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View Full Version : replacing the ground glass on a Wista Field 45dx?



l2oBiN
20-Sep-2010, 13:39
I am thinking of potentially replacing the ground glass on the wista field 45dx to a ground glass with grid lines, however, I am unsure of how difficult this is to do, would i throw anything into misalignment and would need to get the camera re calibrated? if so, is the calibration procedure easy? Can I do it myself? Also what is the best ground glass that I can buy? the ground glass I have at the moment is the original wista field 45dx and I think it has a farsnel behind it...

Steve Barber
20-Sep-2010, 14:52
Search on eBay for “Ground Glass” and look for Steve Hopf's Ground Glass Store or “Photofixation”. He will make the ground glass to your specifications—fast, easy, not expensive and good quality.

I do not have a Wista, but, hopefully, if there is a difference specific to it, someone more knowledgeable than I will correct this. As to installation, in general, the following should apply:

When putting in the ground glass, the rough side goes to the front of the camera, towards the lens. If the Fresnel lens is in front of the ground glass; make a note of how it is installed before removing it and re-install it as it was after replacing the ground glass. If it is under the ground glass, then just leave it, as is, and put the new ground glass where the old one was and fasten it in place. Be sure that any shims or spacers go back in the same way they came out. Do not over-tighten any screws.

You should not have any calibration problem if you put everything back as it was. Accurately focus on a test subject and make a test shot. If the negative is not in focus, then you will have to re-calibrate. That is not likely and you can do it yourself, even though it may be a bit tedious to do. In that regard, one caveat applies. If you have a combined ground glass and Fresnel, all in one, with a clear cover glass over it, then you will have to replace it with a like product, probably one you will have to get from Wista.

Frank Petronio
20-Sep-2010, 15:23
The focusing happens on the rough surface of the ground glass, so on most cameras the back is built and milled to be in the right place. On fancier cameras like Linhofs you will often find thin metal shims to make things "perfect".

As fresnels, it's easiest to stick to the way the factory did it, keep everything identical.

Eric Biggerstaff
20-Sep-2010, 15:48
Heck, you can always take the ground glass you have and with a pencil and graph paper create your own gridlines. It is easy to do and if you decide you don't like gridlines they wash right off! I have them on mine, easy to do and you don't need to spend a dime!

l2oBiN
21-Sep-2010, 16:16
Do you mean draw the pencil grid on grid paper and then rub it on the ground glass? Will I be able to have them rubbed off?

IanG
21-Sep-2010, 22:23
Wista make a superb combination fresnel/focus screen, it's one of the brightest I've used. The screen uses a cover sheet with the grid lines, These are the codes Bob Salomon gave me in a previous post:

211229 is a Fresnel/gg sandwich, requires protective glass.
211240 is a plain protective glass.
211241 is a ruled protective glass.

If you use a plain glass screen you can draw a grid direct onto the glass with a sharp pencil, an alternative is china-graph pencils I used a blue one for grid lines and a red one for 6x9/6x7 formats, that was back in 1976 :D still OK today.

You draw the template on graph paper or computer and place it below the gg as a guide.

Ian

Doremus Scudder
22-Sep-2010, 03:47
To answer your question about alignment:

If you have a Wista DX with stock ground glass and no modifications to the back, you can use any ground glass as long as it fits in the opening. A factory Fresnel works well too (I have both for my Wistas). There will be no alignment problem unless you get a Fresnel set-up with the Fresnel lens sheet between the focusing surface of the ground glass and the lens.

If you have the factory Fresnel already (it has the word "Wista" in a corner), then getting the gridded cover sheet would seem to me to be the best solution.

A word about gridded ground glass and wooden field cameras like the Wista: If you are planning to use the grid lines as guides for carefully aligning architectural photographs, etc. make very sure that the ground glass is mounted in the opening so that the grid lines are parallel to the edges of the film holder when inserted. There is enough play in wooden camera backs that you can end up with the grid lines "skewed" a bit, making all your careful leveling and aligning somewhat superfluous, as the image on the negatives.

Sometimes, this misaligns parallel lines in the image. Usually, though, you end up with a negative that has an image that is still "square," but tilted in relation to the film edges. This is no problem if you have a bit of breathing room around the image you want, but if you work out to the edges, it can, frustratingly, clip part of the image you wanted.

I had to shim the edges of my gridded ground glass to keep it from shifting around. Sometimes you need to decide which surfaces the filmholder needs to be tight against as well in order to ensure that it goes into the same position every time (e.g., make sure it is pressed down flush against the bottom of its slot and not tipped or shifted one way or the other).

Good luck,

Doremus Scudder

GPS
22-Sep-2010, 06:03
Instead of using pencil made lines that are not easy to get rid off you can use transparent Scotch tape cut to narrow stripes. The advantage is that you can put them on the glass and reposition at will. They do not obstruct the vision and yet are visible. Alternatively you could made blackish lines on the Scotch tape stripes if you want more pronounced lines.

Partick1
24-Feb-2017, 13:29
I'm about to replace the protective screen on a Wista 45D. Does anyone know how to remove the two chrome retaining springs? The only way I can see is to remove the metal frame held in by 6 very small screws. thanks