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10-23-2008, 02:09 AM   #16
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I will admit that I'd long considered purchasing one of these 'mystery' 1.2 lenses, but always withheld given my penchant for overall performance. The Nokton made me a changed man. Once I accepted softness (due to razor thin DoF) as an ally of bokeh, I re-opened the doors to these 1.2s.

The current ferver here has prompted me into action, so firstly thanks all for taking the plunge and sharing your thoughts.

I started to research the various versions and noted there seems to be a split in the 55mm's. There are the 8-blade Porst (Color Reflex) and Revuenon, and the 9-blade Cosina (Cosinon). There is also a 9-blade Ricoh Rikenon which I'm not sure is directly related to the others, all reportedly handled through Cosina. Since there seems to be some difference between them, I didn't immediately fall back on availability to determine which I'd add to the stable. I just went to work sifting through as many bokeh shots as I could find.

I've concluded that the Porst has a character that showed across different users similarly which was to my liking. This was all just based on available imagery, but I'm sure I noted a trend. I'd like to partly blame Abazz for a few of his shots on MFlenses that leaned me this way.

As a result, I dug up a used (but in great shape) Porst. At the current pricing, I was tempted to settle on both it and the Cosinon.

I wonder if I might ask some of you to point your new found Cosinons into some sparkly sunlit foliage and detune the focus to smudge. I'm very curious to determine just how similar/different these variants turn out to be in the bokeh dept.

10-23-2008, 04:38 AM   #17
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Feel free, Mis - I see that someone (US, I recall) just grabbed the latest (last ?) 1.2 on eBay for $250...........
10-23-2008, 05:30 AM   #18
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I like that John. I'll have to remember that.
Pirate I'll try to do that for you today. But I think the well ha dried up for now. The seller was relisiting right away with these and there's none there today.

If you like PM me your Gmail address (for big files) and I can send you a couple of RAW images. from the K20D.
10-23-2008, 06:01 AM   #19
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Here's a few OOF test shots with the Cosina. The first 4 were shot slightly OOF intentionally. Not hard to do when the lens is wide open!
These are at f1.2 (and this pushes the shutter speeds to the max in bright sun to get the proper exposure)
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The next 2 are at f4
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Here's a nearby picket fence shot wide open. It gives a good indication of the bokeh as the pickets all blend into one. The in focus picket was about 3 feet from the camera. The DOF is about 3 cms at this distance. In focus is about 1 CM when you pixel peep the shot. Razor thin!
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Btw, No sharpening or anything else. These are resized Jpegs straight from the K20D

10-23-2008, 07:46 AM   #20
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Pirate, some info on these 55mm f/1.2s.

The lens company Tomioka, of Japan, originally designed the 55mm f/1.2 lens for Yashica (whose line of lenses were called Yashinon) in M42 mount. They later went on to produce it for Cosina (Cosinon), Revue (Revuenon), Chinar (Chinon, do you see a trend here?) and with Tomioka's own brand name...wait for it...Tominon. Apparently they also built them for Vivitar (serial # begining with 84), but the only one I've ever seen is on eBay right now. As far as I know, it was never produced in P/KA mount for Pentax, just P/K, but Tomioka did build a 'P' version for Ricoh (Rikenon). I believe Tomioka transitioned off the M42 mount to bayonet mounts in 1974.

The Tomioka 55mm f/1.2 has the following specs:

Focal length: 55mm
Filter size: 58mm
Diaphragm blades: 9
Aperture range: f/1.2 to f/16
Optical formula: 7 elements in 6 groups
Closest focus: 60cm

The Porst Color Reflex 55mm f/1.2 is a different lens, and was (bizarrely) manufactured by Cosina. On some lenses it is branded simply as "Color Reflex". This lens has the following specs:

Focal length: 55mm
Filter size: 55mm
Diaphragm blades: 8
Aperture range: f/1.2 to f/22
Optical formula: 6 elements in 4 groups
Closest focus: 60cm


I read on many forums people saying the Porst is the same as the Tomioka clones, but it's not! It is also reputedly softer at larger apertures than the Tomioka. I can attest to the Cosina being sharp wide open, with none of the dreaminess exhibited by the Porst. Of course, if you actually like this dreaminess, what I call The Milk Effect, then you'll prefer the Porst.

As for Bokeh, have you seen my pub pics? I think the bokeh is great. Bright highlights look very smooth and pleasant, and the focus-to-out-of-focus transition is like warm butter, as Peter demonstrated with his fence shot. But bokeh is about personal taste, and these vary

Cheers,


--M.

Last edited by Miserere; 10-29-2008 at 04:26 PM.
10-23-2008, 10:19 AM   #21
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Peter and Misere - very kind of you to share such detailed info so quickly, many thanks to you both.

One thing about observing a lens strictly for its bokeh is that even small images suffice to show its character - I won't need to trouble you for the larger images Peter, though if you feel compelled, I'd welcome as many as you care to shoot here. I love these sort of threads, its the way I shop!

