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03-09-2016, 07:34 AM   #1
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Program line logic

Is anybody more expirienced in using program lines of K-3 or K-3II ( I have K-3II but probably that part is identical).

I programed one of the user modes to be in Av exposure mode, auto ISO range from 100-10000 with fast ISO parameter (one that changes ISO actively), and under program line I selected high speed priority. EV compensation is -0,7.

So if I pick f2.8, for a given scene which is not important, camera chooses ISO of 1250 and shutter speed of 1/80. But when I close the aperture to f3.2, camera goes up to 1600 and speeds up the shutter to 1/100 where it will stay until f8 when it goes back to 1/80. At that poing ISO will be at 10000 and any further closing of the aperture wil result in slower and slower shutter speeds, which is ok and logical.

Problem I am having is that I would like the shutter to be at least 1/125 without touching any controls, and why is camera using lower ISO and slower shutter speed at f2.8 than at f3.2. I noticed that changing ISO paramaters to normal and slow, totally ignores the high speed program line for the same sceen. So if I choose slow ISO paramater camera will go to ISO400 put shutter speed of 1/20 which is far from being fast and not so easy to shoot with when running around people trying to capture spontaneous moments (even if SR does the job by somewhat eliminating my shaky hands, people do move).

On the other hand there is no difference in exposures when changing between auto, normal and high shutter speed priority program lines, camera chooses same elements for the same scene. ( two DOF program lines are not usable with camera set to Av so I did not test those two and MTF is ignored because I use Sigma lens). I tried saving a profile with each of those changes and turning camera off and on again to see if that will make another calculation, but id didn't.
I also tried setting the camera to Tv and program line to large DOF, it will stay at f2.8, camera chooses not to close the aperture even if user prefers large DOF even though it has the room to ramp up the ISO with the range I programed to be. Really odd choices.

Choosing TAv is almost like manual mode which is not the best choice. If only there was a minimum shutter speed limiter, that would solve my problems.

03-09-2016, 09:59 AM - 2 Likes   #2
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QuoteOriginally posted by zvon Quote
Problem I am having is that I would like the shutter to be at least 1/125 without touching any controls, and why is camera using lower ISO and slower shutter speed at f2.8 than at f3.2.
Turn off auto ISO. That will give the camera head room to follow the pure program line. Your question comes up periodically on this site and always in the context of wanting the camera to float above an intended low limit for shutter speed. Unfortunately, that sort of functionality is not available and I am not even sure it is a good idea (many reasons). Using the high speed program line should provide something similar except that auto-ISO overlays an additional set of priorities and rules that take priority over the program line. This is hard to explain except to state what I have long felt, that in general auto-ISO is evil.


Steve
03-09-2016, 04:54 PM - 1 Like   #3
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I'm usually in TAv mode for good light and stationary subjects, Zvon, but don't hesitate to go full manual at other times.


You know what you want to achieve, so the program lines in your head are more relevant than the ones built into any camera.
03-10-2016, 02:37 AM   #4
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QuoteOriginally posted by stevebrot Quote
Turn off auto ISO. That will give the camera head room to follow the pure program line. Your question comes up periodically on this site and always in the context of wanting the camera to float above an intended low limit for shutter speed. Unfortunately, that sort of functionality is not available and I am not even sure it is a good idea (many reasons). Using the high speed program line should provide something similar except that auto-ISO overlays an additional set of priorities and rules that take priority over the program line. This is hard to explain except to state what I have long felt, that in general auto-ISO is evil.


Steve

ok, but that setup will have two fixed variables (ISO and aperture) and that leaves just one possible shutter speed, no matter what program line you would choose, shutter speed would be exactly the same every time. I tried it and I could use it like that, to speed up the shutter I should manually bump the ISO, it is kind of a good workaround. I am just trying to be capable of capturing stuff in that are happening in pretty extreme cases so I can focus on making good photos. I am probably asking too much from program lines by trying to make them work in every extreme case as I should want.


QuoteOriginally posted by clackers Quote
I'm usually in TAv mode for good light and stationary subjects, Zvon, but don't hesitate to go full manual at other times.


