Saturday 2 August 2014

Minolta MD Rokkor 50 mm 1:1.4 with Focal Reducer [MD]

Since I've got my Focal Reducer, I used all my lenses with it. Recently I've found a bargain Minolta MD Rokkor 50 mm 1:1.4 with a little bit of fungus. It doesn't affect photos at all and the price was good. So I decided to buy it, when realised there are no MD adapters allowing focusing infinity. As I like to use my lens in any given condition, I designed and printed my own adapter.

Minolta MD Rokkor 50/1.4 on Lumix G2 (MFT camera) with Focal Reducer.
Minolta MD Rokkor 50/1.4 on Lumix G2 (MFT camera) with Focal Reducer.

Minolta MD>Canon EOS EF adapter

When I bought the lens I wasn't aware that there are MD>EF thin adapters, so I decided to pint one myself. I downloaded Minolta lens cap by profhankd from Thingiverse and EF Mount Module by AlexEnglish also from Thingiverse. Then I created MD>EF adapter with 0.2 mm thick flange (became thicker in printing process). It would be perfect to remove that flange at all, but it's a place to cut a hole to lock the lens on Canon camera or Focal Reducer. Otherwise, one must drill a hole in the lens, which I wanted to avoid (collector value).
3D-print-ready Minolta MD>Canon EF thin adapter model - perfect for Focal Reducer.
3D-print-ready Minolta MD>Canon EF thin adapter model - perfect for Focal Reducer.
3D-print-ready Minolta MD>Canon EF thin adapter model - perfect for Focal Reducer.
3D-print-ready Minolta MD>Canon EF thin adapter model - perfect for Focal Reducer.

All you have to do is to print it. I printed 0.1 mm layer thickness and no support - worked perfectly. Photos show adapter printed in black and red, because black filament jammed in the printer and I had to change it. It doesn't affect the quality at all.
Then I cut hole in adapter for EF mount lock - simply with scissors. I didn't modelled the hole, because I wanted it to fit tight with Focal Reducer.
Minolta MD Rokkor 50/1.4 with thin MD>EF adapter - EF mount lock cut out visible.
Minolta MD Rokkor 50/1.4 with thin MD>EF adapter - EF mount lock cut out visible.
Then I drilled a hole to place the screw locking MD lens (visible on the photo below). The screw and the nut came from my spare parts box and I don't know any dimensions of it.
Minolta MD Rokkor 50/1.4 with thin MD>EF adapter - lens locking screw visible on the photo.
Minolta MD Rokkor 50/1.4 with thin MD>EF adapter - lens locking screw visible on the photo.
All in all, the adapter works great. It doesn't work with bare EF mount, due to the fact that flange distance is a bit too long (about 0.5 mm). However, Focal Reducer gives you the opportunity to correct it with internal optical element. Now the lens focuses infinity and that's awesome!

Minolta MD Rokkor 50/1.4 with thin MD>EF adapter and Lumix G2 with Focal Reducer.
FR internal optical element visible on the photo - that's the one to be adjusted.
Finally proof of infinity focus. There were no clouds that day, but lens focused even a bit beyond those trees.

Minolta MD Rokkor 50/1.4 with EF Focal Reducer - infinity focus @2.0

Bokeh and depth of field

As the lens is very fast, designed for full frame and used with focal reducer the depth of field is very shallow @1.4.

Minolta MD Rokkor 50/1.4 with Focal Reducer - @1.4 - focused as close as possible.
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @1.4 - focused as close as possible.
Minolta MD Rokkor 50/1.4 with Focal Reducer - @1.4.
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @1.4.
Minolta MD Rokkor 50/1.4 with Focal Reducer - @1.4.
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @1.4.
Minolta MD Rokkor 50/1.4 with Focal Reducer - @1.4.
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @1.4.
Adjusting the aperture allows you to correct aperture by 1/2 f-stop from 1.4 to 16. Samples below show how various outcomes can be achieved with different settings.

Minolta MD Rokkor 50/1.4 with Focal Reducer - @1.4
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @1.4
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @2.0
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @2.0
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @2.8
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @2.8
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @4
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @4
Minolta MD Rokkor 50/1.4 with EF  Focal Reducer - @5.6
Minolta MD Rokkor 50/1.4 with EF  Focal Reducer - @5.6
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @8
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @8
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @11
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @11
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @16
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @16

Minolta MD Rokkor 50/1.4 with EF Focal Reducer - f1.4-16 animation
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - f1.4-16 animation

Lens flare

It was a very sunny day with light clouds that changed rapidly. I've tried to capture flaring a few times and only one set of photos was good enough to be published.
Flaring exists, when aimed directly at the sun and was quite strong at low aperture values.

Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @16
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @16
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @11
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @11
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @8
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @8
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @5.6
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @5.6
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @4.0 - highly overexposed, yet some flaring visible in left corner.
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @4.0 - highly overexposed, yet some flaring visible in left corner.
Flare shape is quite pleasant I must admit and might be an advantage for those seeking for that kind of solution.

Image quality

I myself found image quality very close to Olympus Zuiko MC Auto-S 50/1.8 with Focal Reducer, however Minolta 50/1.4 gives you that a bit faster aperture. It's perfectly usable and sharp @1.4, but if you prefer a top-notch sharp image, just go down to f2.8 and you're there.
Finally, a few more samples to take a glimpse at.

Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @1.4
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @1.4 - architectural detail
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @2.8
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @2.0 - architectural detail
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @2.8
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @2.8 - architectural detail
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @1.4
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @1.4
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @2.0
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @2.0
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @2.8
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @2.8
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @4.0
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @4.0
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @5.6
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @5.6
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @8.0
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @8.0
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @11
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @11
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @16
Minolta MD Rokkor 50/1.4 with EF Focal Reducer - @16

Conclusion

I'm very satisfied with Minolta MD Rokkor 50 mm f1.4. Concerning the bargain price I got it for, it is a real gem. Although I can't compare Focal Reducer setting to plain adapter configuration, it's working really well.
The 3D-printed adapter works like a charm, although I have replaced the lens a lot. It's still firm and solid, holding the lens in place. It doesn't allow infinity focus with normal EF>MFT adapter. There might be need to remove or file a bit that tiny flange.

3 comments:

  1. Hi

    Thanks for the write up, which is quite useful to me.

    I am considering the thin adapter available on eBay to go with an EF focal reducer and 50mm 1.4 minolta lens (which I already have). I'm just concerned about the infinity focus, even with adjusting the elements in the FR. Is there a lot of range? Have you been able to use this combination with infinity focus on wider lenses as well?

    I'm just trying to get a sense of how much margin there is.

    Thanks

    ReplyDelete
    Replies
    1. Hi!
      Thanks for nice words - it's always encouraging to publish more tests :)

      I wasn't sure about the MD-EF adapter that's available in retail. The flange distance of both mounts is very, very close and even my adapter needs slight adjusting. I'm not sure what's going to happen when you get thicker one.

      On the other hand, those shouldn't be extremely expensive on eBay, so maybe it's worth a try :)
      Cheers!

      Delete
  2. Hi!

    Many thanks for the post - most likely I'll use it as a foundation to adapt Minolta 58/1.4 to EF to be able to use it on a speedbooster.
    Will let you know, how it goes!

    Cheers.

    ReplyDelete