f/1.2 side by side comparison

[dejmir]

I've managed to collect a handful of old f/1.2 lens and I plan to post here a side by side comparison of each and every one by using a CANON 6D – something which I missed from any of the internet sites.

The method: several snaps with each lens and then posting the one sharpest in the centre. Photos are processed with the Camera Raw, unsharpened or in any way corrected, unless explicitly mentioned.

Please mind that the test chart is plainly pinned to a cardboard and is by no mean perfectly plain. The yellow pin in the middle of the chart is only a centimetre away and already heavily blurred.

My intention is not to prove anything because I believe the beauty is in the eye of a beholder, however, my posts may help someone to make an informed buy. For the avoidance of doubt, I do not plan to sell any of these precious gems. It took me a while to collect them in a pristine condition. Well, not all of them, the Rokkor is without a diaphragm. Yes, I got screwed by an ebuyer, but honestly, why buying an f/1.2 and then shooting at f/8, lol. Anyway, I decided not to pass it on as the lens is otherwise perfectly in order.






Five MF @ f/1.2:
• Porst 55mm (PK),
• Porst 50mm (FX) (still to be converted to EOS mount,
• Revuenon 55mm TOMIOKA (M42),
• Revuenon 55mm (PK),
• Rokkor PF 58mm (M).

The first comparison using the Revuenons:
Older TOMIOKA first:



and 100% crop:



and 100% crop colour corrected:



and the newer Revuenon, most probably made by Cosina:



and 100% crop:

[Attila]

[kds315*]

Well, if I look at that "test Chart", my hair stands straight up. What shoudl be taken from that "test" is the target is mounted in a way, that about nothing can be said about the result?

Please redo your setup and make sure the target is really flat and the camer alooking at an 90 degree angle towards it.

Otherwise the results would be not useful and all your time and effort wasted...

[jjphoto]

[dejmir]

Thanks for the hints guys. Unfortunately, I don’t have a proper gear so set up a laboratory environment. I’m just an amateur with a 15€ tripod
I don’t want to argue, but as I vaguely remember my physic classes a measuring method if repeated in the same way with different samples can oust certain measuring deficiencies. Of course, not all deficiencies can be eliminated. Anyhow, the centre crop should be representative enough to vaguely judge the resolution, colouring and CA. If I were to compare a corner resolution, and even at the perfectly plain test chart, I would probably have to re-focus due to the narrow DOF and the field curvature.
Cheers

[dejmir]

I decided to continue posting only centre crops as the resized full frame pics do not bring any added value to the comparison.

100% crop from the Porst 55mm:



and 100% crop from the Rokkor:



and 100% crop from the Rokkor (colour corrected):




When I manage to adapt the Porst 50mm to EOS mount I'll post all corners crops comparison.

[simbon4o]

I think that the Rokkor is not focused right.

[nick_cool]

Very interesting, please keep posting!.

I would like to see samples with bokeh too if posible.

Great job!

This photo was taken with a Fujinon X 50mm f1.2 still not adapted to my D600.

[OPAL]

Most photographic lenses are developed and designed for the infinity distance! The optical qualities are going down in close distance.

I guess, making photos from test charts are really not proving the real optical qualities of glasses, but making the print firms of these test charts happy!!

[Pancolart]

[scsambrook]

Opal and Pancolart - hey, steady up there

Both cases can indeed apply, the problem is knowing which philosophy the designer(s) adopted. Whilst it's clear that 'macro' lenses were/are optimised for close ranges, the situation with fast standard lenses isn't so clear. From what I've read, German designers certainly used to compute for infinity performance - at least through to the 1960s or 70s. At the same time, Japanese designers looked for 'best' performance at ranges from around 1.5/2 meters outwards.

I guess this is one situation where empirical methodologies will triumph over theoretical debate. i.e. taking photos will give the answer

[DR.JUAN]

[Arkku]

By the way, the Rokkor looks severely yellowed; I would suggest UV treatment.

[Phenix jc]

[randreev]

[randreev]

Here is something I did couple of days ago, it is laser printed on four pages by a very old machine with again a very old toner, so print quality 2 out of 10. And yet it clearly shows where the depth of field lays, how it develops with the exception of the interesting Moire pattern in the one/third zones up and down focus. And a portion of the image is absolutely sure to be in focus.
This pattern is not the ideal one and I will be working on improvements, but conceptually it is in the wight direction, right?


Shot with Minolta 1,7/50, apparently I deleted the Rokkor 1.4 one.

[SonicScot]

So depth of field is wider at the sides than in the middle of the image? Well, you learn something every day! (or at least I do)

[randreev]

[SonicScot]

[drjs]

Nice comparison! You should consider getting a Canon FD/FL 1.2. They can be modified to EF with a $150 kit.

[dejmir]

Finally, I managed to adapt the Porst 50mm f/1.2 in Fujica mount to EOS. It will not hit the mirror on my 6D at 30m. I may still shave off some more material to reach the infinity focus – not that I really need that at f/1.2


And now to the promise I made a while ago; I post here the comparison of the centre&corner crops. As I’d suspected I had to slightly refocus when moving from the centre to the corner. Again, I'll refrain from judging the lens performance as the pictures are self-explanatory. The working method is the same as before. However, now the test chart is "perfectly flat".


Centre crops:




Bottom left corner:




Upper left corner:




Upper right corner:




Bottom right corner:




Hope you enjoy the pics

[dejmir]

[rafa1981]

Hello.

Regarding the porst 50 f1.2 conversion.

When doing conversions it's better to do the coarse job in a mechanical way (removing material), but lenses have an extra margin using the infinity adjustment that can be very handy when doing conversions to avoid to mess with the mechanical.

In the Porst 50 case there is no need to removing material at all, it's just to attach a mount (M42-EOS or rollei (thinner) adapter), sand the plastic aperture ring and adjust the infinity setting.

If there would be the possibility to get another aperture ring or to use the aperture ring of another fujica-x lens, the Porst 50 conversion would be fully reversible.

[OPAL]

The majority of photo lenses are developed to achieve the best optical results at the "infinity" distance. Tests with any test charts in a closer distance cannot result in the best image quality, so they are to my opinion useless!

A double page of the New York Times newspaper is much cheaper as any special test chart!

[Pancolart]