First photos with the Crown Graphic and 6x9 back - Focus problems?

[Keith]

Your reference to a Holden Ute.....

As I understand it a Holden is an Australian GM car/truck. A Ute is a utility vehicle. Ford in Australia was first to rise to the request from farmers wives for a vehicle that could take produce and goods to market during the week, and yet be presentable to take the family to church on the weekend. I think it was 1934 when Ford introduced the Ford Coupe Utility. Essentially a Coupe body which could seat five, with a utility bed (like a pickup) faired into the body for market duty.

The "ute" utility concept survives today if I am correct.

It does indeed ... I drive a six year old Ford Falcon ute. It also runs a dedicated LPG engine! (LPG currently 75 cents per litre)

 

[kuzano]

Hmmmm interesting...

Hmmmm interesting...

This tells me the ground glass in the Graflok is sitting about 0.3mm too far back. Cheers!

Not sure how much effect .3 mm will make on focus, but it can be tested. If you conclude that the GG is back from the lens .3mm, more than the film holder, you can make a .3mm mask around the camera mating surface of a film holder. Insert a loaded holder in the camera and shoot some test shots. Perhaps a formal focus target. A couple of shots without the shimmed holder and a couple (Or a few) with the shimmed holder.

You will have your answer.

Such fun these old camera's... simple. Not a chance.

 

[Johnmcd]

Hey Chris if you can email that manual to me that would be great. I think you have my email from a previous film purchase.

Cheers John

 

[sevo]

This tells me the ground glass in the Graflok is sitting about 0.3mm too far back.

Maybe. A fresnel in front of the ground glass will alter the focal plane - so the ground glass is offset to compensate that. To know whether these 0.3mm are the proper displacement, we'd really have to know its focal length and the distance between its nodal point and the ground glass, and calculate the focal plane displacement from them.

Personally, I think that 0.3mm are wrong. As described, it would be a offset into the wrong direction, and about a magnitude too small - in the cameras where I recalibrated front fresnel arrangements, I came up with forward offsets around 2mm. But the Graphic (other than German view cameras) was designed around a front-mounted fresnel, so that the needed displacement may already have been considered in the back design.

 

[graywolf]

In fact Pacemaker Graphics are set up with the fresnel from the factory. If it is not there, then one has to fabricate a spacer to put the ground glass at the film plane.

Properly set up Graphics make fine images whether focused from the ground glass, the focus scale, or the rangefinder. But it all starts with a properly set up ground glass. Once that is properly set up you then set up the scale focusing, and then the rangefinder focusing. Those set ups hold nicely, and you should not have a problem again unless someone gets in there and "fixes it".

Once the GG is set up the only other thing that is not pretty obvious is that infinity is not with the rack all the way back. Because the camera is wood, and thus has a tendency to swell and shrink a bit, the camera is properly set up with infinity set with the rack about 1/8" (3mm) forward. That also allows for the adjustment hat the RF needs.

There is nothing really difficult to setting up the camera, it is just that so many were "fixed" by someone without a clue.

Once you know which way the GG/Fresnel sandwich goes in, and about the 1/8" of slack, everything else usually falls into place unless there is actual damage.

Most plastic "Graphic" film holders will be in close enough tolerance for commercial work. Old wood film holders may not. "Graflex" holders will not work correctly at all, they will not seat properly.

I have read that the factory had focusing target a 100' and 6' to set up the camera. The Kalart (sidemount) RF also needed a target at 15' to verify the setup.

There is more info out there & more people using press cameras than there was when I set up my webpages about them. Back then there was only graflex.org and a couple of collector sites, and nothing about using a press camera as they were originally intended to be used, as most people that bought them wanted a cheap view camera.

Yours looks like a nice clean camera. I hope you get it working and have a lot of fun using it.

 

[sevo]

Once the GG is set up the only other thing that is not pretty obvious is that infinity is not with the rack all the way back. Because the camera is wood, and thus has a tendency to swell and shrink a bit, the camera is properly set up with infinity set with the rack about 1/8" (3mm) forward.

I don't think it is that. The tropical wood from which Graflex bodies were made is quite moisture proof (I've seen many with leather eaten off by mould and metal parts badly corroded, where the bare body still was restorable). It even is much less vulnerable to temperature drift than metal constructions (tropical and polar expedition cameras remained mostly wood, with no leather and minimized metal, long after metal cameras had become standard).

If there is a factory designed 3mm rearward slack, that will simply be the space needed to accommodate a no-fresnel or rear-fresnel groundglass.

 

[graywolf]

It is for sure needed with the side mount RF, it does not start to register until the lens is racked out a bit. I do not know about the top mount RF (I have never worked on one). But the instructions did say it was for the wood expanding and contracting.

The wood is mahogany (South American, I believe, not African), by the way. Fairly dimensionally stable, but not as stable as maple (for instance).

 

[Johnmcd]

Thanks again to all that have added to the discussion. Might get a chance to take another roll this weekend and check the results. Fingers crossed.

John

 

[Johnmcd]

Update

Update

By using the manual (thanks Chris) I was able to re-adjust the RF to infinity. Not an easy task as the act of tightening the locking screw of the RF mirror always twisted the mirror away from the proper position. Fiendishly frustrating. Anyway with more luck than anything I got it set.

Took a quick walk down to the bay and shot 8 focused images 🙂 All at F16 and 1/250th. HP5 in Rodinal.

Thanks to all those that helped. Much appreciated.

 

[graywolf]

Nice!

Glad you got it all sorted out.