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Newbie question: lenses
Hi. I'm brand new to LF, and just bought my first camera and lens. I have a
question about the lens, a Schneider Angulon 90mm f/6.8. I know it's old; the serial number is is mid 5 million, making it a two years my senior. The trouble is, I can't seem to find any information about it on the web. What I did find conflicted with everything else. I'm looking for just the angle of coverage and coverage at infinity focus. It was mere curiosity before; now that I have it in my hands, I'm concerned. I have loupes with more glass than this lens has; it's not at all what I was expecting. Is this reasonable for a 4x5 wide angle lens? Will I get reasonable coverage and movement on 4x5? The camera hasn't arrived yet, so I'll have to wait a few more days to find out. In the meantime, you can help drive me crazy with more rumors and suppositions. What can you tell me about this lens I bought? Thanks. Mike. |
#2
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Newbie question: lenses
"MikeWhy" wrote in message . com...
Hi. I'm brand new to LF, and just bought my first camera and lens. I have a question about the lens, a Schneider Angulon 90mm f/6.8. I know it's old; the serial number is is mid 5 million, making it a two years my senior. The trouble is, I can't seem to find any information about it on the web. What I did find conflicted with everything else. I'm looking for just the angle of coverage and coverage at infinity focus. It was mere curiosity before; now that I have it in my hands, I'm concerned. I have loupes with more glass than this lens has; it's not at all what I was expecting. Is this reasonable for a 4x5 wide angle lens? Will I get reasonable coverage and movement on 4x5? The camera hasn't arrived yet, so I'll have to wait a few more days to find out. In the meantime, you can help drive me crazy with more rumors and suppositions. What can you tell me about this lens I bought? Thanks. Mike. Since I don't know what you expected its hard to address that. The Angulon is a classic lens designed about 1929. It is a variation of a type known as a Dagor. A Dagor is a lens with three cemented elements in each cell. It is inherently a wide angle lens. While the powers of the cemented elements in the Angulon are different from a Dagor its properties are very similar. The outside elements of the Angulon are made oversize to avoid mechanical vignetting (or shadowing) by the lens mounting. The lens is also very slightly asymmetrical to improve its performance for distant objects. When the Angulon was first put on the market Schneider claimed a coverage angle of 102 degrees at infinity focus. The lens will indeed make a circle of light that big but the maximum coverage for good image quality is only about 90 degrees. A 90mm Angulon will cover a 4x5 negative with just a little left over. The original Angulon had a design defect. In fact, the design in the patent is defective and very early Angulons evidently followed it. These lenses have sever color fringing. Later Angulons (probably within a couple of years) evidently used a revised design which does not have this fault. I think (without looking) that this is actually a fairly late lens. More modern wide angle lenses have better performance than the Angulon but the price is large size and weight. The Angulon actually has very good performance. For maximum coverage it must be stopped down a lot, around f/45 for 90 degrees, it will operate well at f/22 for smaller coverage. Its used wide open only for composing the image. Some modern lenses employ a special design to reduce the fall off of light with angle, the Angulon is too old to have this design so its fall off is fairly severe. All "standard" design lenses fall off at a rate proportional to image angle that is cos^4 theta, where theta is the "half angle" that is the angular distance from the center of the image to the point of interest. For a 90mm lens covering 4x5 (diagonal of the film is 150mm) the angle is about 80 degrees and the fall off is such that the corner illumination is about one third that of the center. Richard Knoppow Los Angeles, CA, USA |
#3
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Newbie question: lenses
Ah, someone else like me who buys first and asks questions later. : - )
I believe this lens has an image circle of 154mm and an 81 degree angle of coverage (these numbers are taken from a secondary source, not from Schneider, so it's possible they're off a little). Since 161mm is about the size of the image circle required to cover 4x5 you won't get any movement to speak of with this lens. It just barely covers 4x5 when stopped down. However, many people happily use this lens for landscape work since movements often aren't necessary with that kind of work and its small size makes it ideal for backpacking. If you do architecture, product photography, or anything else that requires movements you probably should return the lens or buy a second one with room for more movements.. "MikeWhy" wrote in message om... Hi. I'm brand new to LF, and just bought my first camera and lens. I have a question about the lens, a Schneider Angulon 90mm f/6.8. I know it's old; the serial number is is mid 5 million, making it a two years my senior. The trouble is, I can't seem to find any information about it on the web. What I did find conflicted with everything else. I'm looking for just the angle of coverage and coverage at infinity focus. It was mere curiosity before; now that I have it in my hands, I'm concerned. I have loupes with more glass than this lens has; it's not at all what I was expecting. Is this reasonable for a 4x5 wide angle lens? Will I get reasonable coverage and movement on 4x5? The camera hasn't arrived yet, so I'll have to wait a few more days to find out. In the meantime, you can help drive me crazy with more rumors and suppositions. What can you tell me about this lens I bought? Thanks. Mike. |
