Ground Glass Masking?

Brandonium · Apr 6, 2016

Hey all,

I've decided that I would like to use 120 roll film on my Pacemaker Speed Graphic. I'm looking for a 4x5 glass (mine needs replacing anyways) that has markings for 6x6, 6x7, 6x9 and 6x12. I'm not really finding much on this. I know that Linhof makes one (excluding 6x6) but that's about all I have been able to find. I have an email into Steve Hopf to see if he would be able to do this. I'm looking for my ground glass to look similar to this. Thoughts?

RobC · Apr 6, 2016

looks like you already found the one you want

DREW WILEY · Apr 6, 2016

Fine point Sharpie pen and a ruler.

Brandonium · Apr 6, 2016

I cannot guarantee that this will fit my graphlex back or can I?

RobC said:
looks like you already found the one you want

Old-N-Feeble · Apr 6, 2016

Brandonium said:
I cannot guarantee that this will fit my graphlex back or can I?

Length and width can be trimmed (stained glass grinder) if necessary. Thickness shouldn't be a concern unless the GG is so thick it can't be mounted. Make certain the line guides match up with your RFH openings.

DREW WILEY · Apr 6, 2016

I HATE grinding down groundglass edges. If you don't have special gear, wax down a sheet of black silicon-carbide wet/dry paper to a completely flat
surface, wear thick gloves, and gently rub the sides down square by hand. I happen to own a true linear sanders, but those don't come cheap.

Brandonium · Apr 6, 2016

I'll measure mine once the camera gets back. I'm not so sure I am properly skilled to do any of this especially when dealing with glass. We'll see. Perhaps I will get lucky. I need to inquire to the actual dimensions of the Linhof glass since I do not know to be honest. Also, while the Sharpie idea sounds nice I never did well in art class and I would like my setup to look somewhat professional and nice.

Old-N-Feeble said:
Length and width can be trimmed (stained glass grinder) if necessary. Thickness shouldn't be a concern unless the GG is so thick it can't be mounted. Make certain the line guides match up with your RFH openings.

RobC · Apr 6, 2016

if you start changing GG make sure you understand about shimming/adjustment of its depth becasue if you get it wrong and don't know the original depths and thicknesses, you'll never get it back to where its was. You will need to measure the depth of current GG very accurately before you alter anything. Ideally replacement glass would be same thickness.
If replacement fits from outside of back then it should be simple even if glass thickness is different. But if its inserted into back from camera side then it gets very tricky if glass thickness is different as shimming will need to be adjusted to get same depth as original GG.

May I suggest you just get a piece of clear acetate or thin perspex for each format you want to use, cut it to size with correct size opeing and fit over outside of GG and put in place in the same way as fitting an external fresnel, there may be clips on back for this. Or get some of those little double sticky sided labels so you can just stick it to GG on outside. Then you don't need to mess with GG at all. And you can take it off when not using it.

BrianShaw · Apr 6, 2016

I think there are only 2 options with the Pacemaker Graphic in terms of placement of the ground surface of the GG: with Graflite fresnel or without. Okay, maybe another option: Graflite and GG in the correct orientations or not.

BrianShaw · Apr 6, 2016

I've used a variety of masking techniques:

- Xerox transparency overlay on top of the GG

- Drafting "lining" tape on top of the GG

- permanent marker on top of the GG

- pencil lines on the ground side of the GG

All worked good enough but the overlay became annoying very quickly. It was just one more thing to look through.

DREW WILEY · Apr 6, 2016

Custom decals are easy enough to order if you have the given pattern on a file. My own method is a little different. I'll mark only the corners of the
smaller format on the GG. That way, all those misc grid lines don't annoy me if I'm trying to compose a full-sized image. Then when I switch over to
a rollfilm back, I merely slip in a piece of 5-mil frosted mylar with the appropriate cutout in it. The corners of this obviously align with those little dots, which I can also use for a quickie roll film shot if I don't want to install the mask, which merely slides under the groundglass clips for retention.
But what this gives me is something transluscent, where only the roll film format is fully visible on the GG through the cutout, but anything outside
those borders slightly visible too, helping evaluate adjacent parts of the scene if necessary. The polyester itself is waterproof, tough (except for kink
marks if you bend it too hard), easy to clean, inexpensive, and dimensionally stable.

