[Deimos]

The cosina, revuenon, yashinon etc are all the same optics (I think the revuenon has a nicer body than the cosina with the metal focus ring), these are also the same as the (expensive) M42 Tomioka variants except for the cut rear element. the porst is a different design with a dreamier and less sharp/contrasty look. I think the Pentax 1.2s are a tiny bit sharper but I dont like the bokeh as much

OK, I was 4 days away (payday!) from buying my first F1.2 lens (a Cosina 55mm) when another option popped up - a Pentax K 50mm F1:2.

https://www.pentaxforums.com/userreviews/cosina-55mm-f1-2.html#review2179

Mikes 1st photo is the whole reason Im buying a F1.2 lens, it will never get stopped down and is being bought purely for the bokeh effect so I can experiment and learn at the same time.
Im leaning towards the Cosina as that was the lens used in the photo I love so much, so don't really know that much about the Pentax K one?
Is there any reason why I should go for the Pentax over the Cosina or should I just follow my hearts desire and get the Cosina - for what Im planning the 5mm difference in focal length doesn't bother me in the slightest, this as all about wide open for me.
I know about the Porst, Yashinon and Revuenon versions, but they are Plan B
LBA might be expensive, but damn it is fun, I have a long list of possible shots I want to try out, I have even written them down and this is before I have even bought the lens!

[disco_owner]

My Copy of Revuenon 55 F1.2 had Probs since it landed on my lap , the Aperture Blades Would not stop down Quick enough and it was constantly over exposing shots by a long Mile

after a Visit to my Local camera repairer a service and glass clean the lens is back to it's Old Glory days , aperture blades stopping down beautifully without any delay.

here is an Example of a shot I took this morning at Local Flower Nursery.

[Deimos]

Sorry to hear that, I guess I pretty much only shot it wide open and never noticed. Great shot!

[disco_owner]

Sorry to hear that, I guess I pretty much only shot it wide open and never noticed. Great shot!

Thanks phill , That's where I noticed it was the worst = Wide open images had bright spots all over after shooting with this lens , then I figured out it was the aperture behaviour ,it's all good now.been for a service and a Glass Clean. it's really spotless.

[jaywes]

Extremely excited to have just purchased a Pentax A 50mm 1.2! Got it for a steal too.. Awaiting delivery now! Can't wait!!

[Achromatter]

Did you get the one on ebay, with the nick in the rear element, for ~$350?

[jaywes]

;-) you are right dear sir! Had to get it.. Too much of a deal!

[jaywes]

..arrived in impeccable shape! Like new! Test shots look great. Not sure where the nic is tho. Not visible with the naked eye for sure. A steal by any means

[snake]

Now this thread has me looking at Porst and Revunon 55 1.2s, since those are typically available on my market. Decisions... As I understand it, the two don't vary too much from one another n how they render. Is that accurate? Which one is accepted to be the sharper one from wider apertures?

[steve1307]

Now this thread has me looking at Porst and Revunon 55 1.2s, since those are typically available on my market. Decisions... As I understand it, the two don't vary too much from one another n how they render. Is that accurate? Which one is accepted to be the sharper one from wider apertures?

Similar... but definitely not the same The lenses have different construction.
I compared many shots from the 2 on the forum here before buying the Revuenon.
The Porst appears to be less sharp (in relative terms) wide open, but at f1.2 the dof is so thin it is difficult to nail the focus where you want it with any lens.

Have a look at some samples (searching the this f1.2 thread and also the "Cosina 55mm f1.2 club" which has examples of both)


Revuenon 55mm F1.2 MC Lens Reviews - Miscellaneous Lenses - Pentax Lens Review Database

Porst 55mm F1.2 Color Reflex MC Auto Lens Reviews - Miscellaneous Lenses - Pentax Lens Review Database

1 user "Pepe Guitarra" has owned and reviewed both lenses here.


Some more samples of the Revuenon
https://www.pentaxforums.com/forums/lens-sample-photo-archive/153873-revuenon-55mm-f1-2-a.html


I would expect you could find the Porst for much cheaper than the Revuenon/Cosina/Tomioka version, and the Revuenon/Cosina for cheaper than a Pentax K 50mm f1.2.

[Achromatter]

..arrived in impeccable shape! Like new! Test shots look great. Not sure where the nic is tho. Not visible with the naked eye for sure. A steal by any means

That was a good deal. My max bid was a bit lower than your purchase price, as I already have two of these, I figured why drive up the price on a potentially flawed lens.

Any way, start shooting with it if you have time. Maybe one day we could meet up and compare toys?

[jaywes]

That was a good deal. My max bid was a bit lower than your purchase price, as I already have two of these, I figured why drive up the price on a potentially flawed lens.

Any way, start shooting with it if you have time. Maybe one day we could meet up and compare toys?

I too had that in the back of my head about the nic on the rear element but I figured it was small judging from the picture. Having it in hand you can't see what the previous person was referring to. It really is in excellent condition.

I do not have one so I am glad to have been able to get it for that cheaply. I have a M50 1.4 but the metering gets tedious at times and I can't shoot my child(ren) with it much. This A lens is a world of a difference. Smooth and simple. This was another reason. Easier use over using green button. That would be fun in the future to get fellow NY pentexians together in the city and shoot!

[Kerrowdown]

Awaiting delivery now! Can't wait!!

Enjoy it once you get it.

[jaywes]

Took a few while eating lunch in my car.. Will have to get some practice with the shallow DOF. Trickier than I thought but then again I only had my k-r not k-5.

[narual]

Just got my Porst 55mm ƒ1.2 yesterday and took it out today to photograph an arts fair. Holy *hell* people weren't kidding about it being hard to focus (and about it putting odd halos around people in bright light). I sanded off the paint so the K5 would think it was an A lens and meter better, but didn't do the best job so it kept jumping back and forth between thinking it was an A and thinking it was an M.

A few samples:


Photo_taken_on_2013-08-17_at_162937_-_using_a__PENTAX_PENTAX_K-5__with_a_A_Series_Lens_at_55_mm-1-4000_sec_at_f_-_1.2-ISO_80_-_.jpg


Photo_taken_on_2013-08-17_at_171856_-_using_a__PENTAX_PENTAX_K-5__with_a_A_Series_Lens_at_55_mm-1-3200_sec_at_f_-_1.2-ISO_80_-_.jpg


Photo_taken_on_2013-08-17_at_194314_-_using_a__PENTAX_PENTAX_K-5__with_a_A_Series_Lens_at_55_mm-1-125_sec_at_f_-_1.2-ISO_80_-_.jpg


Photo_taken_on_2013-08-17_at_193048_-_using_a__PENTAX_PENTAX_K-5__with_a_A_Series_Lens_at_55_mm-1-125_sec_at_f_-_1.2-ISO_80_-_.jpg


Photo_taken_on_2013-08-17_at_193620_-_using_a___PENTAX_K-5__with_a_A_Series_Lens_at_55_mm-1-8000_sec_at_f_-_1.2-ISO_80_-_.jpg (this one's fairly processed, so maybe not a great example, but I liked the way it came out)


Photo_taken_on_2013-08-17_at_192822_-_using_a__PENTAX_PENTAX_K-5__with_a_A_Series_Lens_at_55_mm-1-1600_sec_at_f_-_1.2-ISO_200_-_.jpg