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Photography

  1. I love your lenses/loupes. Can I buy them from you?
  2. How old is my lens?
  3. What is the difference between angle of view and angle of coverage?
  4. Why does the size of the image circle in large format lenses change as the lens is stopped down?
  5. What is the Depth of Field of my lens if I know my Focal Length & Film Format Size?
  6. How do I get more depth of field?
  7. Why does the sharpness of my lens increase as I stop down, and decrease as I stop down further?
  8. When did Schneider begin multi-coating lenses?
  9. How can I tell if my lens is multi-coated?
  10. What is this MTF thing?
  11. My Schneider lens has a small protruding screw in the back of the shutter that prevents the lens from sitting flat against the lens board. What should I do?
  12. What is the correct order for stacking filters on a Super-Angulon lens?
  13. Which lens should I use for my application?
  14. I have an older Schneider convertible lens. How do I change between the focal lengths?
  15. What is a diopter?
  16. What Diopter value (power) do I need if I know my object distance (for close-up work)?
  17. What is hyperfocal distance?
  18. What is the Hyperfocal distance of my lens?
  19. How do I equate my 35mm format focal length to focal lengths in larger formats?
  20. Which aperture should I use when printing with my enlarging lens?
  21. Which focal length enlarging lens should I choose for my format?
  22. What is a Leica thread?
  23. What are the dimensions of your loupes?
  24. Do you have instructions for the Super Angulon 28/2.8 PC lens?
  25. What size filter do the Schneider PC-Tilt/Shift lenses take?
  26. Do Schneider lenses come with a Warranty?
  27. Where can I find the proper lens cap size for my Schneider lens?

1. I love your lenses/loupes. Can I buy them from you?

We are a distributor of Schneider products and don't sell direct to the end user (with the exception of parts). You can buy our products through any authorized Schneider lens dealer for lenses, loupes, and related products. Even if they don't have what you want in stock, they can order it for you.

Parts may be ordered directly from our service department. Contact:

NOTE: PHOTO LENSES AND LOUPES ARE DISCONTINUED.

 

2. How old is my lens?

We don't know. How old is it? You can look it up for yourself with our Age of Lenses chart.

 

3. What is the difference between angle of view and angle of coverage?

Angle of view is the angle that the lens sees. Angle of coverage is the angle that the film sees. Lenses are usually designed to project an image on the film plane that is larger than the film. With Large Format Lenses this is critically important, Since the concept of view cameras involves moving the film within the "image circle" projected by the lens.

 

4. Why does the size of the image circle in a Large Format lens change as the lens is stopped down?

Well . . . it doesn't actually. What actually happens is that when the lens is wide open, the center of the image is very bright and the corners of the image are VERY dark. So dark in fact that they do not expose the film (When the film is properly exposed for the center of the image). As the lens is stopped down, uniformity of illumination improves and therefore the circle of usable illumination increases.

 

5. What is the Depth of Field of my lens if I know my Focal Length & Film Format Size?

Depth of Field is is the distance between the nearest and farthest points in the object field that appear acceptably sharp in the photograph.
Depth of field varies with lens aperture, focal length, camera-to-subject distance, film format, print (or image) size and the distance from which that image is viewed. By definition, depth of field is dependent upon the viewer's perception of "acceptably sharp". If you make larger prints, or view them from a closer distance, depth of field is reduced. Make smaller prints, viewed from a distance, and DOF increases. There are standard values for the acceptable blur circle of a point that can be used to DOF. Those values will provide useful DOF information, except in extreme circumstances (like VERY large prints). We've made a DOF Calculation spreadsheet (requires Excel), using the standard blur circle values, that you can download here.

 

6. I'm photographing a small object, such as a diamond ring, full frame on 4x5 inch film and I cannot keep the entire object sharp even at small apertures. How do I get more depth of field?

There are no magic lenses that can get you more depth of field. Large format close-up and macro photography is difficult and depth of field is always an issue. Finding a solution requires compromises. If you stop your lens down to very small f-stops to increase the depth of field, you will suffer from a loss of overall sharpness due to diffraction. Of course, you can use the swings and tilts of your view camera to control where you put the plane of sharp focus in your image. This may help. Otherwise your best option may be to reduce the size of your image. Depth of field will then increase. One technique that might be useful is to use a shorter focal length lens. This will increase the depth of field. The resulting negative can then be printed and cropped to achieve the desired final image size. Unfortunately this will result in some quality loss due to the increased enlargement of the negative.

