new 150mm flat-field lens or general purpose lens: which is most versatile for my needs?greenspun.com : LUSENET : Large format photography : One Thread
i am thinking about buying a 150mm lens to use on my toyo field camera (the 45a). i am having trouble deciding between three categories: 1.) a flat-field close up lens like the schneider g-claron (around $500), or 2.) a mid-priced general-purpose lens like the nikkor w, the rodenstock apo sironar n, or the schneider apo symmar ($550-670), or 3.) a higher-priced lens that might, for all i know, combine the best of the first two categories in spite of what they are specifically designed for, like the nikkor apo macro, the rodenstock apo sironar s, or the schneider super symmar (i know these last 3 have very different purposes).
i shoot many full-frame pictures (both professionally and for pleasure)of flat things like paintings that range in size from 5 inches long to 100 inches long, and for this it seems that the g claron is the best choice, or something of a similar design. but i also shoot just as many pictures of things that are farther away and not flat. i understand the g claron can give decent (but still not top-quality) results for lower magnifications if stopped down to f 22. but i would rather have a general purpose lens if it could give top-quality results close-up on flat things.
I know that no lens can be designed to do everything. so maybe i should just buy both a g claron and something from category 2 above. but I'm wondering which of these categories (1 or 2 or 3) is least up to the challenge of shooting subjects it was not designed for at magnifications it was not designed for: for example, which is worse on a 4 x 5 camera? the g-claron shooting a distant landscape at f22, or a nikkor w shooting a 5-inch (or 100-inch) flat painting full-frame? as i understand it, anything more than 25 inches long would be longer (if shot full-frame with a 4 x 5) than what the g-claron is best for. at magnifications less than this, is a nikkor w just as good as a g-claron for shooting flat paintings? only at certain apertures? would the expensive super symmar or sironar-s give me better results of this than the nikkor w? schneider's tech people tell me that the g claron is actually more versatile than any of these, if i just stop down to f22. but if the g claron is the best all around lens for all these things, why would it also be the least expensive? (stupid question, i know. but still...)
by the way, i have carefully read (although not entirely understood)this article on flat field lenses by ron wisner: http://www.wisner.com/myth.htm it is good, but all it tells me is not to worry about the g claron for general purpose. but can someone tell me not to worry about the nikkor w (or apo sironar s, or something else) for close-up pictures of flat things?
it would be nice to have just one 150mm do all these things well, (and fit inside my toyo 45a when i fold it up!) so that i do not have to buy (and carry around) two 150mm lenses.
i know some of you will be thinking i should learn more with cheaper equipment before i spend all this money on a new 150. i do not deny that i have a lot to learn about 4 x 5 photography. i've only spent about a year in earnest doing it, and that has been in the studio with older equipment. but i did comit my life to being a photographer twelve years ago, and have been living and breathing photography (mostly small and medium format) ever since, without looking back. so i know i am in this for the long haul both professionally and for pleasure, and am not hesitating to make the investment in a really good 150 lens (i've been using a 150 schneider symmar whose shutter started giving me problems recently... many of you very generously gave me advice about how to handle that situation, and i thank you. i finally decided to look into better lenses rather than spend any money on a toyo lens board for it or on repairs for it).
sorry so long-winded. any thougts from you are greatly appreciated.
-- Mark Woods (email@example.com), May 17, 2000
I would go with the G-claron. It is fine at infinity when stopped down, but a lens optimized for 1:20 will not perform well at close distances.
-- William Marderness (firstname.lastname@example.org), May 17, 2000.
Since you mentioned that you will shooting a lot of flat objects, go with the G-Claron or any other similar process lens - it will perform better than the non-copy/process types at less than 1:5.
It's a fallacy that the G-Clarons (or process lenses) do not do as well as other non-process lenses at infinity. You just have to be sure to stop down to f22. Consider the fame of the assorted Goerz Artars and APO Ronars. These are all process lenses.
Chris Perez and K Thalmann has some tests which includes the same 150mm f9 lens you're thinking of: http://www.hevanet.com/cperez/testing.html
Look at the results of the other process lenses (Kowa Graphics, e.g.). Results are similar - they are superb performers for distant objects as long as they properly stopped down.
