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11-11-2008, 12:22 PM   #16
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QuoteOriginally posted by thePiRaTE!! Quote
edit 2 - Is the newer Cosina/Tomioka 1.2 you have consistant with this focus range?
i will comment once i get home.

11-11-2008, 12:38 PM   #17
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QuoteOriginally posted by Gooshin Quote
i will comment once i get home.
Focus throw/range etc. . .could you explain what this means exactly?
11-11-2008, 12:44 PM   #18
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QuoteOriginally posted by konraDarnok Quote
Focus throw/range etc. . .could you explain what this means exactly?
focus throw is how much your focus ring rotates from min distance to infinity.


45 degrees or less (1/4 turn) is considered very short, 200+ is considered very long.


Longer focus throws help with manual focusing, since the viewfinder isnt as large and bright as we would like it to be, by having a very long focus throw you can find the perfect focus more easily

fast focus throws make it very easy to "miss" it, and unless its bright outside, and you have very good vision and finger dexterity, chances are you will be slightly frustrated.


however, fast/short focus throws make auto-focusing faster, which is often the double edged sword with some lenses that are boasted as being "fast autofocus", when its partly due to the fact that their focus throws are so short, that any attempt at manual focusing will yield in frustration.
11-11-2008, 02:11 PM   #19
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QuoteOriginally posted by Miserere Quote
Thanks for that write up, Kelly. Very thoughtful and happily lacking in MTF charts
Thanks Mis! I thought about adding the pics, but in the end it was less work to just describe it. I may post some specific bokeh tests though, as thats the real draw for me to these guys.

QuoteOriginally posted by Miserere Quote
If by backwards, you mean "the Canon way", then the new Cosinas (and the old ones too) also focus backwards. It's one of those things that annoy me about many old lenses. As a side note, many of the old Tokinas were built so they focused and zoomed in the same direction as the camera they had the mount for, instead of using the one-direction-is-fine-for-all approach of other 3rd party brands. Props to Tokina.
After using the Yashinon more this morning I realised its the same as the Porst so these 1.2s seems consistant in this way. Interestingly, all the Cosina produced Voigts, the Zeiss, Pentax and the Super Tak I have are all the same way. These being the sum of my experience in photography, I assumed it was a standard, interesting to learn its not.

QuoteOriginally posted by Miserere Quote
I don't have the Cosina with me, but I think it travels at least 1/2 a turn, maybe even close to 3/4. Are you sure you got 110 degrees right? I have the Pentax-A 50mm f/1.4 with me here and it turns about 220 degrees.
You are right, I had the degress halved. You'll need to double my numbers, in fact, the 55s turn closer to 3/4 of a turn now that I'm measuring. I'll go back and edit my post.

K.

11-11-2008, 06:15 PM   #20
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The focus throw of the new Cosina 55mm f/1.2 is exactly 180 degrees.
11-11-2008, 06:30 PM   #21
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QuoteOriginally posted by Miserere Quote
The focus throw of the new Cosina 55mm f/1.2 is exactly 180 degrees.
Seems over time a lot of things have changed between these releases. Wonder if it would be worthwhile to compile this info?

Anyways, I thought I'd share a couple of Porst samples from a trip to the zoo on the weekend. Got some decent low light performance out of it.

Porst @ 1.2, ISO 200, 1/20.


Porst @ 1.2, ISO 400, 1/60


...and another for the bokeh people

Porst @ 1.2


K.
11-11-2008, 10:02 PM   #22
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I like the monkey, although the bokeh is cool...even though I'm not one of the "bokeh people"...
11-11-2008, 10:13 PM   #23
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I like the monkey shot too, very sharp and I see the eyes and hair clearly. That is called Cotton Top Tamarin, I shot a similar monkey in a zoo visit last week too. That type of monkey has the strangest voice when they communicate with each other, the cutest sound that I have heard from a monkey, sounds more like a bird.

Mis, shame on me in not having more than 2 test shots. I have way more lens that I can trade, sell or test. Here is one test picture that I was delighted to shoot in iso 200. Had I used the other 50mm, I would have to use ISO 400.


