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12-29-2015, 05:50 PM   #91
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QuoteOriginally posted by normhead Quote
f you're planning to shoot at ƒ5.6 or higher, carrying ƒ2.8 lenses is beyond dumb.
You know this flies in the face of the fact that a vast majority of f/2.8 zoom lenses perform almost as well as primes across the frame when stopped down two stops. I know plenty of hiking and adventure photographers who use f/2.8 zoom lenses because there are too many compromises involved with slower f/4 lenses* to warrant the lighter weight.

*such as being able to be used with teleconverters, needing to use High ISOs to compensate for the loss in lens speed, dimmer viewfinder,AF sensor precision limits on certain cameras.

12-29-2015, 07:36 PM   #92
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QuoteOriginally posted by Digitalis Quote
You know this flies in the face of the fact that a vast majority of f/2.8 zoom lenses perform almost as well as primes across the frame when stopped down two stops. I know plenty of hiking and adventure photographers who use f/2.8 zoom lenses because there are too many compromises involved with slower f/4 lenses* to warrant the lighter weight.

*such as being able to be used with teleconverters, needing to use High ISOs to compensate for the loss in lens speed, dimmer viewfinder,AF sensor precision limits on certain cameras.
brighter ovf is also really nice on extension tubes for macro... da* 55 1.4 does well.
12-29-2015, 08:20 PM   #93
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QuoteOriginally posted by Digitalis Quote
The evidence of the existence of a squirrel mode is mounting..
QuoteOriginally posted by jatrax Quote
And somewhat disturbing, on several levels.....
QuoteOriginally posted by pathdoc Quote
There will be no battery compartment - just a place to put the peanuts in.
Well, try to remember that Otis is a big Pentax and PForum fan, has donated to make a good many Members "Loyal Site Supporters" and many others Site Supporters ........he is always there to defend the brand and help out if called upon. Can't be all bad...can it?

I have a question.....may be not so bright, but I didn't spend anytime thinking it over when it is just easier to ask you guys.....

Since I assume the FF will give better low noise results, will this also translate to my shots when shooting in the cropped mode?

Regards!
12-29-2015, 08:34 PM   #94
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QuoteOriginally posted by Rupert Quote
Since I assume the FF will give better low noise results, will this also translate to my shots when shooting in the cropped mode?
Depends mainly on pixel size, you unbright old man! (I'm joking )

12-29-2015, 09:00 PM   #95
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Otis said that is not joking, just honesty on your part......

Well, after thinking about it.....if the FF shot has less noise, then it should follow that the crop would have less noise....in comparison to my K5IIs? I'm not fishing for the Otis "Big Brain Award".......not much chance I'll ever get one of those.

What do you think?

Regards!
12-29-2015, 09:55 PM   #96
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If we assume that the K-1's crop mode gives 16 MP like the K-5IIs, then it would hopefully still have less noise than the K-5IIs just due to using newer technology... but we wouldn't know that until the test results came out. But either way, the FF mode would give lower noise still, assuming you view both shots at the same resolution/size (because the greater magnification the cropped shot would go through makes the noise more apparent).
12-30-2015, 12:00 AM   #97
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QuoteOriginally posted by Scintilla Quote
If we assume that the K-1's crop mode gives 16 MP like the K-5IIs, then it would hopefully still have less noise than the K-5IIs just due to using newer technology... but we wouldn't know that until the test results came out. But either way, the FF mode would give lower noise still, assuming you view both shots at the same resolution/size (because the greater magnification the cropped shot would go through makes the noise more apparent).
If you print at 300dpi, that's the resolution. If every twentieth pixel is noise, that's the same whether cropped or FF.

You'll only tell a difference if you blow the crop up beyond 300.

It should be trivial to work out what that size is for a 16Mp image.
12-30-2015, 12:51 AM   #98
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QuoteOriginally posted by Rupert Quote
Well, try to remember that Otis is a big Pentax and PForum fan, has donated to make a good many Members "Loyal Site Supporters" and many others Site Supporters ........he is always there to defend the brand and help out if called upon. Can't be all bad...can it?

I have a question.....may be not so bright, but I didn't spend anytime thinking it over when it is just easier to ask you guys.....

Since I assume the FF will give better low noise results, will this also translate to my shots when shooting in the cropped mode?

Regards!
I'm also asking is a crop lens like a da f2.8 still f2.8 when using on full frame?
I mean is the aperture of crop and full frame lenses are equal on full frame. .for instance fa 50 mm f 1. 4 and da 55 mm f 1.4?

12-30-2015, 01:12 AM   #99
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What else could it be?
The lens' optical properties are the same regardless if it's on a camera - any camera - or not. It cannot "know" the format, nor change its optical properties in any way.
12-30-2015, 01:59 AM   #100
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I'll try to answer with what I've seen and understand (maybe I'm wrong though).

I think that in general FF sensors consist from different photosites and are bigger and brighter than the cropped ones. So the cropped FF image using the ~16Mpxl area should give a brighter and less noisy image than the APS-C same sized sensors.

