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09-14-2017, 02:40 AM   #1
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Program Line mode related to the Green Button?

Ok.. I am a bit slow on the uptake, but I take it when pressing the green button to 'reset' things (correct exposure), depending upon the mode the 'Program Line' is in (that is if you actually get a choice, ie User modes etc), then the 'algorithm' or whatever it uses to determine what to adjust (shutter, aperture and ISO) changes depending upon what Program Line yer in? For example, if you sway away from Normal or Auto and instead pick the action fast running guy symbol, then it tries to keep the shutter speed high and compensate with ISO and aperture for correct exposure? Likewise if choosing second last one, the one with bokeh emphasized the most, it will keep aperture wide open as possible and adjust ISO and shutter speed accordingly for correct exposure?

If setting up User modes, and one is 'Portrait' and the other 'Action' then it might make sense to have the correct corresponding Program Line modes for these custom User Modes yer building yeh? That way when yer hitting the green button in those modes you might be adjusting things 'less' than if left to it's own devices (Auto or Normal)?

Also, MTF mode, that seems to be trying to give you the sharpest image possible, therefore, in good lighting, can you actually find out where the sharpest aperture is on a lens by using this Program Line and hitting the green button?

Did i explain myself properly? lol

Cheers,

Bruce

09-14-2017, 03:06 AM   #2
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Yes, the green button sets according to the selected program line. Note that the programs still have lattitude depending on the lighting conditions - for example, even if you have it set to maximum depth of field, if the light is low the camera will open up the aperture until the exposure time is 1/fl. It seems like the "sport" line will decrease exposure time to 1/ 2xfl first, then get the aperture to MTF, then continue shortening the exposure time.

Last edited by Giklab; 09-14-2017 at 03:14 AM.
09-14-2017, 06:32 AM - 1 Like   #3
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Yes, except for your last paragraph. The camera program line doesn't know the "sharpest" aperture from one lens to another. But for MTF in good lighting, when using green button will, in my experience, default to f/5.6 to f/8. Which as a general rule tends to be a sweet spot for most lenses.
09-14-2017, 06:55 AM - 1 Like   #4
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QuoteOriginally posted by twilhelm Quote
Yes, except for your last paragraph. The camera program line doesn't know the "sharpest" aperture from one lens to another. But for MTF in good lighting, when using green button will, in my experience, default to f/5.6 to f/8. Which as a general rule tends to be a sweet spot for most lenses.
The camera does know the sharpest aperture for each lens (as long as it has the proper contacts), and MTF line will aim to select it when it calculates exposure. Not always possible to do so and keep the Shutter speed/ISO withing reasonable limits in which case it will choose an aperture close to it.

09-14-2017, 08:48 AM   #5
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09-14-2017, 09:58 AM   #6
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QuoteOriginally posted by BruceBanner Quote
Also, MTF mode, that seems to be trying to give you the sharpest image possible, therefore, in good lighting, can you actually find out where the sharpest aperture is on a lens by using this Program Line and hitting the green button?
Pretty much, though this only works for FA lenses and newer (this includes all digital-era DA and D FA lenses of course).

QuoteOriginally posted by BruceBanner Quote
Ok.. I am a bit slow on the uptake, but I take it when pressing the green button to 'reset' things (correct exposure), depending upon the mode the 'Program Line' is in (that is if you actually get a choice, ie User modes etc), then the 'algorithm' or whatever it uses to determine what to adjust (shutter, aperture and ISO) changes depending upon what Program Line yer in? For example, if you sway away from Normal or Auto and instead pick the action fast running guy symbol, then it tries to keep the shutter speed high and compensate with ISO and aperture for correct exposure? Likewise if choosing second last one, the one with bokeh emphasized the most, it will keep aperture wide open as possible and adjust ISO and shutter speed accordingly for correct exposure?
Yes, it will snap back to whatever settings the camera would have used if you did not manually change the shutter speed or aperture. The ISO curve is controlled via a separate menu setting.

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09-14-2017, 12:15 PM   #7
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QuoteOriginally posted by twilhelm Quote
Yes, except for your last paragraph. The camera program line doesn't know the "sharpest" aperture from one lens to another. But for MTF in good lighting, when using green button will, in my experience, default to f/5.6 to f/8. Which as a general rule tends to be a sweet spot for most lenses.
QuoteOriginally posted by pschlute Quote
The camera does know the sharpest aperture for each lens (as long as it has the proper contacts), and MTF line will aim to select it when it calculates exposure. Not always possible to do so and keep the Shutter speed/ISO withing reasonable limits in which case it will choose an aperture close to it.
So one says yes it does, the other peson says no it doesn't (but gives an f stop close to it)... who to believe!? hehehe

I was just messing with the program line indoors with my FA50mm 1.4 attached, and it was dimly lit indoors and when selecting the MTF Program Line the lens only went to f2.0 (but all other Program Lines green buttoned it to f1.4), so I knew it was 'trying' but as you say "Not always possible to do so..."

