• Ultraviolet Photography
  •  

Canon 50mm f/3.5 FDn Macro

Lens
11 replies to this topic

#1 UlfW

    Ulf W

  • Members+G
  • 1,739 posts
  • Location: Sweden, Malmö

Posted 23 March 2021 - 12:06

Last Update: 03 April 2021 agb/label/spacing
Finalized: Work in progress.

Canon 50mm f/3.5 FDn Macro

Manufacturer: Canon
Lens Label: CANON MACRO LENS FD 50mm 1:3.5
Currently manufactured: Yes

Lens type: Manual focus, Prime, close focussing macro lens
Design: 6 elements in 4 groups
Attached Image: Screen Shot 2021-03-23 at 11.44.07 copy.png
Focal length: 50mm
Aperture range: f/3.5 – f/32, 6 blades, can be locked for manual stopped down mode
Magnification range: to 0.5x at 0.232m. Up to 1x with the Extension Tube FD25-U that the lens originally were delivered with
Sensor format/coverage: up to 24 mm x 36 mm
Mount: Canon FD
Flange Focus distance: FD-standard, 42.00mm
Front filter: 52 mm x 0.75 mm
Introduction year: 1979.
This is likely the same lens-type as the older version: Canon Macro Lens FD 50mm f/3.5 S.S.C. introduced 1973
S/N of test object: 161623

Lens info on the web: http://www.mir.com.my/rb/photography/companies/canon/fdresources/fdlenses/fdmacro/50macro.htm


Image of test object:

Attached Image: IMG_2730.jpg Attached Image: IMG_2731.jpg Attached Image: IMG_2732.jpg

Attached Image: IMG_2733.jpg

Transmittance Summary

Definitions of the parameters below
  • Range: The Canon 50mm f/3.5 Macro FDn lens transmits 1-70% in an increasing slope from 336nm to 400nm.
  • TVISmax (%) = 93%
  • T400nm (%) = 70%
  • T365nm (%) = 49%
  • λUV HMvis(nm) = 363nm
  • λUV HM400(nm) = 356nm
  • λUV Zero(nm) = 336nm
    These three values indicate that the lens is only working for UV-A photography.

Spectral Transmission Graphs

UV-NIR, Canon 50mm f/3.5 Macro FDn

The transmission measurement accuracy into the end of NIR range is less good due to limitations in the light source.

UV, Canon 50mm f/3.5 Macro FDn


UV-Log, Canon 50mm f/3.5 Macro FDn

Numerical Spectra Data available: Yes

General comments about the UV-reach:
This lens do not reach very deep into UV, but many times this reach will be enough for most UV-photography, with sun or UV-converted flash as light source, together with a typical UV-pass filter-stack or a Baader U.
A good enlarger lens like a EL-Nikkor 80mm old metal or a suitable Focotar 50mm is definitely better with their deep UV-reach, but they demand more effort getting a suitable helicoid, mount adapter and arrange for mounting the UV-pass filters.

Filters and how to use them on this lens:
The front filter thread is 52mm standard filter thread.

It is also possible to use rear mounted filters, either in lens mount adapters for mirrorless cameras like Sony A-series etc, or placed directly in the camera.

An alternative, if space in the camera allows, is to putty-mount a filter directly against the lenses rear surface, that provides a good reference plane for orienting the filter normal to the optic axis.
The rear lens element is not recessed and thus needs a filter mounted in a filter ring to place the filter's glass surface at a safe distance from the rear lens element.


Handling and focussing:
Due to the short 42mm flange focus distance this lens will not focus at infinity on some DSLRs.
It is still an excellent lens for closeup due to the built in focussing helicoid.

There are cheap well working lens mount adapters for the FD mount for several mirrorless cameras like Canon M, Sony NEX mount etc.
I used this lens as my main 50mm lens during the film era with several different FD-mount cameras. It is an excellent lens in general.

Sharpness:
High according to several sources. I agree.

Lens distortion:
TBD

Chromatic Aberration in UV:
TBD

Image samples:

Attached Images

  • Attached Image: Screen Shot 2021-03-19 at 12.43.47.png
  • Attached Image: Screen Shot 2021-03-19 at 12.44.35.png
  • Attached Image: Screen Shot 2021-03-19 at 12.43.15.png

Ulf Wilhelmson
Curious and trying to see the invisible.

#2 Stefano

    Member

  • Members(+)
  • 2,066 posts
  • Location: Italy

Posted 23 March 2021 - 13:29

Not bad for a modern lens! Goes below 340 nm.

Why is the front element so deeply recessed?

#3 dabateman

    Da Bateman

  • Members+G
  • 2,925 posts
  • Location: Maryland

Posted 23 March 2021 - 13:49

View PostStefano, on 23 March 2021 - 13:29, said:

Not bad for a modern lens! Goes below 340 nm.

