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Tessar or Ysarex?
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miket-nyc



Joined: 18 Apr 2018
Posts: 38
Location: NYC

PostPosted: Sun Apr 22, 2018 3:03 am    Post subject: Tessar or Ysarex? Reply with quote

My miniature Speed Graphic came with an uncoated 4.5/4 3/8" "TESSAR Ic" (no brand name) in a Compur shutter. I also have a coated 4.7/127mm Rodenstock Ysarex in a Prontor SVS shutter, salvaged from a Polaroid 110A. Both lenses fit the camera's lensboard and the Kalart rangefinder can be adjusted to work with either.

So which is better? I'm drawn to the Rodenstock because it's a more modern design (and Graflex liked it enough to use on the XL), and it's coated. I'm also a bit suspicious about a no-name Tessar -- it's hard to believe Zeiss would be ashamed to put their name on it if it was theirs (though perhaps they couldn't if it was during WW II). Main downside of the Ysarex is that the Prontor doesn't have a "T" setting for ground glass focusing, but I could figure-out a workaround for that.
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Dan Fromm



Joined: 14 May 2001
Posts: 2020
Location: New Jersey

PostPosted: Sun Apr 22, 2018 4:41 pm    Post subject: Reply with quote

Why ask us what we think about lenses we can't test when you have them and can test them?

Take some test shots and you'll know which one works better for you.
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miket-nyc



Joined: 18 Apr 2018
Posts: 38
Location: NYC

PostPosted: Sun Apr 22, 2018 7:14 pm    Post subject: Reply with quote

Dan Fromm wrote:
Why ask us what we think about lenses we can't test when you have them and can test them?

Take some test shots and you'll know which one works better for you.


It's a waste of time to test things that have already been tested by reputable people, especially if the test is quite a bit of trouble. Have you tried crashing your car to see if seat belts and air bags really work? To do a proper test myself, I'd have to mount a new lens on the lensboard, reset the infinity stops, and recalibrate the rangefinder, then undo all those things if the Tessar turned out to be the better lens.

I'm an experienced photographer but a beginner in this format, and someone here has probably tried both lenses on this camera. Maybe several people have, because film for roll-film Polaroids hasn't been available for about 30 years and there must be many orphan 110A and 110B cameras with this lens kicking around.
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45PSS



Joined: 28 Sep 2001
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Location: Mid Peninsula, Ca.

PostPosted: Sun Apr 22, 2018 7:59 pm    Post subject: Reply with quote

Pedigree does not mean squat in old lens. How they have been handled throughout the ages matters more.
Look at the lens more closely, it probably says Bausch & Lomb on the outside of the front lens barrel. Bausch and Lomb made Zeiss tessars under license from Zeiss.
1941 Graflex catalog.
http://www.cameraeccentric.com/html/info/graflex_10.html
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Dan Fromm



Joined: 14 May 2001
Posts: 2020
Location: New Jersey

PostPosted: Mon Apr 23, 2018 12:06 pm    Post subject: Reply with quote

miket-nyc wrote:
Dan Fromm wrote:
Why ask us what we think about lenses we can't test when you have them and can test them?

Take some test shots and you'll know which one works better for you.


It's a waste of time to test things that have already been tested by reputable people, especially if the test is quite a bit of trouble. Have you tried crashing your car to see if seat belts and air bags really work? To do a proper test myself, I'd have to mount a new lens on the lensboard, reset the infinity stops, and recalibrate the rangefinder, then undo all those things if the Tessar turned out to be the better lens.

I'm an experienced photographer but a beginner in this format, and someone here has probably tried both lenses on this camera. Maybe several people have, because film for roll-film Polaroids hasn't been available for about 30 years and there must be many orphan 110A and 110B cameras with this lens kicking around.


As 45PSS already said, with used lenses condition is important.

You need more time using y'r new camera. You need to learn what Kalarts can and can't do. And you need to get out of the small format mindset.

A Kalart can be adjusted for only one lens at a time. There are a number of ways to use a Kalart that's calibrated for a lens to focus another lens. IMO the best thing to do, and the only way to test lenses, is to shoot from tripod and focus on the ground glass.

Many, many used Graphics have rangefinders. There's no guarantee that the RF on a recently-purchased Graphic is calibrated for the lens on it.