QuoteOriginally posted by Adam Quote
Pretty much, though this only works for FA lenses and newer (this includes all digital-era DA and D FA lenses of course).



Yes, it will snap back to whatever settings the camera would have used if you did not manually change the shutter speed or aperture. The ISO curve is controlled via a separate menu setting.
So I wonder, can you create ideal lighting (consistent, so perhaps Studio etc) and test lenses out? Has anyone done this and reported back/created a database with what MTF mode is determining what the sharpest Aperture of the lenses tested turned out to be? I'm imagining that just waiting for a 'nice sunny day' to test what the green button gives back when using MTF is just too inconsistent, and that to be more objective it would be better to set up a nice artificially lit room (camera tripodded) to create enough light for the MTF exposure to work best? When calculating 'Sharpness' I take it means edge to edge? or....
09-14-2017, 12:45 PM - 1 Like   #8
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QuoteOriginally posted by BruceBanner Quote
So one says yes it does, the other peson says no it doesn't (but gives an f stop close to it)... who to believe!? hehehe
Why not believe the k1 manual page 46:

"MTF Priority: Sets the sharpest aperture of the attached lens when a D FA, DA, DAL, FA, or FA J lens is used."

09-14-2017, 12:49 PM   #9
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QuoteOriginally posted by pschlute Quote
Why not believe the k1 manual page 46:

"MTF Priority: Sets the sharpest aperture of the attached lens when a D FA, DA, DAL, FA, or FA J lens is used."
haha, I'm sold
09-14-2017, 12:56 PM   #10
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QuoteOriginally posted by BruceBanner Quote
I'm imagining that just waiting for a 'nice sunny day' to test what the green button gives back when using MTF is just too inconsistent, and that to be more objective it would be better to set up a nice artificially lit room (camera tripodded) to create enough light for the MTF exposure to work best? When calculating 'Sharpness' I take it means edge to edge? or..
if you want to know how sharp (or other qualities of a lens) look at a lens review. You will learn more from that than an unscientific test. Most lenses are sharpest from f4-f8, but there is a difference between centre and edge sharpness which is usually seen in the test reviews. So a lens may be sharpest centre at say f4 but with very weak edges. But at f5.6 the cenrtre may be just marginaly less sharp but with much improved edges that eclipse the dge sharpness at f4. So my rhetorical question to you is ...where is the lens sharpest...f4 or f5.6 ? I know which I would want to use if shooting a wide image.
09-14-2017, 01:05 PM - 1 Like   #11
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QuoteOriginally posted by pschlute Quote
if you want to know how sharp (or other qualities of a lens) look at a lens review. You will learn more from that than an unscientific test. Most lenses are sharpest from f4-f8, but there is a difference between centre and edge sharpness which is usually seen in the test reviews. So a lens may be sharpest centre at say f4 but with very weak edges. But at f5.6 the cenrtre may be just marginaly less sharp but with much improved edges that eclipse the dge sharpness at f4. So my rhetorical question to you is ...where is the lens sharpest...f4 or f5.6 ? I know which I would want to use if shooting a wide image.
I do tend to look at reviews of lenses here (especially before buying), but they do sometimes differ in opinion, and one may say sharpness is 'here' and another something different. That's why I wondered if there was a more accurate 'test' that could be performed, with trying to keep the environment controlled light wise and using MTF as a way of determining what the camera thought was the sharpest f number.
And you brought up my second point about how does MTF determine the sharpest, in the middle or edge to edge?

But after rereading your post I see you are really meaning those indepth lens reviews, the ones with charts etc and proper testing (rather than average joe bloggs impression/reviews). Yep, makes sense
09-15-2017, 11:03 AM - 1 Like   #12
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QuoteOriginally posted by BruceBanner Quote
I do tend to look at reviews of lenses here (especially before buying), but they do sometimes differ in opinion, and one may say sharpness is 'here' and another something different. That's why I wondered if there was a more accurate 'test' that could be performed, with trying to keep the environment controlled light wise and using MTF as a way of determining what the camera thought was the sharpest f number.
And you brought up my second point about how does MTF determine the sharpest, in the middle or edge to edge?

I assume the MTF data is programmed into the lens at the factory, probably based on testing, on a lens model basis (as opposed to an individual lens copy basis).

So the MTF program line will select the aperture with the best resolution that is possible with the current lighting -- EXCEPT in the case of the DA*55. That lens seems to have a special program line where it tries to the smallest aperture, instead of the MTF-optimized one. Presumably this is because of the intended use of that lens as a portrait lens, so it is trying to give you a shallow DOF appropriate for a portrait. Not sure if any other lens behave this way; it is the only one I have noticed.
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