Why is the front element so deeply recessed?

Thats a common macro lens design. It allows for it to more forward more for greater magnification in a smaller package.

#4 UlfW

    Ulf W

  • Members+G
  • 1,739 posts
  • Location: Sweden, Malmö

Posted 23 March 2021 - 14:25

View Postdabateman, on 23 March 2021 - 13:49, said:

Thats a common macro lens design. It allows for it to more forward more for greater magnification in a smaller package.
It also improves contrast and flare as it acts as a lens shade.
Ulf Wilhelmson
Curious and trying to see the invisible.

#5 UlfW

    Ulf W

  • Members+G
  • 1,739 posts
  • Location: Sweden, Malmö

Posted 23 March 2021 - 14:28

View PostStefano, on 23 March 2021 - 13:29, said:

Not bad for a modern lens! Goes below 340 nm.
Only with very little transmission, around 3% at 340nm, but still usable in the context I described in the main post.
I got two of them to have one spare, as I like the lens very much.

Edited by UlfW, 23 March 2021 - 14:30.

Ulf Wilhelmson
Curious and trying to see the invisible.

#6 Bill De Jager

    Member

  • Members
  • 311 posts
  • Location: Northern California, USA

Posted 23 March 2021 - 18:36

I have the FL 50mm f/3.5 which I've never tested. It has a simpler formula with 4 elements in 3 groups. It's also sufficiently older than the FDn version to probably have very different and simpler coatings.
Studying the botany and plant geography of California and western North America for almost 50 years.

#7 UlfW

    Ulf W

  • Members+G
  • 1,739 posts
  • Location: Sweden, Malmö

Posted 23 March 2021 - 19:58

View PostBill De Jager, on 23 March 2021 - 18:36, said:

I have the FL 50mm f/3.5 which I've never tested. It has a simpler formula with 4 elements in 3 groups. It's also sufficiently older than the FDn version to probably have very different and simpler coatings.
That type of lens would be interesting to test and measure, but I am trying to resist buying more lenses now as I had some high expenses lately.
On eBay there are one to a very reasonable price.
https://www.ebay.co....er/154227788557
To get it here the cost will be doubled due to shipping VAT and customs fees.
As the only use I would have for it would be to measure it I'll pass.
Ulf Wilhelmson
Curious and trying to see the invisible.

#8 Bill De Jager

    Member

  • Members
  • 311 posts
  • Location: Northern California, USA

Posted 24 March 2021 - 20:09

I managed to try out the Canon FL 50/3.5 today and it certainly works in UV, showing the characteristic UV signature in Taraxacum. More later as I need to redo my work. Lots of trial and error here.
Studying the botany and plant geography of California and western North America for almost 50 years.

#9 colinbm

    Member

  • Members+G
  • 2,610 posts
  • Location: Australia

Posted 25 March 2021 - 03:41

Are there any AF lenses that are useful for UVA photography other then the M4/3 30mm lens ?

#10 UlfW

    Ulf W

  • Members+G
  • 1,739 posts
  • Location: Sweden, Malmö

Posted 25 March 2021 - 04:06

View Postcolinbm, on 25 March 2021 - 03:41, said:

Are there any AF lenses that are useful for UVA photography other then the M4/3 30mm lens ?
https://www.ultravio...0mm-f28-ef-stm/
Ulf Wilhelmson
Curious and trying to see the invisible.

#11 dabateman

    Da Bateman

  • Members+G
  • 2,925 posts
  • Location: Maryland

Posted 25 March 2021 - 04:36

View Postcolinbm, on 25 March 2021 - 03:41, said:

Are there any AF lenses that are useful for UVA photography other then the M4/3 30mm lens ?
Not the best place for this question. Especially since most macro lenses are poor at Autofocus.

I was trying to compile a list here:
https://www.ultravio...or-all-systems/

But my favorite is the Canon 40mm STM which can be adapted to most cameras now. Even your new Fp with the Sigma MC-21 EF-L mount adapter.

Edited by dabateman, 25 March 2021 - 04:38.


#12 colinbm

    Member

  • Members+G
  • 2,610 posts
  • Location: Australia

Posted 25 March 2021 - 06:11

Thanks Ulf & Dave
Yes it is for the Sigma fp.
I will go with this EF40mm, it'll take a few weeks.
I have trouble with focusing the manual M42 lenses, so that is why I am looking at a auto-focus, UVC capable lens. The only way I have been able to get sharp images is to "focus stack' & select the best or merge them into a stacked image.
I need to look at a larger screen, external monitor, that is in real time with the camera. I see that they use an external monitor in cine mode, but I haven't had anyone tell me if it will work in stills mode ?