Kilgallb · Apr 6, 2016

I masked mine for 6x9 by exposing a 4x5 sheet and developing and fixing. I cut an opening slightly smaller Than 6x9. I just place the film on the viewfinder when I shoot 6x9. i tape it in place.

donkittle · Apr 9, 2016

The guy running emulsive.org has a template you can print on transparency.. Bring it into photoshop and fill in the lines, if you think that would help..
http://emulsive.org/articles/free-download-large-format-grid-overlay-screen

mdarnton · Apr 9, 2016

Something to consider is that some backs don't center the roll film frame exactly the way you think would be logical. I suspect the glass you can buy is set up for that maker's camera and roll holder and may not work in every instance. I've been looking for some nice plastic to cut my own framing guide, and it never occurred to me until this moment to use film as Kilgallb just suggested. Stupid me!

Brandonium · Apr 11, 2016

Awesome suggestions! One thing that I did not realize since I hadn't taken the ground glass out was the actual measurement. It appears my ground glass measures an image size of 100mmx122mm. Just to clarify this is the typical image size found on a 4x5 negative?

*Also, the thickness is about 1/8 of an inch. There seems to be a fresnel lens before the ground glass which is 1/16 in thickness followed by the ground glass of the same thickness. I see no shims for what it's worth.

EMULSIVE · Dec 6, 2016

donkittle said:
The guy running emulsive.org has a template you can print on transparency.. Bring it into photoshop and fill in the lines, if you think that would help..
http://emulsive.org/articles/free-download-large-format-grid-overlay-screen

Has it been nearly a year since I posted that? Wow.

If anyone would like an update, please do let me know.

Doremus Scudder · Dec 6, 2016

Brandonium said:
Awesome suggestions! One thing that I did not realize since I hadn't taken the ground glass out was the actual measurement. It appears my ground glass measures an image size of 100mmx122mm. Just to clarify this is the typical image size found on a 4x5 negative?

*Also, the thickness is about 1/8 of an inch. There seems to be a fresnel lens before the ground glass which is 1/16 in thickness followed by the ground glass of the same thickness. I see no shims for what it's worth.

I know this thread is a bit older, but for those contemplating the same thing:

If you've got a Fresnel screen on the lens side of your ground glass, just keep it and don't even think of replacing it. Not only is your set-up about as bright as you can get, but the camera has been designed to focus correctly with this particular configuration of Fresnel and ground glass. Replacing it with anything but exactly the same Fresnel/ground-glass screen will result in a focus shift and incorrectly focused negatives. Better to get an overlay or a protective glass screen with the lines you need on them (or use a mask).

Best,

Doremus

removed account4 · Dec 6, 2016

Brandonium said:
Hey all,

I've decided that I would like to use 120 roll film on my Pacemaker Speed Graphic. I'm looking for a 4x5 glass (mine needs replacing anyways) that has markings for 6x6, 6x7, 6x9 and 6x12. I'm not really finding much on this. I know that Linhof makes one (excluding 6x6) but that's about all I have been able to find. I have an email into Steve Hopf to see if he would be able to do this. I'm looking for my ground glass to look similar to this. Thoughts?

i make grids for ground glass and sell them
i have a few left if youare interested,
they aren't marked like yours though ...
or you can make your own, it costs a few bucks
at a chain copy-shop for the b/w sheet
basically you go into your mac paint, mac draw,
photoshop of whatever program you use,
and you print it out on overhead projector film
or some call it "transparency" .
you get your plain ground glass and just
put this under the clips infront of it if you
want to go high tech, you can get
whats called sticky-film, which is that stuff
oil change places put on your windshield,
and you have the grid printed on that. its a big more $$ ( like 20$ a sheet )
but you can remove it if you want.
i've been using a mylar sheet ( the 1st method i described )
for about 30 years, its cheap and works great.
the 2nd method is more morey than i wanted to spend.

Ground Glass Masking?

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