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peter k Joined: 26 Dec 2009 Posts: 207 |  Posted: Tue May 29, 2012 2:44 pm Post subject: 3x4 ..widest lens
At
http://graflex.org/speed-graphic/which-model.html
it states that: | Quote: | | The widest suitable for a Speed is 80-90mm. |
referring most likely to a 4x5, but was wondering what is the widest that would normally work with a 3x4 speed?
There is a Schneider 80mm f2.9 I've been looking at.. and wondered if it would function well on a 3x4, with enough room to use the movements if needed.
The reason for this question is that when I use the 120 roll film adapter on the 3x4, the 135 Optar gives me a to 'full' of a negative at times. |
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Dan Fromm Joined: 14 May 2001 Posts: 2165 |  Posted: Tue May 29, 2012 6:37 pm
Peter, the quotation is wrong. For 3x4 Speed Graphics, minimum flange-to-film distances are:
Anniversary: 63.5 mm
Pacemaker: 66.7 mm
Its wrong for 4x5s too, the 4x5 Pacemaker Speed's minimum is also 66.7 mm. And its horribly wrong for 2x3s. The shortest lens I use on my 2x3 Pacemaker Speed is a 1.75"/2.8 Elcan in barrel; it covers only 6x6, though, doesn't come close to covering 2x3.
If you check data from lens makers' sites or the slightly out-of-date list of lenses on this site you'll see that there are many lenses with focal lengths as short as 60 mm +/- that will focus to infinity on your 3x4 Speed. Pay attention to coverage, I believe you need a lens that covers at least 127 mm to get good image quality in the corners.
Good luck, have fun, don't believe everything you read,
Dan |
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peter k Joined: 26 Dec 2009 Posts: 207 |  Posted: Tue May 29, 2012 6:47 pm
thanks allot for the clarity... reading different posts, it seems most 3x4 speeds had a 127mm, although press people liked them for the 4x5 because of the wider image, even if they didn't get the corners.
I have an Anniversary, been loving it, even though a 3x4.. |
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Henry Joined: 09 May 2001 Posts: 1662 |  Posted: Tue May 29, 2012 7:24 pm
The 10th ed. (1954) of "Graphic Graflex Photography," p. 24, says the 65 and 80 Wide Angle Optars and Wide Field Ektars will work on 3x4. Don't know about coverage w/movements, though. |
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peter k Joined: 26 Dec 2009 Posts: 207 |  Posted: Tue May 29, 2012 7:38 pm
Thanks for the help, ..
The lens I'm looking at is not an Optar... and reading the info again, it states that it has a built-in focusing mount and depth-of-field scale, and can be used with any bellows camera set at infinity.
So no movement using it on the speed.
Yet with a roll film adapter that shoots 6x6, I really don't have to worry about the corners. |
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45PSS Joined: 28 Sep 2001 Posts: 4081 |  Posted: Tue May 29, 2012 7:40 pm
You are confusing focal length with image circle. True, a 127mm focal length is considered "normal" for the 3x4 camera but a lens needs to produce an image circle of [ the square root of 3 1/4² + 4 1/4²; 10.5625 + 18.0625=28.625 taking the square root = 5.3502336397581741495630759274711, convert to millimeters =]135.89593444985762339890212855777mm to cover the negative.
Now the actual image size is less than the negative size and the film holder specifications state that the image area is 4.228 x 3.131 so 4.228² =17.875984, 3.131² =9.803161; adding them =27.679145 and taking the square root = 5.2610973190010465724479405799684, convert to millimeters = 133.6318719026265829401776907312 to cover the image area of a 3 1/4 x 4 1/4 film holder.
Image circle needed for a roll film holder
A= the short side of the format you wish to cover
B= the long side of the format you wish to cover
C= the diagonal of the format
A²+B²=C²
1 inch = 25.4 millimeters. |
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Henry Joined: 09 May 2001 Posts: 1662 |  Posted: Tue May 29, 2012 7:42 pm
I just love these approximations  |
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45PSS Joined: 28 Sep 2001 Posts: 4081 |  Posted: Tue May 29, 2012 7:50 pm
With windows calculator in Scientific mode the copy-paste makes rounding extra key strokes.  |
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Henry Joined: 09 May 2001 Posts: 1662 |  Posted: Tue May 29, 2012 7:58 pm
I feel cheated. I can only enter nine digits into my Mac 10.6 Dashboard calculator.  |
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1banjo Joined: 16 Nov 2008 Posts: 492 |  Posted: Tue May 29, 2012 8:02 pm
hey peter k
just so you know that Schneider 80mm f2.9 was sold on a lot of 23 cameras BUT It DON'T COVER a 6x9 by Schneider lens data @
http://www.schneideroptics.com/info/vintage_lens_data/large_format_lenses/xenotar/data/2,8-80mm.html
it shows a IC of 91mm a 23 needs of about 99mm & your 3x4
will need 127 or so
NOT 80mm or 90mm are wide angle!! they needs to say
wide angle or wide field!!!!! |
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peter k Joined: 26 Dec 2009 Posts: 207 |  Posted: Tue May 29, 2012 10:11 pm
haha.. oh boy...
I'm in lens trouble again  | Quote: | | He told me that people like me who wanted SLRs with on-board light meters would never learn the basics. I thought he was wrong but you just proved him right. |
ok.. thanks 45pps,
(for 4x5 positive post, squared)
yes I am confusing focal length with image circle... again and again..
maybe if I became a lens... 
I'll have to sit down and copy ur math.. and perhaps the light will shine through to the corners.
Banjo... more clarification,, thanks.. I can use all the help I can get.
Ok//.. math or not... velll keep trying, danks fer yer patience.  |
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45PSS Joined: 28 Sep 2001 Posts: 4081 |  Posted: Wed May 30, 2012 2:43 am
My Graphic 22 RFH has a 57mm x 57mm film opening. It requires a 81mm image circle to cover it.
My Graphic 23 RFH has a 57mm x 78mm film opening. It requires a 96.6mm image circle to cover it. |
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Dan Fromm Joined: 14 May 2001 Posts: 2165 |  Posted: Wed May 30, 2012 2:13 pm
| 45PSS wrote: | | My Graphic 23 RFH has a 57mm x 88mm film opening. It requires a 105mm image circle to cover it. |
Go measure again. None of my 2x3s is that wide. The ones with pin rollers are 57 x 78. |
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45PSS Joined: 28 Sep 2001 Posts: 4081 |  Posted: Wed May 30, 2012 7:04 pm
error corrected. |
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