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Mirror in B Graflex

 
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dannysoar



Joined: 27 Oct 2005
Posts: 11
Location: New England

PostPosted: Fri Oct 28, 2005 12:23 am    Post subject: Reply with quote


Hello- I'm new here and hope some one can answer some questions.

I was chasing the spiders and owls out of my father's old B Graflex with hopes of taking pictures with it.

When I removed the ground glass I was horrified to find the mirror was very dirty. I gently wiped a corner with a camel hair bush and found that it was silvered on the back- like a bathroom mirror and was able to clean the mirror with soft paper towels dampened with Windex.

It is my understanding that all these mirrors were originally front surfaced. Is this correct?

Perhaps this is a repair. (Although what I think I know of the history of the camera makes this hard to believe) In which case I would think the thickness of the glass would cause the focus to be off, unless the repairer was able to move the mirror. The ground glass and the back seem to be unmodified

I took some pictures of my yard at f/16 and the negatives look sharp, although I do not, as yet, have a way to print them.

I hope to test the focus on the kitchen table at f/4.5 by photgraphing a ruler and cutting out a piece of the negative small enough to scan in a 35mm scanner.

The ground glass image seems fine with no double image. If I can get the camera to focus is there any reason to change it?

I hope all this makes sense
Thank you
David
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serdukoff



Joined: 03 Dec 2004
Posts: 13
Location: Boston Massachusetts USA

PostPosted: Fri Oct 28, 2005 3:12 am    Post subject: Reply with quote

Hello Dave,
The B series Graflexes, per my limited experience, have the bathroom-style mirror, using your own terminology. The later ones, definitely the Super Ds, have front surface mirrors. So, it looks as though the mirror in your camera is indeed original. Definitely, should you want to go for replacement of the mirror with the modern thin, coated front surface stock, you will need to readjust the ground glass placement. In your case the GG will go up, which is simple, by the difference well, it can be calculated, but will depend on the thickness of the front surface stock you will use. The readily available on the market today stock is .054 (fifty-four thousandths of an inch), or 1.4mm in a way, close to the thickness of the original mirror in your series B camera. I myself in your case would replace the mirror. Off-topic: there is another big problem Graflexes, especially the big ones, are suffering from. It is mirror flexing. Since they use one offset mirror stop at the bottom to position the mirror for viewing, this causes uneven torque distribution through the plane of the mirror carrier subplate, as it is being forced against the mirror stop by the springs that are pushing the mirror upward. If you remove the lens (or lensboard with the lens on Ds) and look inside your camera with its mirror down, you will notice that the left corner of the mirror is higher than the right one, resting against the stop. In severe cases not only the mirror subplate, but the mirror itself is flexing, causing loss of focus at the ground glass. I would speculate, that camera samples that were stored with their mirrors in the viewing position for extended periods, suffer from twisted mirror problem more than fresher samples. I suggest you not tighten-up the torque spring controlling the mirror, to make its action more agile. The consequence of this can be more mirror twisting, less precise focus. Generally, I suggest that when calibrating your camera, choose a certain portion of the frame for critical focus. Such as, if you intend to photograph mainly portraits, select the center of the frame, or slightly above center, where the eyes of your subjects will be placed, for calibrating the focus of your camera. The rest of the frame will be reproduced less accurately versus the real image on film, in terms of sharp focus. But in the end, the whole thing about Graflexes, as I understand it, is an endless array of compromises. But it appears that it is one of the uncertainties people are enjoying when using Graflexes. If you need a large format SLR for more serious, less uncertain work at wider apertures, there are other large SLRs out there, a lot more precisely built, but not nearly as common as Graflexes. I hope my reply helps you a bit.
Regards,
Dmitri Serdukoff


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dannysoar



Joined: 27 Oct 2005
Posts: 11
Location: New England

PostPosted: Thu Nov 03, 2005 2:42 am    Post subject: Reply with quote

I did a test by taking a picture of a ruler. Racked all the way out, at f/4.5, the camera focuses better than I can see . So I'd say either my Graflex B was built with the silver on the back of the mirror or that it doesn't matter if has been changed.
David
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bertsaunders



Joined: 20 May 2001
Posts: 577
Location: Bakersfield California

PostPosted: Sat Nov 05, 2005 5:05 am    Post subject: Reply with quote

I have repaired well over a 100 Graflex Slr's of every type and description, have yet to find a "front surfaced mirror" A few Cameras in my collection go back to 1912...
all mirrors (in the ones I have ever worked on) are surfaced on the back!
Have a nice day.....Bert
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dannysoar



Joined: 27 Oct 2005
Posts: 11
Location: New England

PostPosted: Sun Nov 06, 2005 3:58 am    Post subject: Reply with quote

Bert- Things are screwed up because in a dismal brain fog I created two mirror threads . I guess this is the real mirror thread. The other one is a ground glass thread masquerading as a mirror thread.