 

7. Why does the sharpness of my lens increase as I stop down, and then decrease as I stop down further?

You are experiencing the effects of two primary optical aberrations, spherical aberration and diffraction. As you stop the lens down, spherical aberration is reduced, and the effects of diffraction are increased. This generally results in a "sweet spot" around f11, where the image has benefited from reduced spherical aberration, but not yet been degraded severely by diffraction. At small apertures such as f64, diffraction effects are quite large and the image will be noticeably softer.

 

8. When did Schneider begin multi-coating lenses?

The first Symmar-S lens to be multi-coated was the Symmar-S 150mm, serial number 13,014,862 in March 1977. The 210mm followed and then the rest of the focal lengths were completed by early 1978. The Super-Angulons were multi-coated in the summer of 1978 beginning with the f/5.6 series. The f/8 lenses were multi-coated in late '78- early '79. Apo-Componon HM lenses have been multi-coated since their introduction in 1986.

 

9. How can I tell if my lens is multi-coated?

If your lens says "multi-coating" on it, then it has a multi-coating. If your lens does not have this designation, then it does not have a multi-coating on it.

 

10. What is this MTF Thing?

MTF stands for Modulation Transfer Function. There are several different types of MTFs, but they are all a method of determining the ability of a lens to faithfully reproduce an object on film. For a more in-depth discussion of lens quality evaluation methods go to: https://www.schneideroptics.com/pdfs/photo/quality.pdf

 

11. My Schneider lens has a small protruding screw in the back of the shutter that prevents the lens from sitting flat against the lens board. What should I do?

In order to prevent the lens from rotating in the lens board, a hole can be drilled into the lens board to accommodate this screw. Once the screw is mated to this hole, the lens will stay in one orientation. The screw can also just be removed with no ill effects on the performance of the lens.

 

12. What is the correct order for stacking filters on a Super-Angulon lens?

The center filter for the Super-Angulon is designed to modify the brightness distribution in a specific way so it should be the first filter to be screwed onto the lens. Other filters can be screwed to the center filter but to avoid vignetting, use Slim filters only. Keep in mind that the center filter uses a larger accessory thread than the lens, so you will need a larger filter than what would fit directly on the lens. Since Slim filters have no front threads, stacking two filters on top of the center filter will require a regular filter and a Slim filter. This combination shouldn't vignette as long as no extreme movements are used.

 

13. Which lens should I use for my application?

It all depends on what you are trying to do. Landscape photographers would want high resolution and not a lot of movement, so an Apo-Symmar or Super-Symmar XL would be a good choice. Architectural photographers need lots of movement, so a Super-Angulon lens would be a good lens to use. Product photographers would find the G-Claron useful whether shooting large products or a table top setting. The Macro-Symmar is needed for photographing smaller items or jewelry. Of course, many lenses can pull double duty; there's no reason why a Super-Angulon couldn't be used for landscapes and Apo-Symmars for architectural shots of buildings that don't require a lot of tilt and shift. Many field photographers choose the G-Claron lenses because they are compact and are capable of producing excellent images at infinity.

 

14. I have an older Schneider convertible lens. How do I change between the focal lengths?

With the lens put together, it operates in the short focal length mode. By removing the entire front element (everything in front of the shutter), the lens is converted into the long focal length mode. In this configuration, use the green scales on the shutter to determine f/stop. Removing half the lens from the system affects the lens's ability to correct for aberrations. The long focal length mode is perfect for portraits, as the edges of the image will exhibit softness. In the short focal length mode (both lens elements in place), the lens will behave like a non-convertible lens in terms of quality and specifications.

 

15. What is a diopter?

There are two answers to that question. In common photographic usage, diopter is synonomous with "close up lens". A standard close-up lens is a single element lens that screws into the accessory thread of your camera lens, like a filter. These lenses allow you to photograph small objects, close up. The strength of close up lenses is measured in diopters. Common values are +½, +1 and +2. For high quality work, you probably won't want to use a diopter stronger than +3. The second and technically more accurate answer to your question is that diopter is a measure of lens power, often used regarding opthalmic (eyeglass) lenses. A lens with a power of 1 diopter has a focal length of 1 meter. Close up lenses are marked as "+1 diopter", for example, so they've come to be known as "diopters", in common usage.