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Newbie question: lenses
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#5
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Newbie question: lenses
MikeWhy wrote:
Hi. I'm brand new to LF, and just bought my first camera and lens. I have a question about the lens, a Schneider Angulon 90mm f/6.8. I know it's old; the serial number is is mid 5 million, making it a two years my senior. The trouble is, I can't seem to find any information about it on the web. What I Schneider is one company that provides a lot of info on the web. Others IMHO could learn from Schneider. http://www.schneideroptics.com/info/.../6,8-90mm.html Nick |
#7
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Newbie question: lenses
PS
Hi. I'm brand new to LF, and just bought my first camera and lens. I have a question about the lens, a Schneider Angulon 90mm f/6.8. I know it's old; the serial number is is mid 5 million, making it a two years my senior. The trouble is, I can't seem to find any information about it on the web. What I did find conflicted with everything else. I'm looking for just the angle of coverage and coverage at infinity focus. It was mere curiosity before; now that I have it in my hands, I'm concerned. I have loupes with more glass than this lens has; it's not at all what I was expecting. Is this reasonable for a 4x5 wide angle lens? Will I get reasonable coverage and movement on 4x5? The camera hasn't arrived yet, so I'll have to wait a few more days to find out. In the meantime, you can help drive me crazy with more rumors and suppositions. What can you tell me about this lens I bought? I might suggest getting one of these books as they might be helpful as you dive into large format User's Guide to the View Camera by Jim Stone Large Format nature Photography by Jack Dykinga Using The View Camera that I wrote a few years ago. All should be available from Amazon.com There is another book that some people suggest called View Camera Technique. As a reference this is very good. As a starter book it is a tome. steve simmons |
#8
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Newbie question: lenses
I believe this lens has an image circle of 154mm and an 81 degree angle of
coverage (these numbers are taken from a secondary source, not from Schneider, so it's possible they're off a little). Any thought of identifying your secondary source? It might be helpful to the questioner and to others who might have the same question if they new of a place to go look for this type of info. steve simmons |
#9
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Newbie question: lenses
Largformat wrote:
Subject: Newbie question: lenses From: "MikeWhy" Date: 1/31/2004 12:11 AM Mountain Standard Time Message-id: Hi. I'm brand new to LF, and just bought my first camera and lens. I have a question about the lens, a Schneider Angulon 90mm f/6.8. If you are going to be buying used lenses you might want to go back through issues of View Camera magazine. Over the years we've run articles on most of the lenses you will find out there. Or look here for some freely distributed information: http://www.graflex.org/lenses/lens-spec.html http://www.graflex.org/lenses/lens-faq.html http://www.graflex.org/lenses/photog...-tutorial.html http://www.hevanet.com/cperez/results.html http://www.hevanet.com/cperez/testing.html http://www.largeformatphotography.info/ http://www.bostick-sullivan.com/Alt_cameras/large format lenses.htm http://www.f32.net/Services/Equipmen...lensspecs.html http://medfmt.8k.com/mf/lflenses.html The angulon can be good or poor depending on the sample you end up with. Look at http://www.hevanet.com/cperez/results.html and see the variations in results from different samples. This is true of most lenses especially older ones. I would never buy a used lens (or new?) without some sort of "return if it's a dud" warranty. I'd consider the small size of the lens, whether you need movements and finally testing the sample you are send and decide if it might be useful. A SA has more coverage but is a MUCH larger and heavier lens. -- Stacey |
#10
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Newbie question: lenses
"BCampbell" wrote in message
.com... Ah, someone else like me who buys first and asks questions later. : - ) I'd been lurking here for about a month now, and noted the relatively low message volume. I absolutely didn't expect this gushing forth of on-topic information. Wow. :-) Thanks, guys. All of it was useful. |
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