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10-04-2016, 09:37 PM - 1 Like   #16
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As I commented earlier today on a 1.2 thread elsewhere -- I thought that the DSLR sensors can't actually take full advantage of faster lenses, so there is no great advantage to super-fast lenses. This could be different, however, depending on your camera/camera type.


Described here:

F-stop blues - DxOMark

https://forum.dxomark.com/index.php?topic=371.0

http://luminous-landscape.com/an-open-letter-to-the-major-camera-manufacturers/

10-04-2016, 09:47 PM   #17
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QuoteOriginally posted by leekil Quote
I thought that the DSLR sensors can't actually take full advantage of faster lenses, so there is no great advantage to super-fast lenses.
In my testing Pentax DSLRs are able to take advantage of the extra light gathering capacity of faster lenses. Unfortunately I'm on my work laptop...i'll post some data on this. DxO are full of it.
10-04-2016, 10:31 PM   #18
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QuoteOriginally posted by leekil Quote
As I commented earlier today on a 1.2 thread elsewhere -- I thought that the DSLR sensors can't actually take full advantage of faster lenses, so there is no great advantage to super-fast lenses. This could be different, however, depending on your camera/camera type.


Described here:

F-stop blues - DxOMark

https://forum.dxomark.com/index.php?topic=371.0

http://luminous-landscape.com/an-open-letter-to-the-major-camera-manufacturers/


Seems kinda bogus... I just set my k70 to manual and snapped three shots, going down 1 stop on the aperture with each one, starting at f1.4. There was an obvious decrease in light with each one that almost correlated exactly in exposure as a second set of shots where I decreased each shot 1 stop via ISO. So there's obviously a benefit to fast lenses.
10-04-2016, 10:41 PM   #19
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QuoteOriginally posted by Digitalis Quote
DxO are full of it.
You mean like this psycho-babble?

“We have been very surprised,” explained Frédéric Guichard, chief scientist at DxO Labs, “to find out that some of the gain from wider lens openings seems to be offset by the present state of sensor technology. Our measurements all point in the same direction: as you go further than f/ 4 – to f /2 and wider, the accrued quantity of light falls marginally onto the sensor. A stronger and stronger part of this additional light is blocked or lost. I am therefore inclined to question the real benefit of faster lenses.”

Ultimately, someone has to actually look at photographs in order for photography to have any meaning to real people. There are photographs that have the power to evoke an emotional response from people, what happened to produce those photographs seems somewhat disconnected from "the accrued quantity of light falls marginally onto the sensor. A stronger and stronger part of this additional light is blocked or lost."

10-04-2016, 11:30 PM   #20
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Pentax has 50mm 1.2 MF before, it was a success, they might revive that lens with AF someday, we never know AFAIK, the 85mm f1.2 from Canon is a huge success, size and price tag are downsize of these kind of lens though ^^
10-05-2016, 12:19 AM - 1 Like   #21
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QuoteOriginally posted by enyceckk Quote
Are there any Auto focus f1.2 lens for Pentax K mount?

Thanks,
What and take away the frustration of missing focus manually.
10-05-2016, 12:20 AM - 1 Like   #22
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QuoteOriginally posted by RGlasel Quote
You mean like this psycho-babble?

“We have been very surprised,” explained Frédéric Guichard, chief scientist at DxO Labs, “to find out that some of the gain from wider lens openings seems to be offset by the present state of sensor technology. Our measurements all point in the same direction: as you go further than f/ 4 – to f /2 and wider, the accrued quantity of light falls marginally onto the sensor. A stronger and stronger part of this additional light is blocked or lost. I am therefore inclined to question the real benefit of faster lenses.”
."
Must be reffering to Canon sensors....
10-05-2016, 03:00 AM   #23
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Well the statement of Frédéric Guichard is valid for the case of high chief ray angle lenses. This is verified mainly for the following cases :
> Wide angle lenses
> Small size sensors with non-telecentric lenses (typical of smartphone industry).
Basically the thing is that the maximum admissible chief ray angle for a pixel is around 30°... A limitation inherent to the pixel technology, and not only to the brand ^^

As for the 50mm f/1.2 I find it usable on FF if you have some time to focus it (liveview can help) but would probably not be using it under f/1.8 iif I need to get the shot.