I own a 240mm G-Claron that I use professionally and can testify that its a superb lens. Tack sharp, contrasty (despite the single coating), and most importantly, very low distortion. About the only annoying thing is that a f9 lens in dark places can be hard to focus. G-Clarons are really terrific value IMO.
FWIW, the old Symmar that you are using isn't half bad for copy work. It's a lot more symmetrical than the later Symmar models (S, APO) that succeeded it.
-- K H Tan (email@example.com), May 18, 2000.
I have a 150 G Claron and find it an excellent all around lens. I shoot a lot of flat surfaces also, but mostly in the field (vine covered walls, sides of barns, etc.). It works well at all distances. For close up work, you will be hard pressed to find a general purpose lens that won't leave your corners out of focus. You can overshoot your subject and then crop in the print, but that is a pain, especially if you are using a gg and can't see your corners. You can also spend a half hour on each shot making precise depth of field calculations trying to compensate for lens curvature, but you usually wind up with everything slightly out of its sharpest focus. I have used the Claron for close up work on sculptural objects and easily get everything in focus. I also shoot a lot of landscapes, and if I want a normal focal length (150mm) I use the Claron. The only problem with this and other flat field lenses is with astigmatism. I don't quite understand the technical details myself, but what it means in practice is there is a sharp drop-off in focus from the plane of sharpest focus. You have to be careful, especially with close-up flat surfaces, that your plane of focus is parallel to you subject. When using movements it gets a little more difficult. Tilts, shifting the plane of focus, will change the anastigmatic point, and will usually throw the focus way off at the edges. You need to use one of the enhanced focusing screens so that you can see the whole image. General purpose lenses are probably better when using movements, but the Claron will work almost as well if you are careful. But even with these disadvantages, I use the Claron as my workhorse lens.
-- John Laragh (firstname.lastname@example.org), May 18, 2000.
You asked a lot of questions. I will try to answer some.
The G-Claron does well at all distances, from closeups to landscapes. Other advantages are its reasonable price and light weight.
But no lens is perfect. The disadvantages of the G-Claron are its slower speed, single-coating, and smaller coverage. The slower speed means a dimmer image for composing. The lens is single-coated rather than multi-coated and so will be more prone to flare. You can fight this by shading the lens from bright light outside the image. The 150 mm G-Claron has an image circle of 189 mm (infinity and f22), which will allow rise/shift movements of 21/25 mm for a 4x5 negative. As an example of what other plasmats can do, the 150 mm Apo-Symmar has an image circle of 220 mm and permits rise/shift of 39/44 mm.
I have done some experiments with "normal" non-closeup lenses for closeups. One compared a G-Claron with a Fujinon-W for an image that was about 1/3 lifesize. The Fujinon-W could only be focused using the central 1 inch of the image because the rest was very soft. However, stopped down to a reasonable taking aperture it produced a sharp image. The negatives from the G-Claron and Fujinon-W were virtually indistinguishable. I judged the Fujinon-W negative to be _very_ slightly sharper. For a lifesize image, the results might very well be different (i.e., more favorable to the G-Claron).
The Rodenstock Apo-Sironar S is said to perform well over a wider range of image sizes than most of the plasmats designed for landscape work. I haven't done any tests as such. I have found it to do very well for table-top scale images. Wide-open, the ground glass image is useable for focusing (unlike the Fuji). I haven't tried it for 1:1.
No lens is optimum for all of the tasks that you mention. If you are only going to buy one lens, you will have to decide which criteria are most important to you. You could always buy one lens now, and later another one. The primary disadvantage of the 150 mm G-Claron would be the limitations on movements for distant shots. If you got a lens designed for distances, it would probably work well up to 1:5 or more, depending on the lens, but probably would be poor at 1:1. If the object you are photographing is too small for the lens to fill the 4x5 image area, you could also use fine-grained film and enlarge more. Wasting a little film area is much cheaper than a lens!
You might want to consider a focal longer than 150 mm, perhaps 180 or 210 mm. I prefer 180 mm as my normal lens. This will give you more coverage and also more space between the lens and object when doing closeups. However, if you want to be able to go to 1:1, you need to check the bellows draw on your camera.
-- Michael Briggs (MichaelBriggs@earthlink.net), May 21, 2000.