 

16. What Diopter value (power) do I need if I know my object distance (for close-up work)?

Use our Close-Up Lens Calculator worksheet (requires Excel), available for download here.

 

17. What is hyperfocal distance?

Depth of field is the zone of acceptable focus in front of and behind the point of best focus. If a lens is focused at infinity, the depth of field beyond the focus point (beyond infinity) is wasted. For a particular lens, aperture and film format size, the depth of field can be maximized by focusing the lens at the hyperfocal distance. The hyperfocal distance is the point of focus chosen so that the depth of field extends from a near point to infinity. As you stop down the lens, the depth of field increases and therefore the hyperfocal distance is closer to the camera.

 

18. What is the Hyperfocal distance of my lens?

That depends on the lens focal length, film format size and lens aperture you are using. You can use our Depth of Field Calculator spreadsheet (requires Excel) to calculate hyperfocal distance for your various requirements. The DOF Calculator can be downloaded here.

 

19. How do I equate my 35mm format focal length to focal lengths in larger formats?

You can equate your 35mm format focal length to focal lengths in larger formats with our Lens Conversion Chart.

 

20. Which aperture should I use when printing with my enlarging lens?

Changing the aperture setting on your enlarging lens has the same effect as changing the aperture setting on your camera lens. Closing down 2 stops from wide-open is a good way to have a decent depth of field as well as keeping exposure times reasonable. If you'll be dodging and burning, close down more and increase your exposure time. This will make the transition from burned area to dodged area more gradual. Small apertures will introduce diffraction which can affect sharpness, so only use apertures like f/16 and f/22 if you really need it.

 

21. Which focal length enlarging lens should I choose for my format?

There is no set focal length that works for a specific format -- a range of focal length lenses are usually suited to a format. For 35mm negatives, try a Componon-S 50 or an Apo-Componon 40. Medium format negatives work well in the range of 60 to 100mm lenses, depending on the specific negative size. 4x5 negatives require nothing shorter than a 135mm lens, although 150mm is the "standard" size. 8x10 shooters would do well with the Componon-S 240 or the G-Componon 300 or 360.

 

22. What is a Leica thread?

In 1931, Leitz introduced a thread-mount of 39mm x 26tpi (threads per inch) for its Leica cameras. This combination of a metric diameter with an English imperial pitch was designed in order to forestall competition from aftermarket lenses being used with the Leica screw-mount rangefinder cameras. Although it was patented in the same year, other companies pirated the design and introduced lenses with the new 39mm thread.

Presumably in their haste to introduce their own products with the Leica thread, some rival companies did not take the time to verify that the Leica thread's pitch was indeed 26 threads per inch. They came out with products that used a metric pitch instead. These "almost" Leica thread lenses would bind to true Leica mounts (if forced.) For this reason, Leica thread lenses (not made by Leica) should be GENTLY screwed into their mounts. If resistance is felt, they should not be forced.

At the same time, Leitz also marketed enlargers with the Leica thread in order to allow the use of solid 3.5/3.5cm Leitz Tessar taking lenses as enlarging lenses. By mid-decade, Zeiss Ikon offered enlargers which used the Leica thread and other companies followed suit. Eventually, the Leica thread became one of the standard mounts in the enlarger industry.

 

23. What are the dimensions of your loupes?

Please consult this PDF of Loupe Technical Data.

 

24. Do you have instructions for the Super Angulon 28/2.8 PC lens?

Please consult this PDF of the User Manual.

 

25. What size filter do the Schneider PC-Tilt/Shift lenses take?

The Schneider PC-Tilt/Shift lenses have a filter thread of 95mm x 1.0
For more information, please consult this PDF of the User Manual.

 

26. Do Schneider lenses come with a Warranty?

Schneider lenses are warranted by Schneider Optics, Inc. (Schneider) to be free of defects in material and workmanship for a period of one (1) calendar year from the original purchase date. During this period Schneider will repair without charge any lens which is found to be defective in material or workmanship.

For more information, click here.

 

27. Where can I find the proper lens cap size for my Schneider lens?

Please refer to our price list for all available lens cap sizes.