- I love your lenses/loupes. Can I buy them
- How old is my lens?
- What is the difference between angle of
view and angle of coverage?
- Why does the size of the image circle in
large format lenses change as the lens is stopped down?
- What is the Depth of Field of my lens if I know my Focal
Length & Film Format Size?
- How do I get more depth of field?
- Why does the sharpness of my lens increase
as I stop down, and decrease as I stop down further?
- When did Schneider begin multi-coating
- How can I tell if my lens is multi-coated?
- What is this MTF thing?
- 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?
- What is the correct order for stacking
filters on a Super-Angulon lens?
- Which lens should I use for my application?
- I have an older Schneider convertible
lens. How do I change between the focal lengths?
- What is a diopter?
- What Diopter value (power) do I need if I know my object
distance (for close-up work)?
- What is hyperfocal distance?
- What is the Hyperfocal distance of my lens?
- How do I equate my 35mm format focal length to focal
lengths in larger formats?
- Which aperture should I use when printing with my enlarging lens?
- Which focal length enlarging lens should I choose for my format?
- What is a Leica thread?
- What are the dimensions of your loupes?
- Do you have instructions for the Super Angulon 28/2.8 PC lens?
- What size filter do the Schneider PC-Tilt/Shift lenses take?
- Do Schneider lenses come with a Warranty?
- Where can I find the proper lens cap size for my Schneider lens?
1. I love your lenses/loupes. Can I buy them from
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
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
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
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.