Camera sensor size: Why does it matter and exactly how big are they?

Also concerning the question: "is the aperture of crop and full frame lenses are equal on full frame".

The aperture is the same as given for the lens (an F/2 lens on 4/3 cameras are indeed F/2) as it is proportion of the light falling on the sensor. What changes though is the DOF that you need to multiply with the crop factor to find how the image would compare to the 35mm FF format. So an F/1.4 lens of FF gives a specific DOF while the same lens on a APS-C will still be a bright F/1.4 but the DOF will be like 1.4*1.5 = F/2.1 in the FF!

I hope I've helped my English don't help me express myself properly!

12-30-2015, 05:41 AM   #101
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QuoteOriginally posted by zmohie Quote
I'm also asking is a crop lens like a da f2.8 still f2.8 when using on full frame?
I mean is the aperture of crop and full frame lenses are equal on full frame. .for instance fa 50 mm f 1. 4 and da 55 mm f 1.4?
Yes. And if the exposure for your K-3 with DA*55 for a scene is f1.4, ISO100, 1/250s, for your new FF with FA50 the exposure is f1.4, ISO100, 1/250s.

So much for 'Total Light'.
12-30-2015, 06:25 AM   #102
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QuoteOriginally posted by clackers Quote
If you print at 300dpi, that's the resolution. If every twentieth pixel is noise, that's the same whether cropped or FF.

You'll only tell a difference if you blow the crop up beyond 300.

It should be trivial to work out what that size is for a 16Mp image.
My apologies if I wasn't clear. When I said "resolution/size", I meant either the dimensions of the image on a screen (not the DPI in a print) or the total size of the print, depending on which medium one cares about at any given moment.

If you wanted to print at (say) 24"x18", with a 36 MP sensor that would be just over 300 DPI. If you take the 16 MP crop and print it at the same size, you need just over 200 DPI. So if every twentieth pixel is noise, it'll be more apparent on the crop, because those pixels will be bigger.

I suspect we both already knew all this and we're just getting hung up over terminology.
12-30-2015, 06:47 AM   #103
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QuoteOriginally posted by clackers Quote
So much for 'Total Light'.
As I understand it, total light differs from lumens per square centimeter. Given the same light source, the bigger sensor will capture more photons to use for image formation, although the exposure settings may be the same, as you say. But I suspect you already know this.
12-30-2015, 08:04 AM   #104
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QuoteOriginally posted by redpit Quote
I'll try to answer with what I've seen and understand (maybe I'm wrong though).

I think that in general FF sensors consist from different photosites and are bigger and brighter than the cropped ones. So the cropped FF image using the ~16Mpxl area should give a brighter and less noisy image than the APS-C same sized sensors.

Camera sensor size: Why does it matter and exactly how big are they?

Also concerning the question: "is the aperture of crop and full frame lenses are equal on full frame".

The aperture is the same as given for the lens (an F/2 lens on 4/3 cameras are indeed F/2) as it is proportion of the light falling on the sensor. What changes though is the DOF that you need to multiply with the crop factor to find how the image would compare to the 35mm FF format. So an F/1.4 lens of FF gives a specific DOF while the same lens on a APS-C will still be a bright F/1.4 but the DOF will be like 1.4*1.5 = F/2.1 in the FF!

I hope I've helped my English don't help me express myself properly!

The size of the pixels of a 16mp FF are bigger, but if you have a 36mp FF and compare with a 16mp apsc you should find that the two have nearly identical pixel sizes. This is just a practical consequence of having the same number of pixels covering the same physical area.
12-30-2015, 08:34 AM   #105
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QuoteQuote:
I think that in general FF sensors consist from different photosites and are bigger and brighter than the cropped ones. So the cropped FF image using the ~16Mpxl area should give a brighter and less noisy image than the APS-C same sized sensors.
A 15-16 MP sensor ir a 15-16 MP crop sensor, doesn't matter if it's native APS-c or a 35x23 cropped in software to APS-c.

---------- Post added 12-30-15 at 10:39 AM ----------

QuoteQuote:
I know plenty of hiking and adventure photographers who use f/2.8 zoom lenses because there are too many compromises involved with slower f/4 lenses* to warrant the lighter weight.
I know guys who use Canon or Nikon 70-200s, those are the only ƒ2.8 images I know. And when I shoot my 60-250 ƒ4 with a 1.4 and they are shooting a 70-200 with a 2x, we are shooting practically identical images. So, I'm not with following.

As for the guys with the big huge telephotos, ya, I see them, in parking lots, after short walks to platforms, I've even seen one carry one of those beasts a couple hundred meters, to get from a parking lot to a bridge. I never see them where I go. I guess it just depends on what you call a hiking and adventure photographer. But then I just never see anyone where I go, most of the time, unless I brought them, so I guess that's kind of irrelevant.

I am curious what these problems I'm having with my 60-250 ƒ4 are though.

Last edited by normhead; 12-30-2015 at 08:58 AM.
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