Now go crash your car. With luck you'll survive.
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miket-nyc



Joined: 18 Apr 2018
Posts: 38
Location: NYC

PostPosted: Tue Apr 24, 2018 3:54 am    Post subject: Reply with quote

Dan Fromm wrote:
miket-nyc wrote:
Dan Fromm wrote:
Why ask us what we think about lenses we can't test when you have them and can test them?

Take some test shots and you'll know which one works better for you.


It's a waste of time to test things that have already been tested by reputable people, especially if the test is quite a bit of trouble. Have you tried crashing your car to see if seat belts and air bags really work? To do a proper test myself, I'd have to mount a new lens on the lensboard, reset the infinity stops, and recalibrate the rangefinder, then undo all those things if the Tessar turned out to be the better lens.

I'm an experienced photographer but a beginner in this format, and someone here has probably tried both lenses on this camera. Maybe several people have, because film for roll-film Polaroids hasn't been available for about 30 years and there must be many orphan 110A and 110B cameras with this lens kicking around.


As 45PSS already said, with used lenses condition is important.

You need more time using y'r new camera. You need to learn what Kalarts can and can't do. And you need to get out of the small format mindset.

A Kalart can be adjusted for only one lens at a time. There are a number of ways to use a Kalart that's calibrated for a lens to focus another lens. IMO the best thing to do, and the only way to test lenses, is to shoot from tripod and focus on the ground glass.

Many, many used Graphics have rangefinders. There's no guarantee that the RF on a recently-purchased Graphic is calibrated for the lens on it.

Now go crash your car. With luck you'll survive.


I probably should have mentioned that I used to repair cameras for a living in the '80s and I have a machine shop in my basement. I specialized in Leicas back then, but I've done Kalart rangefinders too. Believe me, if you've ever taken apart the rangefinder of a Leica M3, nothing in a Kalart is hard. (Except perhaps finding new beamsplitter mirrors, but the one in this Kalart is fine).

I understand that the rangefinder will need to be calibrated to a new lens. I don't even think it's properly calibrated to the present lens -- that's why this seemed to be a good time to change lenses. The only possible problem with putting on the Ysarex is that its focal length is about 16 mm longer than the Tessar, so the focusing scale on the camera (assuming the Tessar is original) will be slightly wrong. I don't know whether that matters enough to be important, but the only time I'd be using the focusing scale for precision focusing will be if I put a second lens on the camera and need to transfer readings from the focusing scale for lens #1 to another focusing scale for lens #2. I don't know what people do in this case, but I'll worry about that later -- there may be focusing scales online somewhere.

Also. I already have lens #2 -- a wonderful old 180mm f.4 Meyer-Goerlitz Doppel-Plasmat whose rear element can be used alone as a 250mm f.8 Plasmat. (The complete lens is within the bellows capacity of a Miniature Graphic, but not the rear element alone). I don't think it would be possible to close the camera with this lens in place, since the Compur shutter is more than 3 inches wide and sticks out more than an inch from the lensboard, so this will be an occasional lens, not a normal one.

Finally, I've used uncoated lenses before and don't like them. That's another reason to go with the Ysarex. Its condition isn't an issue, because I know the former owner -- me. I used the Polaroid 110A this came on until Polaroid discontinued roll film, then I modified the camera to accept Polaroid film packs and continued to use it occasionally until they discontinued THOSE. The slow speeds on the shutter need a CLA, but otherwise the lens is in fine shape.
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45PSS



Joined: 28 Sep 2001
Posts: 3671
Location: Mid Peninsula, Ca.

PostPosted: Tue Apr 24, 2018 7:22 pm    Post subject: Reply with quote

Quote:
I understand that the rangefinder will need to be calibrated to a new lens. I don't even think it's properly calibrated to the present lens -- that's why this seemed to be a good time to change lenses. The only possible problem with putting on the Ysarex is that its focal length is about 16 mm longer than the Tessar, so the focusing scale on the camera (assuming the Tessar is original) will be slightly wrong. I don't know whether that matters enough to be important, but the only time I'd be using the focusing scale for precision focusing will be if I put a second lens on the camera and need to transfer readings from the focusing scale for lens #1 to another focusing scale for lens #2. I don't know what people do in this case, but I'll worry about that later -- there may be focusing scales online somewhere.

