Fresnel on Crown Graphic ?

[BradS]

So, my 'new' crown graphic arrived today. It has a Fresnel lens. I took the whole business apart to clean it and now, I forgot which way the ridges on the Fresnel lens go...anybody know?

Do the ridges go toward the lens or toward the GG? (I'm assuming that the fresnel goes closer to the lens and the GG goes on top, closer to...me!)

[Dave Parker]

Should go fresnel first, concentric circles facing out, then the ground glass over top of that, that is the way that all of them I have had, were put together. You might try it both ways to see which gives you the best image...

Dave

[BradS]

Thanks Dave. I knew that you'd know....:)

Brad.

[venchka]

Should go fresnel first, concentric circles facing out, then the ground glass over top of that, that is the way that all of them I have had, were put together. You might try it both ways to see which gives you the best image...

Dave

That is how my Speed Graphic was configured when I bought it from the man who bought it new in 1953. I asked the same question here and got the same answer.

Enjoy!

[BrianShaw]

The way Dave described is how WD Service (remember them?) showed me as they did a fresnel/GG installation on my camera while I watched. It is also doucmented in the official repair manuals, which can be found on the internet.

EDIT: the one thing Dave didn't explicitly mention... the ground aprt of the glass faces the bumpy side of the fresnel.

[Dave Parker]

The way Dave described is how WD Service (remember them?) showed me as they did a fresnel/GG installation on my camera while I watched. It is also doucmented in the official repair manuals, which can be found on the internet.

EDIT: the one thing Dave didn't explicitly mention... the ground aprt of the glass faces the bumpy side of the fresnel.

Sorry Brian,

Knowing Brad's experience level, I figured he knew that part already!

For anyone else's benefit that may not know, when you place the ground glass in the camera, the ground side, faces the lens end of the camera!

:D

Dave

[Turner Reich]

Busch C, ground glass, a Satin Snow, ground side facing the lens, a Fresnel on top of the ground glass, the smooth unground side of the ground glass, the ridges of the Fresnel against the smooth side of the ground glass.

That's how mine is installed, doesn't the Fresnel magnify the ground glass or is this wrong and the Fresnel should be the first piece from the lens and then the gg. Or do I really need one with the Satin Snow?

If I were to put the Fresnel first from the lens wouldn't that change the position of the gg in regard to the t-depth?

tr on a confused day in fog.

[BradS]

Well, I got it all back together...I think I bought this from the adult children of the man who first purchased it new in ca. 1952...
I set the thing on a tripod and focussed with the rangefinder, checked focus on the GG and...HOLY CRAP! It's in focus! The RF is not completely useless on this one as it was on my first. I guess I may find a use for that roll film back yet.

Now, If I could just get a few minutes away from the day job....(sigh).

Brad.

[BrianShaw]

Now, If I could just get a few minutes away from the day job....(sigh).

I feel your pain!

[BrianShaw]

If I were to put the Fresnel first from the lens wouldn't that change the position of the gg in regard to the t-depth?

The procedure mentioned above is ONLY for Graphics that were originally provided with factory-installed fresnel.

I believe you are correct that putting a fresnel between the GG and lens of a camera that was not originally designed to have a fresnel between the GG and lens would cause cause your t-depth to be wrong.

[Dave Parker]

Busch C, ground glass, a Satin Snow, ground side facing the lens, a Fresnel on top of the ground glass, the smooth unground side of the ground glass, the ridges of the Fresnel against the smooth side of the ground glass.

That's how mine is installed, doesn't the Fresnel magnify the ground glass or is this wrong and the Fresnel should be the first piece from the lens and then the gg. Or do I really need one with the Satin Snow?

If I were to put the Fresnel first from the lens wouldn't that change the position of the gg in regard to the t-depth?

tr on a confused day in fog.

Turner,

Your right on the money...the outlined procedure was for the Graphic cameras, with the factory installed Fresnel.



Dave

[Turner Reich]

Thanks to the op and all who again help me sort this out. I am writing it in my notebook. The Satin Snow ground glasses are excellent, I got a 2x3 Fresnel in a package with 4x5 and 5x7. It appears to work fine, nice and bright so I won't be taking it out.

regards tr