I used the Cosina 55mm f/1.2 with my K10D and took a picture of Pentax F 35-135mm. I have to say that I am liking the soft bokeh. It is quite sharp. So far, the caveats that I find is the turning in MF. I find a gap in turning from left getting to the focus spot and that spot from right seems to yield a gap. This happens with other glass too but I find it quite big in the Cosina that I have to be more careful not to hit it the first time I get focus confirmation. It is as if I have to wait for the focus lock to confirm itself for a second before I can hit the shutter. I don't know if I make any sense but I do find a thing to get you all confused in my whining about.

But I can't wait to go out night shooting into traffic lights, pub signs, restaurants highlights with neons.

Thanks,
Hin


Last edited by hinman; 11-12-2008 at 07:18 AM.
11-12-2008, 06:14 AM   #24
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Hin, I'm afraid I don't understand what you're refering to when you talk about "the gap". I've found the K10D's focus confirmation is too optimistic with this lens and is pretty much useless; I rely 100% on my eyes (and my luck) when I use it.

And yes, shame on you for only having taken 2 test shots
11-12-2008, 08:55 AM   #25
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You know, I can speak to this issue of focus confirmation. During my little shoot-out, I was having a heck of a time hitting my intended focus. I've already set my diopter several times in the past, but working with 1.2 and minimum focus distance leaves zero room for error.

I found focus confirmation came on about the time I saw things come into focus, but what I was seeing and what the indicator were telling me were premature, I always tended to focus just in front of my intended plane. Further to this, I noted the indicator would stay on during micro adjusting which means its really only a rough guide at best. I adjusted my diopter 1 tick inside fully right and it improved my visual perception of focus.

Right now - at least with my 20/20 eyes at mfd - I ever so slightly focus just further past my perception of perfect focus and it shoots perfect. This seemed to work out for all the lenses I was shooting for this test.

Again though, the DoF at 1.2 certainly brings the issues of slight focus imperfections to a frustrating fore, but I now have a system that seems to work, for me.

edit - and thanks for the ID on the Tamarin Hin, I've updated my 'folio page.

Last edited by thePiRaTE!!; 11-12-2008 at 09:02 AM.
11-12-2008, 11:46 AM   #26
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QuoteOriginally posted by thePiRaTE!! Quote
You know, I can speak to this issue of focus confirmation. During my little shoot-out, I was having a heck of a time hitting my intended focus. I've already set my diopter several times in the past, but working with 1.2 and minimum focus distance leaves zero room for error.

I found focus confirmation came on about the time I saw things come into focus, but what I was seeing and what the indicator were telling me were premature, I always tended to focus just in front of my intended plane. Further to this, I noted the indicator would stay on during micro adjusting which means its really only a rough guide at best. I adjusted my diopter 1 tick inside fully right and it improved my visual perception of focus.

Right now - at least with my 20/20 eyes at mfd - I ever so slightly focus just further past my perception of perfect focus and it shoots perfect. This seemed to work out for all the lenses I was shooting for this test.

Again though, the DoF at 1.2 certainly brings the issues of slight focus imperfections to a frustrating fore, but I now have a system that seems to work, for me.

edit - and thanks for the ID on the Tamarin Hin, I've updated my 'folio page.
This is the exactly the problem that I ran into. Perhaps not because of the Cosina per se but a thing to watch out in narrow DOF f/1.2 combined with the latency in AF confirmation from our slower AF system in Pentax.

I feel as if the AF confirmation has a range to stay confirmed making you wonder, should I go from left or should I go from right. I don't have a 20/20 vision and I wear prescription glass. I use the default focusing screen. Perhaps, it is time for me to revisit the need and techniques along with the valuable insights that I gather here and that in dslr discussion on how to manual focus.

Hin
12-20-2008, 06:54 AM   #27
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Agree, it does make it a little more challenging with such shallow dof, almost considering getting split screen after holidays

It's been raining for a week now, so to bring up some color (Christmas tree in the bg):



Regards,
D
12-20-2008, 08:30 AM   #28
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D.V., that is a frickin awesome shot. Beautiful!

Wow...seriously. Great use of this lens, yessir
12-20-2008, 09:21 AM   #29
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QuoteOriginally posted by Duh_Vinci Quote
Agree, it does make it a little more challenging with such shallow dof, almost considering getting split screen after holidays

It's been raining for a week now, so to bring up some color (Christmas tree in the bg):



Regards,
D
12-20-2008, 10:11 AM   #30
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D & Kelly, great shots.

(*&(*^*(&^% LBA.


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