You know what you want to achieve, so the program lines in your head are more relevant than the ones built into any camera.
I am using manual 80% of the time, especially in cases you described. I am no stranger to that. But sometimes I would like to use the automatics of the camera because you can't be faster than camera in choosing settings if your current picture calls for ISO100, f5.6, and 1/250 speed and the next one is asking for ISO3200, f2.8 and 1/80 or something like that. Extreme cases in any way. For example 5d3 has the ability to set the lowest shutter speed that you are willing to use.

03-10-2016, 05:21 AM   #5
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I think that the main program line setting only operates in program mode; however you might possibly get closer to what you want by customising an e-dial to select your preferred program line in a specific exposure mode by pressing the green button.
03-10-2016, 06:46 AM   #6
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QuoteOriginally posted by zvon Quote
Is anybody more expirienced in using program lines of K-3 or K-3II ( I have K-3II but probably that part is identical).

I programed one of the user modes to be in Av exposure mode, auto ISO range from 100-10000 with fast ISO parameter (one that changes ISO actively), and under program line I selected high speed priority. EV compensation is -0,7.

So if I pick f2.8, for a given scene which is not important, camera chooses ISO of 1250 and shutter speed of 1/80. But when I close the aperture to f3.2, camera goes up to 1600 and speeds up the shutter to 1/100 where it will stay until f8 when it goes back to 1/80. At that poing ISO will be at 10000 and any further closing of the aperture wil result in slower and slower shutter speeds, which is ok and logical.

Problem I am having is that I would like the shutter to be at least 1/125 without touching any controls, and why is camera using lower ISO and slower shutter speed at f2.8 than at f3.2. I noticed that changing ISO paramaters to normal and slow, totally ignores the high speed program line for the same sceen. So if I choose slow ISO paramater camera will go to ISO400 put shutter speed of 1/20 which is far from being fast and not so easy to shoot with when running around people trying to capture spontaneous moments (even if SR does the job by somewhat eliminating my shaky hands, people do move).

On the other hand there is no difference in exposures when changing between auto, normal and high shutter speed priority program lines, camera chooses same elements for the same scene. ( two DOF program lines are not usable with camera set to Av so I did not test those two and MTF is ignored because I use Sigma lens). I tried saving a profile with each of those changes and turning camera off and on again to see if that will make another calculation, but id didn't.
I also tried setting the camera to Tv and program line to large DOF, it will stay at f2.8, camera chooses not to close the aperture even if user prefers large DOF even though it has the room to ramp up the ISO with the range I programed to be. Really odd choices.

Choosing TAv is almost like manual mode which is not the best choice. If only there was a minimum shutter speed limiter, that would solve my problems.
I think what you're asking for is something Fuji cameras do... Auto ISO requires a minimum shutter speed input by the user. I can see some advantages to this approach and some disadvantages, too (such as making more sense with a prime lens and not a zoom). It probably depends on what you're trying to do on any given day.
03-10-2016, 10:09 AM   #7
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QuoteOriginally posted by zvon Quote
ok, but that setup will have two fixed variables (ISO and aperture) and that leaves just one possible shutter speed, no matter what program line you would choose
P-mode with manual override if needed (so-called hyper-program feature). That is what I use when I am unable to give full attention to managing the camera settings and want to use the program line. As mentioned above, non-ambiguous program line behavior only happens with auto-ISO turned off. It is not immediately obvious, but the program line is based on EV (shutter/aperture combination) in the strictest sense only. Auto-ISO is not part of the base program, but has its own rules accessible through the menu settings. The current ISO setting drives the program line (not the other way around) and all bets are off when that setting changes automagically. If you desire less meddling, change the auto-ISO setting to normal or "slow". (The setting names are unfortunate and not related to still-life vs. action photography.)

I agree that a minimum shutter speed menu setting is an excellent idea. Most users would never use it, but those that might would appreciate the option. If it helps any, you are not the first user who has expressed a desire for such.


Steve

(...things get real interesting when P-TTL flash is in the mix under mixed lighting...)

Last edited by stevebrot; 03-10-2016 at 10:21 AM.
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