit more thought, I supposed you'll need to stop the lens down to f/8 when checking corner sharpness. In that case, you'll want to use some type of hood (sort of like what they use for view cameras) when peering through the back of the camera.

nt

I have this camera, but bought brand new in 2002. I have not noticed any vignetting at F5.6 at all. In fact I was amazed the first time I saw the photos.

 

Assuming that the lens has not been improved upon since the late 80's, then I think you should take the camera in for a check-up.

 

Good luck! :-)

I have this same camera and have not noticed any vignetting using color negative film

and scanning the film. In fact, I am very surprised.

 

I also have a GW690III (90mm) and it has significant vignetting that is very obvious at

all apertures.

I have both the GW690III and GSW690III and have never seen any vignetting at any aperature. Both of my cameras were purchased new.

I am in exactly the same position as Robert.

Many thanks for the replies.

 

I'm about to run tests with Reala and 400UC.

 

After a further session in the darkroom I'm less sure that I have a problem with the

focus in one of the corners.

 

Vignetting, however, is definitely an issue. It's minor (less than a third of a stop) at all

apertures except wide open (where it's about two thirds of a stop). But it's there and

needs to be corrected via a quick

dodge with every print I make.

 

I've read that the lens design of the Fuji rangefinders did not change through the

different

versions of the camera . But now I'm not so sure. How does anyone know this?

 

If the third and final version of this camera is better in terms of lens performance,

then I'll eventually sell mine and search for a newer version.

 

For now I'll stick with what I've got and complete my project (with some minimal

darkroom manipulation).

 

A centre spot filter would be preferable, but I assume that there isn't one available

for the Fuji rangefinders. Why does these filters seem more popular with large

format

cameras? Are large format cameras more inclined to vignetting, or are large

format photographers more fussy?

 

(My normal camera is a Mamiya 645AF, and I've never experienced a hint of

vignetting with any of its lenses (55mm, 80mm, 150mm).)

 

On the plus side my GSW690II is very sharp, exhibits no barrel distortion, and can be

handheld at very slow shutter speeds.

 

Thanks

 

Elliot

>>Why does these filters seem more popular with large format cameras? Are large format cameras more inclined to vignetting, or are large format photographers more fussy?<<

 

 

Not more inclined to vignetting. Jut more fussy; and they use a tripod most of the time, so slower shutter speeds is not a problem.

 

You wouldn't be using large format unless you want the absolute quality anyway.