Replace 4x5 focusing screen. Help?

[StianSvendsen]

Hi guys!
I recently got a 4x5 Graflex Crown Graphic.
I love this thing, so compact yet robust, and
the old schneider lens is shockingly good.

The camera and lens is mint, not even signs of use on this thing.
Pretty weird for a 70 year old press camera.

The screen on the other hand, I have no idea what happened
to it based on the condition of everything else.

It's got scratches, it's very dark, it seems faded, and someone drew a
referance frame on the screen. I really wanna swap this out with a new one.

I'm looking for something brighter, I prefer a blank screen with no references.
A centered cross like my Hasselblad has would be fine, but brightness really is
my main priority.

- Screen suggestions?
- Will certain screens affect focusing, maybe making it inaccurate?
- Other things I should be aware of?

Any help would be greatly appreciated!

Best regards
Stian Svendsen

[mdarnton]

The first thing you need to know is that the one that is there is a two-part screen. On the side you see is the smooth side of a plain ground glass. Inside, facing the lens, is the smooth side of a plastic fresnel lens. The rough sides of the gg and Fresnel are against each other.

In order for the focus to come out right, you need to always have either the Fresnel or a spacer the thickness of the Fresnel in position--you can't just replace both of them with one modern ground glass.

What I would do if I were you is take out the GG and Fresnel, soak them for a little while in water with a bit of dishwashing detergent, gently wipe them as clean as you can get them, and then rinse in distilled water and dry without wiping. Be very tender on the side of the fresnel with concentric lines--it shouldn't need much cleaning, anyway.

You can use solvents if necessary on the glass, to take off framing lines, etc. Acetone would be good. But NOT on the plastic fresnel, which would dissolve and be damaged. On that you can only use soap and water--no brushing, nothing harsh, no cleaning pads. To clean up the smooth side of the fresnel, which is probably scratched, I bought a plastic polishing kit, three bottles and a cloth for about $10, and it worked great. Don't do anything to the side of the fresnel with the concentric lines on it--it's too easy to damage. Since it's been facing in, it should only be a bit dirty, anyway.

You may find that the whole thing cleans up nicely, or that you only need to replace the outer ground glass, not the fresnel. I'd definitely try a good cleaning first.

[Jim Jones]

Congratulations on getting a pristine Crown Graphic. They are a wonderful tool and a fine example of excellent engineering and construction. Mdarnton's advice is good, but may not apply to some earlier Crown Graphic cameras. For more information on these, go to http://graflex.org/speed-graphic/features.html#Focusing and scroll down to Graflok Back and Graphic Back. In addition to factory variations, many Speed Graphics were modified by the owners.

[StianSvendsen]

Thanks guys!
I will remove the screens and try to have it cleaned now.
I will post here later about how it goes.

[Dan Fromm]

The first thing you need to know is that the one that is there is a two-part screen. On the side you see is the smooth side of a plain ground glass. Inside, facing the lens, is the smooth side of a plastic fresnel lens. The rough sides of the gg and Fresnel are against each other.

In order for the focus to come out right, you need to always have either the Fresnel or a spacer the thickness of the Fresnel in position--you can't just replace both of them with one modern ground glass.

To expand on what Jim wrote, there's no guarantee that the OP's Crown has a fresnel. When the camera was first brought to market Graflex didn't offer it with a fresnel.

Whether the camera has a fresnel or not, the ground side of the ground glass must face the lens. If it is reversed (shiny side towards lens), focusing the camera on the GG will never give the desired plane of best focus.

Stian, ain't no 70 year old Crown Graphics. It was introduced in 1947. Post your camera's serial number and with luck someone will tell you when the s/n was assigned.

[StianSvendsen]

1947 is 67 years ago, I just rounded it up to 70.
Of course it is probably not the first off the line, just saying this thing
is old and it was used by press. Maybe they took better care of their gear
back in the days.

And as you said Dan, the camera only has one glass, no fresnel.
So I'm guessing I should get a new glass and a fresnel?
Will the fresnel affect my focus?

[Jim Noel]

if it has a single glass, clean it as above and re-install it with the smoth side toward you, the ground side facing the lens. forget the fresnel. You should be able to focus well without it.

[StianSvendsen]

Thanks!
I'm waiting for it to dry up now, it seems to have cleaned up nicely.
I will see how much better it gets, but until now shooting a dark scene
has been a total pain in the ass. Only highlights are visible, making composition
more of a challenge than it needs to be.

[StianSvendsen]

Okay guys, the clean worked wonders.
Not only is it brighter, it also appears a lot sharper.

Thanks a lot!

[lenser]

Another thing that shooters of these used to do in the old days was to use a tiny bit of Vaseline on the rough side of the ground glass and thoroughly rub in in all over which does help with the brightness, almost turning the ground glass clear. I don't know if this was done against the plastic ground glass, so I would research that a bit before doing it.

[StianSvendsen]

I think I will be more than satisfied with the screen now, but thanks for the tip!