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06-16-2010, 06:42 AM   #346
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that is an interesting comparison AXL, In that comparison the SMCP 50mm f/1.2 is the clear winner on account of it's smooth bokeh rendering. The Carl zeiss 50mm f/1.4 planar is even worse than the DA*55in it's rendering of OOF highlights: it tends to be very harsh - The K 50 f/1.2 is the complete opposite.


something else I noticed is that the SMCP 50mm f/1.2 has less PF than the DA*55 at the widest aperture settings,curious.

06-16-2010, 07:02 AM   #347
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True indeed.
The PF at wide open is all over the place with the DA*. Even in the middle of the frame.. On the other side Cas are prretty well corrected with DA*. My K50 shows pretty heavy red/green CA which are nearly non existent with DA* but as I said and you concured the "old lady" beats the hell out of DA* when it comes to OOF.
It's shame as I really wanted to like the DA* but I can't afford to spend this kind of money when I own lens 30 yeears older & half the price that is better in the one respect that fast lenses are intended for...
06-16-2010, 07:03 AM   #348
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QuoteOriginally posted by axl Quote
OK, it looks like you guys will have to bear with me for bit longer!
Decided to keep the K50/1.2 and take the DA*55 back to shop...
will post shoot out results soon!

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06-16-2010, 07:11 AM   #349
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QuoteOriginally posted by Digitalis Quote
that is an interesting comparison AXL, In that comparison the SMCP 50mm f/1.2 is the clear winner on account of it's smooth bokeh rendering. The Carl zeiss 50mm f/1.4 planar is even worse than the DA*55in it's rendering of OOF highlights: it tends to be very harsh - The K 50 f/1.2 is the complete opposite.


something else I noticed is that the SMCP 50mm f/1.2 has less PF than the DA*55 at the widest aperture settings,curious.
Give the k and A f1.2 lenses have the 7/6 design and the DA* 55 have a completely new 9/8 design, it also makes it tough to see what the Aero Bright coating does. This coating is a bigger mystery than the Ghostless Coating but Aero Bright is supposed to increase transmission while reducing ghosting and flare. I wonder if it is for improved low light gathering.

Axl, I wonder if there is a way to compare the K f1.2 and it wide open in the same conditions and see if they pick close to the same shutter speed. Are the elements in the DA* also as big as the k?

Edit: Since Pentax is building the A 50mm f1.2 again, I wonder what would happen if the used Aero Bright on some of those.

06-16-2010, 08:07 AM   #350
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Blue, you may be on to something there!
But I don't know if I'll be able to check... I'm on my way to shop to reeturn DA*
I have some shots from 1st day at PC at home I'll chek those later!
06-16-2010, 09:19 AM   #351
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"Give the k and A f1.2 lenses have the 7/6 design and the DA* 55 have a completely new 9/8 design, it also makes it tough to see what the Aero Bright coating does. This coating is a bigger mystery than the Ghostless Coating but Aero Bright is supposed to increase transmission while reducing ghosting and flare. I wonder if it is for improved low light gathering."

I am mystified as to what the aero bright coating does as well, your hypothesis that it increases transmission is not without merit. Though I doubt it improves transmission noticeably, bear in mind that f/1.4 and f/1.2 are a half stop apart. In My testing, comparing the transmission of lenses I have attained results from the FA 50mm f/1.4 which transmitted 93.6% equalling T=1.4.6 The SMC K 50mm f/1.2 transmitting 96.8% T=1.2.2

tests were conducted on a full frame pentax LX with T-max 100, standard development in D76 - three copies of each lens to minimise sample error, and subsequent analysis of the negatives with densitometry readings from the negatives used to calculate the absolute transmission of light recorded on film when compared to the light reading from an exposure meter.
06-16-2010, 10:42 AM   #352
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Good to hear Axl!

06-16-2010, 12:35 PM   #353
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Great thread!

Here is one shot with K-7/SMC Pentax 50mm f1.2.
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06-17-2010, 01:21 AM   #354
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Interesting. I was kind of considering the DA* myself, so very useful to see these samples.

Meanwhile the A in very poor light, where the speed makes a real difference:

06-17-2010, 01:31 AM   #355
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QuoteOriginally posted by schneider Quote
Interesting. I was kind of considering the DA* myself, so very useful to see these samples.

Meanwhile the A in very poor light, where the speed makes a real difference:
the light transmission of the 1.2 is really awesome. I had never really struggled shooting with it under very demanding situations.
06-17-2010, 03:51 AM   #356
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QuoteOriginally posted by Pentaxor Quote
the light transmission of the 1.2 is really awesome. I had never really struggled shooting with it under very demanding situations.
Me too. It's a low light beast or light sucker.
06-17-2010, 11:08 AM   #357
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QuoteOriginally posted by Digitalis Quote
"Give the k and A f1.2 lenses have the 7/6 design and the DA* 55 have a completely new 9/8 design, it also makes it tough to see what the Aero Bright coating does. This coating is a bigger mystery than the Ghostless Coating but Aero Bright is supposed to increase transmission while reducing ghosting and flare. I wonder if it is for improved low light gathering."

I am mystified as to what the aero bright coating does as well, your hypothesis that it increases transmission is not without merit. Though I doubt it improves transmission noticeably, bear in mind that f/1.4 and f/1.2 are a half stop apart. In My testing, comparing the transmission of lenses I have attained results from the FA 50mm f/1.4 which transmitted 93.6% equalling T=1.4.6 The SMC K 50mm f/1.2 transmitting 96.8% T=1.2.2

tests were conducted on a full frame pentax LX with T-max 100, standard development in D76 - three copies of each lens to minimise sample error, and subsequent analysis of the negatives with densitometry readings from the negatives used to calculate the absolute transmission of light recorded on film when compared to the light reading from an exposure meter.
Given how much the SMC coating improved light transmission, it is hard to believe that the Aero Bright increased it significantly. We will see if it shows up on any new lenses. I'm curious if it is a marketing hype. It sounds a lot like a combination to replaces SMC & Ghostless Coating.

It would be interesting to see your experiment repeated including this DA* 55mm in the test.
06-17-2010, 04:39 PM   #358
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Here is one with the Cosina 55mm f/1.2 wide open and with Raynox 150 close up filter:

06-18-2010, 03:32 AM   #359
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Love the bokeh:

06-18-2010, 04:22 AM   #360
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Anyone got a spare $3800?
Pentax LX 2000 + A 50mm f/1.2 Special Lens Kit LX2000 - eBay, 35mm SLR, Film Cameras, Cameras Photo. (end time 08-Jul-10 17:00:26 AEST)
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