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7 fast 55mm and 50mm quick OOF rendering comparison
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PostPosted: Tue Oct 05, 2010 8:17 pm    Post subject: 7 fast 55mm and 50mm quick OOF rendering comparison Reply with quote

I wanted to check, if there are some differences between Tomioka designed lenses produced by/for different brands. I own few of them, so I did quick comparison of they OOF lights rendering, which I find the quickest and easiest way to see some differences.

The contenders:


Porst Color Reflex MC Auto 1.4/55 (SN: 101690) - purple coating
Ricoh Auto Rikenon 1.4/55 - honey coating like Tomika
Auto Revuenon 1.4/55 - honey violet coating
Porst Color Reflex MC Auto 1.4/55 (SN: 109479) - blue violet coating

Auto Revuenon Tomioka 1.2/55 - honey coating - this one has cracked rear element, which can be seen in bokeh up to f2.8....but hey, don't buy it for 20€ Cool, just for comparison to my Porst 1.2/55
Porst Color Reflex MC 1.2/55 (P/K) - green, yellow, violet coating
Pentax-M 1.4/50 - I wanted to show some "brand" lens, unfortunately I have not my Pentax FA 1.4/50 by me.

Coating colors:


I didn't compared sharpness, because at this distance I will compare my ability to get focus right... anyway the sharpness looks at fully opened aperture roughly the same for all lenses... except Pentax, which looks slightly sharper. But this can be due to deeper DOF at 50mm. On the other side, the 1.2 lenses looks slightly softer, again, probably due to shallower DOF.

White balance is fixed, bud I leaved the camera to meter for every lens automatically. Only the Porst 1.2 showed constantly some advantage fully open. The Tomioka metered fully open slightly slower than some 1.4 lenses, it can be due to the cracked element. Still the picture at f1.2 is brighter than f1.4, which metered the same on this lens. I will explore the exposure difference surely more latter.

Now the pictures. EXIF is intact, but you can get all info from file name.

@f1.2
Porst 1.2/55

Tomioka 1.2/55


@f1.4
Pentax 1.4/50

Porst 1.4/55 SN: 1690

Porst 1.4/55 NS: 9479

Revuenon 1.4/55

Rikenon 1.4/55

Porst 1.2/55 - can't be set to 1.4
Tomioka 1.2/55


@f2.0
Pentax 1.4/50

Porst 1.4/55 SN: 1690

Porst 1.4/55 NS: 9479

Revuenon 1.4/55

Rikenon 1.4/55

Porst 1.2/55

Tomioka 1.2/55


@f2.8
Pentax 1.4/50

Porst 1.4/55 SN: 1690

Porst 1.4/55 NS: 9479

Revuenon 1.4/55

Rikenon 1.4/55

Porst 1.2/55

Tomioka 1.2/55


Today's conclusions:
- all lenses are probably based on same optical scheme 7 elements in 6 groups as expected, the OOF rendering differences are really minor.
- group of Porsts 1.4/55 and Rikenon 1.4/55 are the same, probably original Tomioka 1.4/55.
- Revuenon 1.4/55 is probably somehow redesigned. According to my previous comparisons, slightly softer. Maybe some cost oriented optimizations. I had one with same lettering on front ring but different rubber ring and it showed the same behavior.

Older Revuenons with different lettering are probably same design as Porst and Rikenon.

- 1.2 lenses are without doubt true 1.2 designs, the DOF is narrower and Porst shows some advantage in exposure times wide open.
- Porst 1.2 looks slightly different to Tomioka. But Tomioka has non-symmetrical rear element, which can cause differences in OOF lights rendering.
- 1.2 lenses are have slightly longer focal length than 1.4.

Sometimes latter I will explore more differences between both 1.2 lenses (OOF rendering, sharpness, contrast and exposure). And between Porst 1.4/55 MC and Revuenon 1.4/55 (probably only sharpness comparison). Other lenses will be sold. As only differences I will probably discover will be color rendering due to different coatings.

Thank you for viewing.


Last edited by BRunner on Wed Oct 06, 2010 6:04 am; edited 1 time in total


PostPosted: Tue Oct 05, 2010 8:30 pm    Post subject: Reply with quote

Reserved for next comparisons...


PostPosted: Tue Oct 05, 2010 8:31 pm    Post subject: Reply with quote

Reserved for next comparisons...


PostPosted: Tue Oct 05, 2010 8:35 pm    Post subject: Reply with quote

Superb test ! Cant wait for the 1.2 sharpness test.

But based on this, my vote goes for the Pentax 1.4.


PostPosted: Tue Oct 05, 2010 9:18 pm    Post subject: Reply with quote

It looks to me like the Revuenon is focused slightly more to the front, e.g. look at the paw of the dog.


PostPosted: Tue Oct 05, 2010 9:24 pm    Post subject: Reply with quote

At wide open there are amazing differences in the COC shape, meaning different types and degrees of aberrations, would seem difficult to believe they are the same lens with a different name. On top of that the Pentax seems to be less corrected and therefore have a smoother bokeh.
Given that they are the same lens, the differences must be due to the build tolerances in the construction of the lens elements, which tells a lot about the importance of a consistent quality control for repeatable results.


PostPosted: Wed Oct 06, 2010 12:31 am    Post subject: Reply with quote

Mind-numbing doggie repetition, but very informative nonetheless. Thank you.


PostPosted: Wed Oct 06, 2010 4:51 am    Post subject: Reply with quote

Orio wrote:
On top of that the Pentax seems to be less corrected and therefore have a smoother bokeh.


Yes, I noticed that, too - liked Pentax shots the most. I wonder how would SMC Takumar 50/1.4 fare.


PostPosted: Wed Oct 06, 2010 6:37 am    Post subject: Reply with quote

Arkku wrote:
It looks to me like the Revuenon is focused slightly more to the front, e.g. look at the paw of the dog.

Yes, unfortunately it's not easy to nail focus correctly at this distance and f1.2-1.4. Even with LiveView. Where is the APS-C super-deep DOF? Wink
I will compare sharpness latter with more suitable scene for focusing.

aoleg wrote:
Yes, I noticed that, too - liked Pentax shots the most. I wonder how would SMC Takumar 50/1.4 fare.

Unfortunately I don't own Tak, only Pentax-M and FA 1.4/50. But I hope, I can borrow one sometime later and do some comparison between these three.


PostPosted: Wed Oct 06, 2010 7:45 am    Post subject: Reply with quote

Orio wrote:
...would seem difficult to believe they are the same lens with a different name...

I don't get, what exactly you mean. If you mean the same optical scheme (7/6) for all lenses, then this comparison shows us, how important is the fine-tuning of basic design and why we buy Zeiss, Leica or maybe Pentax Wink quality.


PostPosted: Wed Oct 06, 2010 8:42 am    Post subject: Reply with quote

By-the-way, does anyone have a brochure or other “official” source displaying the optical diagram of any of the “Tomioka” 55mm f/1.4 lenses?


PostPosted: Wed Oct 06, 2010 9:02 am    Post subject: Reply with quote

Nice test. I suggest putting your object skewed not enface when testing. Grid-like one would be best. I mean then you could find most sharp part for comparison. Cut it out and post it full size. Hopefully outer light and fixed WB on camera. Enough said Smile. Oh yes, i envy your Tomioka sample Smile!

Last edited by Pancolart on Wed Oct 06, 2010 9:47 am; edited 1 time in total


PostPosted: Wed Oct 06, 2010 9:31 am    Post subject: Reply with quote

Great!
Thank you very much for doing this test!

The difference between f1.2 and f1.4 is quite strong.
I wouldn't have thought it to be that much.

So, it is worth to have an f1.2 lens! Wink


PostPosted: Wed Oct 06, 2010 11:20 am    Post subject: Reply with quote

Arkku wrote:
By-the-way, does anyone have a brochure or other “official” source displaying the optical diagram of any of the “Tomioka” 55mm f/1.4 lenses?


Maybe this will help?


Klaus


PostPosted: Wed Oct 06, 2010 11:23 am    Post subject: Reply with quote

exaklaus wrote:
Maybe this will help?


Is there reason to believe that the 50mm f/1.4 Yashinon has the same formula as the 55mm f/1.4 lenses?


PostPosted: Wed Oct 06, 2010 11:28 am    Post subject: Reply with quote

Ups, was to fast, only had that 55/1,2 in mind.
Forget about...
Klaus