Focus scales are made for each lens like rangefinder cams and Kalart calibrations. A 1mm or 2mm difference in focal length for a 101mm lens will be off at 6 feet to 10 feet, a 16mm difference will be off at 25 feet or greater.
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miket-nyc



Joined: 18 Apr 2018
Posts: 38
Location: NYC

PostPosted: Tue Apr 24, 2018 8:08 pm    Post subject: Reply with quote

45PSS wrote:
Quote:
I understand that the rangefinder will need to be calibrated to a new lens. I don't even think it's properly calibrated to the present lens -- that's why this seemed to be a good time to change lenses. The only possible problem with putting on the Ysarex is that its focal length is about 16 mm longer than the Tessar, so the focusing scale on the camera (assuming the Tessar is original) will be slightly wrong. I don't know whether that matters enough to be important, but the only time I'd be using the focusing scale for precision focusing will be if I put a second lens on the camera and need to transfer readings from the focusing scale for lens #1 to another focusing scale for lens #2. I don't know what people do in this case, but I'll worry about that later -- there may be focusing scales online somewhere.

Focus scales are made for each lens like rangefinder cams and Kalart calibrations. A 1mm or 2mm difference in focal length for a 101mm lens will be off at 6 feet to 10 feet, a 16mm difference will be off at 25 feet or greater.


OK, I see. So does Graflex.org or some other website have reproduction focusing scales for various focal lengths available online for downloading and printing? Or do people normally make new focusing scales from scratch by focusing on the groundglass and marking the scale manually? I'm sure I'm not the first person who's ever wanted to put a different lens on a Graphic, so people must have faced this problem before.
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shutterfinger



Joined: 09 Mar 2007
Posts: 56

PostPosted: Tue Apr 24, 2018 9:19 pm    Post subject: Reply with quote

Quote:
OK, I see. So does Graflex.org or some other website have reproduction focusing scales for various focal lengths available online for downloading and printing?

None that I'm aware of.
A partial list of focus scales for Pacemaker series cameras is available at:
http://www.southbristolviews.com/pics/Graphic/manual-pdf/Grafscalst.gif
Note that the rail and bed parts are a matched pair, only the bed half is marked with the part number.
Best to make your own.
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Dan Fromm



Joined: 14 May 2001
Posts: 2020
Location: New Jersey

PostPosted: Wed Apr 25, 2018 1:23 pm    Post subject: Reply with quote

Thanks for the reply and for explaining what you do and don't want.

I've had and used a number of uncoated Tessars. Fine lenses, most of them.

Y'r Tessar's focal length is slightly longer than normal for 2x3, the 127 Ysarex is longer still, normal for 3x4.

Since you prefer coated lenses -- coating isn't really necessary on Tessars -- and the longer focal length, you don't need advice.
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William Hallett



Joined: 07 Jan 2012
Posts: 56

PostPosted: Wed Apr 25, 2018 5:36 pm    Post subject: Reply with quote

I've made focussing scales using the lensmaker's equation to calculate the distances (1/focal length = 1/(object distance) + 1/(image distance)). I've then laid out the distances accurately using a computer drafting program and printed the scale, making sure to include a reference length to check that the printer doesn't change the scale. The scale is then stuck to the bed using rubber cement (which will not leave a mark if you later remove it). This is crude, but as long as the infinity position is properly lined up the results agree very well with ground glass focussing.

If you want a metal scale, you could put a scriber in the collet of a milling machine or lathe and use the table feed to get the distances accurate.
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miket-nyc



Joined: 18 Apr 2018
Posts: 38
Location: NYC

PostPosted: Thu Apr 26, 2018 4:00 am    Post subject: Reply with quote

William Hallett wrote:
I've made focussing scales using the lensmaker's equation to calculate the distances (1/focal length = 1/(object distance) + 1/(image distance)). I've then laid out the distances accurately using a computer drafting program and printed the scale, making sure to include a reference length to check that the printer doesn't change the scale. The scale is then stuck to the bed using rubber cement (which will not leave a mark if you later remove it). This is crude, but as long as the infinity position is properly lined up the results agree very well with ground glass focussing.