It makes me happy to note my hunch was correct regarding the Porst. I did look at a lot of shots and felt there was something different afoot with that one and passed up a chance at the Cosinon to grab it. Had it been the same, I'd have missed a NIB lens for a used one at the same price for nothing.

Well, again, I'm thankful for your time gents and look forward to your posts here. I hope a few shots of the Porst for comparison might be of interest to you?

Regards,


Kelly.
10-23-2008, 11:43 AM   #22
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just got mine in the mail.. cant wait till i come home

i will note however, the 58mm filter ring means the neat little lens hood from the takumar 85 1.8/9 and the 135 f2.5 will fit right into place.

and another thing that kind of bugs me is that there is no stop between 1.2 and 2.0! thats 1.4 and 1.8 that could have snuck in there.

now i'm thinking of dis assembling the ring and filing in an extra notch so that i can have an inbetween stop.
10-23-2008, 12:23 PM   #23
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Most of my info agrees with Mis, but here are some conflicting nuggets I have gathered. Maybe the following can be authoritatively denied/confirmed?

1. The Porst has 6 diaphragm blades.

2. There was also an "Auto Sears" made by Tomioka.

BTW an Auto Yashinon (M42 mount) is available in eBay auction 310092017692.

10-23-2008, 12:30 PM   #24
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QuoteOriginally posted by rparmar Quote
1. The Porst has 6 diaphragm blades.
1.2 + 6 = ferrari w/ diesel, can't be true
10-23-2008, 12:50 PM   #25
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I realise the over the top processing on these may not show off the lens at its best, but the shots do illustrate that the Cosina works for me artistically. The first was f/4 IIRC and the second f/2. The sticker was on a pole, the curvature of which is evident in the blur to the right.

This Way (Orange)




Sticker

10-23-2008, 01:44 PM   #26
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QuoteOriginally posted by thePiRaTE!! Quote
Well, again, I'm thankful for your time gents and look forward to your posts here. I hope a few shots of the Porst for comparison might be of interest to you?
Kelly,

You're most welcome. I also thought it would be good to have a place on the Net with this info together. Hopefully Google will lead people to that post and it will clear the murky f/1.2 waters.

So you did buy the Porst? I would definitely like to see some examples from you, I'm sure you'll know how to wield it to it's highest potential

The Porst is probably fantastic for portraits, especially with the crop factor on APS-C. I wanted a low-light lens for pubs and concerts, so the Cosina made more sense to me. I hope to go to a concert tonight (in a pub!) so I'll be able to see how it fares. I'll be sure to post any examples.
10-23-2008, 01:46 PM   #27
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QuoteOriginally posted by Gooshin Quote
now i'm thinking of dis assembling the ring and filing in an extra notch so that i can have an inbetween stop.
I think about that every day...
10-23-2008, 01:48 PM   #28
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QuoteOriginally posted by rparmar Quote
I realise the over the top processing on these may not show off the lens at its best, but the shots do illustrate that the Cosina works for me artistically.
Dude, for me too; I love those shots. They look like something I would like to have photographed.

I think you might be my long-lost Irish brother from another photographer mother
10-23-2008, 02:02 PM   #29
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QuoteOriginally posted by rparmar Quote
Most of my info agrees with Mis, but here are some conflicting nuggets I have gathered. Maybe the following can be authoritatively denied/confirmed?

1. The Porst has 6 diaphragm blades.
This is like the Porst, and although it's a bit difficult to see, there are 8 aperture blades. And I think this guy pulled the optical formula out of his arse or copied it from the Tomioka. Either way, it's incorrect.

QuoteQuote:
2. There was also an "Auto Sears" made by Tomioka.
No idea. Could be.[/QUOTE]
10-23-2008, 04:26 PM   #30
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QuoteOriginally posted by Miserere Quote
Kelly,

You're most welcome. I also thought it would be good to have a place on the Net with this info together. Hopefully Google will lead people to that post and it will clear the murky f/1.2 waters.
Maybe It would be worthwhile to update the title of this thread for easier ID in search? Or if you cared to start a definitive 55/f1.2 'LBA' thread. One for the ages - at the price, I'm sure it will see a massive population growth over time.

QuoteOriginally posted by Miserere:
So you did buy the Porst? I would definitely like to see some examples from you, I'm sure you'll know how to wield it to it's highest potential

The Porst is probably fantastic for portraits, especially with the crop factor on APS-C. I wanted a low-light lens for pubs and concerts, so the Cosina made more sense to me. I hope to go to a concert tonight (in a pub!) so I'll be able to see how it fares. I'll be sure to post any examples.
I did yes, though I don't yet have it - and thanks for the vote of confidence. I'll certainly try to expose what character I can of its oof powers.

Looking forward to your pics, I may end up with both variants some day, heh.


K.
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