About 4.5:1 magnification, f/4, 1 to 1 crop of a
single source image from above:
Good pixel-level detail for the magnification.
single source image from above:
Good pixel-level detail for the magnification.
Lens: Canon 35 mm f/2.8 bellows lens
Vintage: 1980's
Lens Mount: RMS mount
Needed Adapters: It is fairly easy to adapt an RMS mount to most camera bodies. I use a
Nikon to T-mount adapter and a T-mount to RMS adapter for this lens (the same adapter as
most microscope objectives use).
Nikon to T-mount adapter and a T-mount to RMS adapter for this lens (the same adapter as
most microscope objectives use).
Preferred Mounting: Normal (not reversed).
Filter Thread: None.
Controls: This lens has one control - the aperture setting.
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Resolution vs Aperture: This lens is at its
sharpest at f/4. For the focal length and expected
magnification range, the relatively large sharpest
aperture will provide sharp and detailed images.
The most detailed aperture is also f/4.
sharpest at f/4. For the focal length and expected
magnification range, the relatively large sharpest
aperture will provide sharp and detailed images.
The most detailed aperture is also f/4.
Corner Sharpness vs Aperture: There is a
minimal peripheral fuzziness seen at f/2.8. At all
apertures above this, the field is extremely flat,
less than 5% across the board.
This testing was performed at the minimum
bellows extension, about 2.6:1. These numbers
will tend to improve as the magnification
increases and worsen when the lens is mounted
directly on a camera.
minimal peripheral fuzziness seen at f/2.8. At all
apertures above this, the field is extremely flat,
less than 5% across the board.
This testing was performed at the minimum
bellows extension, about 2.6:1. These numbers
will tend to improve as the magnification
increases and worsen when the lens is mounted
directly on a camera.
Sharpness and Resolution vs Magnification:
This lens produces very sharp and detailed
images from a magnification of 1.3:1 to almost
7:1. Very few lenses will outperform this lens in
the lower magnification range.
At the high end of the magnification range,
shorter focal length lenses will tend to outperform
this lens. The increase in resolution with these
other lenses will come at the expense of shorter
working distance.
The corner sharpness is extremely good on a
bellows. This lens can also be used directly on
the camera although the corner sharpness
suffers a little at the lowest magnification. If you
mount it directly on a camera without extension,
you may benefit from stopping the lens down to
f/5.6 instead of f/4 to improve the corners.
This lens produces very sharp and detailed
images from a magnification of 1.3:1 to almost
7:1. Very few lenses will outperform this lens in
the lower magnification range.
At the high end of the magnification range,
shorter focal length lenses will tend to outperform
this lens. The increase in resolution with these
other lenses will come at the expense of shorter
working distance.
The corner sharpness is extremely good on a
bellows. This lens can also be used directly on
the camera although the corner sharpness
suffers a little at the lowest magnification. If you
mount it directly on a camera without extension,
you may benefit from stopping the lens down to
f/5.6 instead of f/4 to improve the corners.
Street Price: $250 - $500 in good used condition. Prices vary a lot online, shop around.
Chromatic Aberration: This lens show minimal color fringing in the center (about 0.10 - 0.20 pixel) and
mil/moderate on the periphery (0.010 - 0.084%). Anything below 0.04% is not considered significant. Above
0.08% is considered moderately visible. The moderately visible fringe is only seen at the highest
magnification. There is mild axial CA on out-of focus details (see image below) as shown by a slight red fringe
on the right and a slight green/cyan fringe on the left of the image.
mil/moderate on the periphery (0.010 - 0.084%). Anything below 0.04% is not considered significant. Above
0.08% is considered moderately visible. The moderately visible fringe is only seen at the highest
magnification. There is mild axial CA on out-of focus details (see image below) as shown by a slight red fringe
on the right and a slight green/cyan fringe on the left of the image.
Image Contrast: Image contrast is very good, typical for high-quality bellows lenses.
Flare: No significant flare is evident during lens testing.
Conclusion: This is a bellows lens that performs extremely well from 1.3:1 to about 7:1. The sharpness and
resolution are about as good as you will see from 1:3:1 to 3:1 and good to very good above that. That detail
does come with somewhat limited working distance, but more than adequate for most purposes. The field is
extremely flat at all except the lowest magnification (mounted directly on the camera, no extension). The
chromatic aberration is low to moderate, minimally visible at all but the highest magnification. The contrast is
good, typical for a bellows lens.
Overall this lens is hard to beat for a medium focal length bellow lens. It is commonly available on the internet
(used camera stores and eBay) for a moderate price (no higher than other bellows lenses). This lens has an
RMS mount which is easy to adapt to all camera bodies with a few commonly available adapters. there is little
not to like about this lens and I highly recommend it..
resolution are about as good as you will see from 1:3:1 to 3:1 and good to very good above that. That detail
does come with somewhat limited working distance, but more than adequate for most purposes. The field is
extremely flat at all except the lowest magnification (mounted directly on the camera, no extension). The
chromatic aberration is low to moderate, minimally visible at all but the highest magnification. The contrast is
good, typical for a bellows lens.
Overall this lens is hard to beat for a medium focal length bellow lens. It is commonly available on the internet
(used camera stores and eBay) for a moderate price (no higher than other bellows lenses). This lens has an
RMS mount which is easy to adapt to all camera bodies with a few commonly available adapters. there is little
not to like about this lens and I highly recommend it..
Basic Function: Requires a bellows for setting focus and magnification.
Appearance:
Aperture: 8 blades.
Image Samples:
About 2:1 magnification, f/4, focus stack of 17 images, resized
About 2:1 magnification, f/4, 1 to 1 crop of single
source image from above:
Very good pixel level detail.
source image from above:
Very good pixel level detail.
Performance: Sharpness vs Magnification:
I have 4 lines that represent levels of
performance from outstanding (top) to fair
(bottom). This shows where this lens fits into the
hierarchy that I have created.
The Canon 35mm shows sharpness performance
that varies from outstanding at the low-end to
good at the high-end of its magnification range.
I have 4 lines that represent levels of
performance from outstanding (top) to fair
(bottom). This shows where this lens fits into the
hierarchy that I have created.
The Canon 35mm shows sharpness performance
that varies from outstanding at the low-end to
good at the high-end of its magnification range.
Performance: Resolution vs Magnification:
I have 4 lines that represent levels of
performance from outstanding (top) to fair
(bottom). This shows where this lens fits into the
hierarchy that I have created.
The Canon 35mm shows resolution performance
that varies from outstanding at the low-end to fair
at the high-end of its magnification range.
I have 4 lines that represent levels of
performance from outstanding (top) to fair
(bottom). This shows where this lens fits into the
hierarchy that I have created.
The Canon 35mm shows resolution performance
that varies from outstanding at the low-end to fair
at the high-end of its magnification range.
About 4.5:1 magnification, f/4, stack of 26 images, resized:
