Canon 50mm f/3.5 FDn Macro

[ulf]

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: No

 

Lens type: Manual focus, Prime, close focussing macro lens

Design: 6 elements in 4 groups

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:

 

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.
• T_VISmax (%) = 93%
• T_400nm (%) = 70%
• T_365nm (%) = 49%

• λ_{UV HMvis}(nm) = 363nm
• λ_{UV HM400}(nm) = 356nm
• λ_{UV 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.

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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.

 

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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

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Image samples:

 

 

 

[Stefano]

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

 

Why is the front element so deeply recessed?

[dabateman]

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.

[ulf]

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]

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.

[Bill De Jager]

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.

[ulf]

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.

[Bill De Jager]

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.

[colinbm]

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

[ulf]

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

https://www.ultravioletphotography.com/content/index.php/topic/4378-canon-40mm-f28-ef-stm/

[dabateman]

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.ultravioletphotography.com/content/index.php/topic/3397-list-of-uv-capable-af-lenses-for-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.

[colinbm]

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 ?

[ulf]

Corrected the Manufacturing status typo to No.

(copy paste error)

 

Thanks Stefano for noting the error.