If you want a metal scale, you could put a scriber in the collet of a milling machine or lathe and use the table feed to get the distances accurate.


William Hallett wrote:
I've made focussing scales using the lensmaker's equation to calculate the distances (1/focal length = 1/(object distance) + 1/(image distance)). I've then laid out the distances accurately using a computer drafting program and printed the scale, making sure to include a reference length to check that the printer doesn't change the scale. The scale is then stuck to the bed using rubber cement (which will not leave a mark if you later remove it). This is crude, but as long as the infinity position is properly lined up the results agree very well with ground glass focussing.

If you want a metal scale, you could put a scriber in the collet of a milling machine or lathe and use the table feed to get the distances accurate.


Thank you for this equation! You may consider it "crude" but it's much more sophisticated than the way I planned to do it before. Stuck to the bed with rubber cement (or my preference, contact cement, which is stronger) is plenty good enough. If the surface is protected with epoxy or clear plastic, it should be quite durable enough and easier to read than an engraved metal scale.

Concerning the focal length of lenses, I discovered last night that the 50mm f. 4 Carl Zeiss Flektogon of my Pentacon Six 2 1/4 square SLR (a moderate wide-angle on that format) will focus to infinity on my Mini Speed Graphic, and it may even cover the full negative (or most of it). Unfortunately, it only does this with the front standard parked on the rear part of the track rather than on the part that moves. The Pacemaker and Anniversary design with the linked track and drop bed would definitely help here.

(On the other hand, the thing does have a focusing mount, so I could focus that way. I'm not suggesting that anyone buy 2 1/4 SLR lenses to put on these cameras, but if you happen to have one, see if it works).
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William Hallett



Joined: 07 Jan 2012
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PostPosted: Thu Apr 26, 2018 12:50 pm    Post subject: Reply with quote

When I said "crude", I was referring to the paper scale/rubber cement method. The lensmaker's equation is an exact equation for a "thin" lens, while for a compound lens it is still accurate, except that the focal length and other distances are measured to the nodal point, which for some lenses (e.g. telephotos) is not actually within the lens assembly itself. But this doesn't matter for creating a scale, since a scale requires only differences in position relative to infinity and not absolute distances. To take an extreme example, I have generated a successful scale for a 15" Tele-Optar this way.
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miket-nyc



Joined: 18 Apr 2018
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Location: NYC

PostPosted: Thu Apr 26, 2018 4:26 pm    Post subject: Reply with quote

William Hallett wrote:
When I said "crude", I was referring to the paper scale/rubber cement method. The lensmaker's equation is an exact equation for a "thin" lens, while for a compound lens it is still accurate, except that the focal length and other distances are measured to the nodal point, which for some lenses (e.g. telephotos) is not actually within the lens assembly itself. But this doesn't matter for creating a scale, since a scale requires only differences in position relative to infinity and not absolute distances. To take an extreme example, I have generated a successful scale for a 15" Tele-Optar this way.


Right. Sorry I misunderstood. I assume when you're using the equation you don't try to measure the number of millimeters forward from infinity, but just measure the distance to the object and focus the image on the groundglass. Is that correct?
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William Hallett



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PostPosted: Fri Apr 27, 2018 12:31 pm    Post subject: Reply with quote

Sorry - I should have defined the variables in the equation more carefully. The object distance is the distance from the object that you're photographing to the nodal point of the lens, while the image distance is the distance from the nodal point to the image (i.e. groundglass). To generate a scale, you calculate the image distance at a number of different object distances. Start at infinity (for which the image distance is equal to the focal length, since 1/infinity = 0), then do (say) 50 ft, 25 ft, 15 ft, 10 ft, 6 ft (these are usually the numbers on Graflex's scales). For each of these, calculate the difference between the image distance and that at infinity - this is then the distance from infinity to lay off on the scale for that particular point. Note when you are using the equation that your units must be consistent - i.e. all measurements must be in the same units, whether mm or ft or inches.

The only objection I can think of to this method is that the actual focal length of a given lens may be a little different from that marked on it. However, if you calculate the effects of an error of a couple of millimeters in focal length on the scale, you will find that it is almost negligible. The final test, of course, is to check your scale against groundglass focussing.
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