Graflex RH10 holder - a dog, or me stupid? :)

[eumenius]

Hello friends,

two well-worn Graflex RH10 120 roll film holders came as a part of my new Century Graphic kit including Rodenstock Heligon 95/2.8. I have spent two hours cleaning, adjusting and calibrating the Kalart rangefinder and the infinity setting (using a good loupe and Moscow State University tall building as a target), checking also the registration of film plane (a strip of ground glass on holder's rollers from inside) and the GG plane. Well, the first shot roll of film has seriously disappointed me - the sharpness was uneven all over the frames, being better on smaller apertures, and there were frames shot on f/8 with no sharp areas detectable Are RH10 holders THIS bad in terms of film flatness, in spite of the rollers around the film gate, or maybe the film loaded from the +4C fridge without acclimatisation has fooled me, curling uncontrollably? I am planning to get Mamiya RB backs anyway, when the money would be more plentiful, but I am puzzled now I have re-set the infinity on camera from scratch, and I have also bent the spring on the back's lid, keeping its guts well-pressed against the base - didn't shoot with it yet, though. What is your opinion on the true reasons for my unsharp negs?

Cheers,
Zhenya

 

[Dan Fromm]

Zhenya, adjusting a Kalart is an iterative process. You must, if you use the simplified method that I think is posted on www.graflex.org, adjust at 15' and 6' and redjust as necessary. A well-adjusted Kalart should be dead on from about 4' out, useless inside 4' or so.

Since you're worried about your roll holders etc., shoot a well-thawed roll with careful focusing on the ground glass. That will eliminate possible RF adjustment or (horrors!) use errors.

Cheers,

Dan

 

[eumenius]

Yes Dan, I have done the adjustment in the iterative way, and now it is dead on on all three checkpoints. My specimen appears to be temperature-sensitive - I had to align its horizontal beam twice, through a funny hole in side bracket, covered by a pierced piece of rubber from inside

I am already thawing the next roll, and I will be using the GG focusing for each shot - but my first negs were unsharp in a very characteristic way, when nothing is in focus - and especially the ones shot on infinity, when the film buckled up in the film's window going past the focal distance, so a half of my negative was reasonably sharp, and the next half was all blurred. Fortunately, my only previous experience with such things from roll holders was related to the old Patent-Rollex for my Voigtlander Avus, that simply refused to keep film in a registration position

Regards,
Zhenya

Zhenya, adjusting a Kalart is an iterative process. You must, if you use the simplified method that I think is posted on www.graflex.org, adjust at 15' and 6' and redjust as necessary. A well-adjusted Kalart should be dead on from about 4' out, useless inside 4' or so.

Since you're worried about your roll holders etc., shoot a well-thawed roll with careful focusing on the ground glass. That will eliminate possible RF adjustment or (horrors!) use errors.

Cheers,

Dan

 

[glbeas]

Are the tensioning tabs working properly to keep the film tight between the roll and the takeup spool?

 

[eumenius]

What tabs do you mean, the flat springs pushing against the rolls from their underside? I have bent these a bit upwards, too - just as a precautionary measure. I would shoot a roll tomorrow with it to see if it makes any effect.

And the RH10 is also squeaking creepy - the shell against the inner mechanism, he-he

Are the tensioning tabs working properly to keep the film tight between the roll and the takeup spool?

 

[glbeas]

Yes, those. It may make a lot of difference. When you took the last roll out did you notice if the paper was wound tight or did you have to snug it up some before taping it shut. My Bronica has smaller springs to tension the roll and when they get sprung the roll winds loose and tends to get fogging along the edges from light leaking in. It doesn't affect the focus much on these backs though.

 

[ricksplace]

I have a century graphic and I use Mamiya and Graflex backs on it. Both types of backs work equally well. If you have the back attached without the dark slide in, and you open the camera, the suction when you pull out the lens can pull the film towards the lens away from the film plane. Pull the lens out slowly to prevent this, or attach the film back once the camera is opened. If you focus on the GG and still get blurry images, it might be your lens. Is the lens tight on the lens board? Is the lens board tight in its mount? Any vibration when the shutter is fired will cause blurring.

 

[Sparky]

From what I'd read on Robert Monaghan's old website - it seemed that several people believed the singer/graflex holders to offer superior flatness and accuracy than the horseman, calumet, linhof, etc etc...