Questions from a Speed Graphic Newbie

[jbenedict]

If you folks don't mind another question...

The back of the camera has slide-locks that slide inward, presumably to lock a back against the camera. Yet these locks are not positioned at the right height to lock either the Graflock back or my film holders. So what in the heck fits in there that makes these slides useful?

It is also possible to lock in Grafmatic holders. When I was doing a lot of handheld 4x5 with my Crown Graphic, I usually locked in my Grafmatic so I wouldn't pull it out of position when I changed septums.

[Fred Haeseker]

Hi Bravin: About the sliders on the camera back. Only the Graflex and Graflok backs had sliders. The Graflex backs need special film holders that have a groove running down the middle of the sides.
Your camera may have the Graflex back, on which the sliders are oriented differently than on the Graflok back. It's very confusing, but Jo Lommen's press-camera website has an excellent explanation with good illustrations:
http://www.xs4all.nl/~lommen9/

[Bravin Neff]

Hi Bravin: About the sliders on the camera back. Only the Graflex and Graflok backs had sliders. The Graflex backs need special film holders that have a groove running down the middle of the sides.
Your camera may have the Graflex back, on which the sliders are oriented differently than on the Graflok back. It's very confusing, but Jo Lommen's press-camera website has an excellent explanation with good illustrations:
http://www.xs4all.nl/~lommen9/

That link is excellent. Thank you for the information!

Regards,
Bravin Neff

[Jim Jones]

The old ASA diminsion from the face of a 4x5 film holder to the septum between the halves is .0197" +/- .007". The channel for the film is a minimum of .012". Film is typically about .007" thick, although I've seen it from .004" to .01". Sloppy tolerances to a machinist, eh?

Without a fresnel, the distance from the front of the flange to the ground glass should equal the corresponding distance to the film in its holder. However, with a fresnel between ground glass and lens, the optical distance must be the same, but the physical distance will be different, depending on the thickness of the fresnel and its index of refraction. You don't have to be an alchemist or a witch doctor for large format photography, but it probably helps.

[Glenn Thoreson]

The Graflok slides are only there for holding accessories, i.e. roll film holders, etc. They aren't made to hold sheet film holders, which slide under the focus panel. Make sure your focus panel is installed correctly. The spring arms hook under a retainer on the sides of the back opening. They should just snap into place as you slide the focus panel into the back. To remove the focus panel, press down on both arms and slide it to the right. Most accessory holders, etc. require that the panel be removed and the accessory held on by the slides. Some accessory holders, such as the Polaroid 545 will work as a slide in or clip on, either way. Enjoy!
Another thought: I don't think you will find a fresnel on the focus panel for the Graflex back. I've never run across such a thing, anyhoo.