I distinctly remembered reading that the mirror was front silvered. So mostly to keep track of state of my memory i checked.

From pg 389 of the 1954 edition of Graphic Graflex Photography, which sure looks like an official Graflex book, I find this.

"...the surfaceof the mirror is a highly polished film of chrome-aluminum compound applied to the FRONT of the glass to avoid double reflections, which are annoying and particularly disturbing in poor light." (The caps are mine)

The same thing can be found in the earlier editions.

I don't know what to make of this.

On the other thread I quote the book on the Ekatlite Field Lens.

party on
David




[ This Message was edited by: dannysoar on 2005-11-05 19:59 ]

[ This Message was edited by: dannysoar on 2005-11-05 20:00 ]

[ This Message was edited by: dannysoar on 2005-11-05 20:01 ]
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dannysoar



Joined: 27 Oct 2005
Posts: 11
Location: New England

PostPosted: Sun Nov 06, 2005 6:14 pm    Post subject: Reply with quote

It just keeps getting more curiouser . I found the following on eBay

By It Now $29.99
#7559355730
MIRROR for GRAFLEX SLR Series B D Super D Auto?? 4X5

"This is a mirror for a Graflex 4X5 SLR. I have been told it will fit the Series B and D as well as the Super D. It is also supposed to fit the Auto Gralex. The mirror is made of glass and the silvering is on top. There is some removal of the silvering at the outer edges but this I believe is hidden by the clamps that hold on the mirror. When viewed obliquely there are are some minor cleaning wisps visible but I do not believe they will have any effect on the image. Mirror is nice and bright and shiny. Dimensions: wide top tapered end is 4 1/4 inches, bottom narrow tapered end is 3 1/8 inches and the depth is 3 inches. Hard to find.

David
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bertsaunders



Joined: 20 May 2001
Posts: 577
Location: Bakersfield California

PostPosted: Mon Nov 07, 2005 3:54 am    Post subject: Reply with quote

My statement stands, "I have never worked on a SLR, with it's mirror silvered on the topside", I didnt mean to imply that some mirrors, at some point in time, could not have been silvered on the topside,I just have never seen one in 25 years!
(And impossible to find except in body only or junk cameras) I have not been able to find glass that thin, for replacements!
Have a great week.....Bert

[ This Message was edited by: bertsaunders on 2005-11-06 19:58 ]
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dannysoar



Joined: 27 Oct 2005
Posts: 11
Location: New England

PostPosted: Mon Nov 07, 2005 3:16 pm    Post subject: Reply with quote

Bert- I certainly didn't mean to question your statement. It is the discrepency that stirs my interest. I would think that after 100 Graflexes you would have seen then all. On the other hand I think the book was put together by the Graflex company. As for the eBay listing, I don't think any information found on eBay should be regarded as trustworthy.

The only thing I can think of is that the front surface mirror might have been a later development. The talk about "chrome aluminum" peaks my interest. It sounds sort of post war.

Or maybe the guy that wrote the book, was plain wrong and was repeating an urban legend. This theory gains credibility when we discover the chapter was written by a man who is described as a "photographer, consultant, publisher" It is common belief that consultants, taken as a class, are only slightly more reliable than eBay guys.

Party on
David





[ This Message was edited by: dannysoar on 2005-11-07 07:17 ]
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scifan



Joined: 21 Dec 2005
Posts: 21
Location: saskatchewan

PostPosted: Wed Dec 28, 2005 7:46 pm    Post subject: Reply with quote

My rb graflex series b has a front surface mirror.It was made in 1947.My understanding is that early graflexes had rear surface mirrors and later cameras had the front surface mirrors.
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Billy Canuck



Joined: 04 Apr 2006
Posts: 153
Location: Calgary AB Canada

PostPosted: Sat Aug 11, 2007 8:03 pm    Post subject: Reply with quote

Just as a final (?) word to this thread, according to Morgan and Lester's Graphic Graflex Photography, "after 1936 all Graflex cameras were equipped with first surface mirror, eliminating double image on the ground glass."
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