10-05-2016, 05:16 AM - 1 Like   #24
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QuoteOriginally posted by paulh Quote
I can't even see how AF at f/1.2 would be practical hand-held - even the slightest movement would throw it off. Of course on a tripod it would be a different story - but then on a tripod manual focus might be preferable anyway.
At 105mm and f1.4 the DOF should be similar to the 85mm f1.2 lenses. We have a very good photographer in Romania who's reviewing for Nikon Romania the new lens arrived to the table - Nikon 105mm f1.4

He's a photojurnalistic type of photographer and for these images (see in the link below some images at f1.4 and 105mm) he didn't use a tripod. You have to be an experienced photographer to handle the tiny DOF at 85mm or 105mm and I also want to mention that not everybody likes the look of the f1.2 or f1.4 lenses.

Nikon 105/1,4 - obiectivul acesta va... - Mircea Bezergheanu | Facebook

And below it's a portrait of an authentic romanian peasant (same photographer as above), taken at 105mm f1.4. I admit that I don't always like portraits taken at f1.2 or f1.4, but this image speaks for itself.

https://www.facebook.com/photo.php?fbid=10207529091804665&set=pb.1210472777....type=3&theater

Last edited by Dan Rentea; 10-05-2016 at 06:05 AM.
10-05-2016, 10:02 AM   #25
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QuoteOriginally posted by Kerrowdown Quote
What and take away the frustration of missing focus manually.
Exactly!

The DA* 55/1.4 is only f1.4 so it completely fails on bragging rights. But plug its numbers into a depth of field calculator and notice it has just slightly less DOF wide open than a 50/1.2. My copy comes with the thrill of manual focusing until it finally wakes up - it's like a frat boy on a weekend. Pictures are great, weather sealing is great, you just won't win any gear-measuring contests.
10-05-2016, 12:48 PM   #26
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QuoteOriginally posted by Just1MoreDave Quote
Exactly!
We all know it's all about bragging rights as you so rightly point out.
10-05-2016, 02:41 PM   #27
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QuoteOriginally posted by Dan Rentea Quote
And below it's a portrait of an authentic romanian peasant (same photographer as above), taken at 105mm f1.4. I admit that I don't always like portraits taken at f1.2 or f1.4, but this image speaks for itself.
I'm not sure that if this shot was mine that I'd wouldn't have wished I'd opened up the lens a bit... maybe a stop?
10-05-2016, 03:01 PM   #28
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QuoteOriginally posted by noelpolar Quote
I'm not sure that if this shot was mine that I'd wouldn't have wished I'd opened up the lens a bit... maybe a stop?
Good for the novelty value, though, Noel.

I toyed with the idea of hunting down a K50 f1.2 (the bokeh in shots I've seen is like an oil painting), but decided to be practical and go for the DA*55. For it, I reckon f2 is a good sweet spot balancing bokeh, 3D separation, sharpness, etc.
10-05-2016, 03:02 PM - 1 Like   #29
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QuoteOriginally posted by Dan Rentea Quote
At 105mm and f1.4 the DOF should be similar to the 85mm f1.2 lenses. We have a very good photographer in Romania who's reviewing for Nikon Romania the new lens arrived to the table - Nikon 105mm f1.4
Thanks for posting these, Dan ... it's always interesting to see someone bothering to push the limits of these things.

Here's a Melbourne example:

Using Sony A7 II + Mitakon 50mm F0.95 for Wedding Photography | Melbourne Wedding Photographer Will Chao
10-05-2016, 03:47 PM   #30
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QuoteOriginally posted by clackers Quote
Good for the novelty value, though, Noel.

I toyed with the idea of hunting down a K50 f1.2 (the bokeh in shots I've seen is like an oil painting), but decided to be practical and go for the DA*55. For it, I reckon f2 is a good sweet spot balancing bokeh, 3D separation, sharpness, etc.
F2 is where I start to use the K50/1.2 mostly.... I am quite fond of it...
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