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12-30-2015, 08:46 AM   #106
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QuoteOriginally posted by Cynog Ap Brychan Quote
As I understand it, total light differs from lumens per square centimeter.
Of course it does, it's lumens per square centimeters
Pretty useless, most of the time.

12-30-2015, 09:03 AM   #107
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QuoteOriginally posted by Kunzite Quote
Of course it does, it's lumens per square centimeters
Pretty useless, most of the time.
Useful when 35x23 propagandists want to do a snow job on unsuspecting smaller format users, who don't know any better. It took me years to figure out the nonsense they were posting about "total light". I knew it was irrelevant deep down in my heart, I just couldn't for the life of me figure out why. Even after falconeye gave me a hint, I still couldn't get it.

Last edited by normhead; 12-30-2015 at 10:10 AM.
12-30-2015, 09:50 AM   #108
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I'm not being sarcastic here, but can someone refresh my memory as to why FF consistently gets significantly better noise measurements than APS-C? I thought that the concept of "total light" has been sort of implicitly accepted, even if not specifically under that particular terminology.
12-30-2015, 09:58 AM   #109
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QuoteOriginally posted by bxf Quote
why FF consistently gets significantly better noise measurements than APS-C?
Bigger pixels!
Also newer sensors are better than older sensors.

12-30-2015, 10:05 AM   #110
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QuoteQuote:
I'm not being sarcastic here, but can someone refresh my memory as to why FF consistently gets significantly better noise measurements than APS-C?
Because they don't normalize the DoF. Remember 35x23 is one stop shallower DoF. SO if you stop the 35x23 down to achieve the same DOF, and maintain shutter speed, you have to increase the ISO one stop, and both your total light and noise advantage are gone. The whole "better in low light" , "total light" advantage is predicated on using settings that give you narrower DOF. It;s been a slight of hand used by 35x23 protagonists for years.

Equivalence actually proves equivalence, not an advantage for one over the other.

The advantage to 35x23 is one stop shallower depth of field wide open, coupled with one stop better noise, shooting wide open. In any other circumstance, there is not advantage. People talk about wider angle shots looking more natural, there's a window where an FF image shot for narrow DOF looks quite a bit better than an APS-c shot at 35mm.. there are other advantages, but most of the other advantages are offset by higher pixel density of APS-c creating the illusion of more reach.

Because of the smaller pixels for equivalent APS_c the one stop more DoF at the long end, you'd expect to be an advantage for APS-c really doesn't exist. Shooting ƒ32 on APS-c to get that extra stop is so diffraction limited, it's not really an option.

Last edited by normhead; 12-30-2015 at 10:33 AM.
12-30-2015, 10:10 AM   #111
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QuoteOriginally posted by UncleVanya Quote
I think the point originally made is you get true 55mm using full FF image (assuming the 55-300 is FF capable which I think someone indicated but I can't confirm) and by switching to Crop mode you get effectively 450mm coverage. So the lens on that body covers a wider range than we are used to by engaging the crop mode when you need the reach. The reality is that you can always just crop in post from the FF size and get the same results - that's often lost in these discussions.
When the DA 55-300 was first made, Pentax labeled it for digital and their digital was APS-C. It "may" cover the FF image circle somehow, but the point is that time it was made, Pentax was purely APS-C. So I think it cannot be safe to assume and say it has a "crop equivalent" of 450mm when it was designed for a system and labeled properly as 55-300mm too. It's the other way around. Sounds confusing but it isn't, if basing it from that point in time when majority of Pentax glass were purely APS-C
12-30-2015, 10:36 AM   #112
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QuoteQuote:
The reality is that you can always just crop in post from the FF size and get the same results - that's often lost in these discussions.
That's not the reality if you own a K-3, I didn't lose sight of it, it's not there. I will always have more resolution shooting with my K-3 than you will shooting a 36 MP 35x23 camera in crop. Which is why if I ever buy a K-1, it will be in the bag, waiting for a nice landscape, while the K-3 and 60-250 will begin my hand, hoping for wildlife. Hopefully the K-1 will exceed the K-5 in dynamic range, I want my 1 EV back and then some.
12-30-2015, 11:04 AM - 1 Like   #113
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QuoteOriginally posted by Alizarine Quote
When the DA 55-300 was first made, Pentax labeled it for digital and their digital was APS-C. It "may" cover the FF image circle somehow, but the point is that time it was made, Pentax was purely APS-C. So I think it cannot be safe to assume and say it has a "crop equivalent" of 450mm when it was designed for a system and labeled properly as 55-300mm too. It's the other way around. Sounds confusing but it isn't, if basing it from that point in time when majority of Pentax glass were purely APS-C
It's 55-300mm on a FF. It's 55-300mm on a Q. It's 55-300mm on APS-c. Its focal length is an inherent property of the lens that has nothing to do with what's behind it. It's labeled correctly.

IF it covers FF at the long end, it will have the same field of view on FF as an ancient 300mm m42 takumar does on FF.


Last edited by BrianR; 12-30-2015 at 11:16 AM.
12-30-2015, 11:55 AM   #114
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Probably a thick question but if 32mp at FF translates to 16mp and APS-C, why don't they make a 24mp APS-C sensor bigger - more mp across the FF format then.
12-30-2015, 11:58 AM   #115
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QuoteOriginally posted by redimp Quote
Probably a thick question but if 32mp at FF translates to 16mp and APS-C, why don't they make a 24mp APS-C sensor bigger - more mp across the FF format then.
By "bigger", do you mean "having more MP"?
12-30-2015, 12:03 PM   #116
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QuoteOriginally posted by redimp Quote
Probably a thick question but if 32mp at FF translates to 16mp and APS-C, why don't they make a 24mp APS-C sensor bigger - more mp across the FF format then.
36MP FF cropped to APS-C is 16MP
12-30-2015, 12:06 PM   #117
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QuoteOriginally posted by redimp Quote
Probably a thick question but if 32mp at FF translates to 16mp and APS-C, why don't they make a 24mp APS-C sensor bigger - more mp across the FF format then.
A 36 MP 35x23 translates to 15 MP APS-c, and Canon makes a 51 MP 35x23 that would be roughly equivalent to a 24 MP APS-c if it were cropped, but it's $7K.
12-30-2015, 12:12 PM   #118
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QuoteOriginally posted by zmohie Quote
Pentax: "while displaying a cropping frame in the camera’s viewfinder."
I hope they are not using a complete blackout crop. It would be nice to see what is coming from outside the frame to the center even incases where image quality is not superb. A little bit of rangefinder feeling.
12-30-2015, 12:19 PM   #119
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This could have been suggested already but Pentax should add an APS-H crop option as well. It can be done as it falls between FF and APS-C. Some DA lenses sweet spot may fall at APS-H size. Like several of the DA LTD's.

Isn't this all really moot though in the sense that why crop a FF sensor? I understand the need for cropping when a true APS-C lens is being used. But for lenses like the DA*55 DA*300 DA 560 used in the teaser shooting FF them cropping it later if need be should be the way to go.
12-30-2015, 12:20 PM   #120
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QuoteOriginally posted by reh321 Quote
By "bigger", do you mean "having more MP"?
Both as in bigger sensor equates to more mp. Going on the correct figures, a K-5 APS-C sensor scaled up to FF would have 36mp. Therefore, if they are making a APC-C sensor with 24mp in the K-3, why not scale this up to give higher mp in the FF and 24mp in crop mode?
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