K-5 "Program Line" setting

Started Mar 21, 2011 | Discussions
Eric O
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K-5 "Program Line" setting
Mar 21, 2011

Hello Pentaxians,

I could use more input and opinions about the "Program Line" setting in the K-5's camera menu. Please correct my current understanding of it and help me fill out the concept of what all of the settings do.

My understanding so far: Program Line sets the default aperture that the camera will select in any mode where the aperture is expected to be automatic. Also, in any situation where you have manually set an aperture (except perhaps Av and TAv?) if you press the "green button" the aperture will also be automatically adjusted in a way that respects the Program Line setting. Is this basically correct?

The "MTF" option for this setting should read MTF data from the lens, as long as the lens is capable and compatible to provide it, and therefore the camera will take the lens' sharpest apertures into account and prefer them when automatically adjusting aperture. Is my understanding correct here?

Also, does the MTF data tend to set a single aperture for a given lens, or perhaps it sets a function that associates a preferred aperture with each focal length? Also, would MTF suggest a range of preferred apertures for a given focal length or just a single one?

Is the camera willing to stray from the apertures suggested by its current Program Line setting? How willing? I assume if automatic EV compensation is turned on it will override it... I guess what I'm getting at with this question is, is it a weighted preference function like a bell curve, or does it just strictly peg your aperture, in situations where the aperture is automatically set, to a single specific stop?

The "sports" setting, indicated by a sprinting stick figure: does this tend to prefer smaller apertures (I mean, of course, below the diffraction limit) to help with sharpness in complicated sporting situations? Or does it follow the reasoning that a wider aperture will go with faster shutter speed and thus capture motion cleanly with no blur? Or does it go beyond those simple alternatives and take both into account?

The "greater DOF" setting indicated by a person in front of a mountain with both clear and sharp: This one seems pretty clear -- the camera should prefer smaller apertures (again, of course below the level of diffraction limiting) for a longer depth of focus. Correct?

Likewise the "shallower DOF" setting should do the opposite. I hope I'm right on at least these two. Unfortunately the two settings I understand most clearly, I am least likely to use, because I normally prefer P mode plus "hyper" manual aperture settings if I see a situation where I want to express something with an aperture priority. It would be rare that I would want to set the Program Line to always prefer a deeper or shallower DOF. Wouldn't I just be in Av or TAv or Manual mode in that case? That's another whole question -- please help me understand, is "Program Line" just the "lite" or "automatic shooter's" version of using an aperture priority mode? I am guessing that a manual, or mostly-manual, photographer would ignore Program Line completely unless perhaps its use via the Green Button could be seen as a convenience to quickly re-center the aperture after wide-ranging manual experimentation.

Finally, and perhaps the original thought that gave rise to this post in curiosity: Exactly what does the Program Line setting "Normal" do and how does that differ from "Auto"? I would be grateful if someone could explain the logic that the camera follows on each of these settings, and especially if anyone can give hypothetical situations or examples where one or the other would be more appropriate.

Sorry this is so long. Anyone who's not technically interested and feeling up for explaining stuff to me can just pass it by

  • Eric O.

Raphael Mabo
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Re: K-5 "Program Line" setting
In reply to Eric O, Mar 21, 2011

Eric O wrote:

My understanding so far: Program Line sets the default aperture that the camera > will select in any mode where the aperture is expected to be automatic.

No.
Program lines sets the aperture and shutter after a certain criteria.

In Av (aperture priority) and Tv (shutter priority) modes, program lines do nothing.
They also have nothing to do in TAv mode.

Program lines only functions when both aperture and shutter is set by the camera = in P mode/Hyper Program mode, in Sv mode, in Manual mode with green button (green button in M mode sets aperture and shutter after Program line setting if this is choosen).

Program lines are especially interresting to use with program shift, the behavior of program shift can be very different because of the program lines. (you set P mode to program shift instead of Hyper Program and you can set program shift to the other dial in Sv mode).

For example, if you have MTF mode on - then program shift feels more like aperture priority. If you have sports mode on, then program shift feels more like Tv mode.
But aperture and shutter still "floats" after the light situations.

The "MTF" option for this setting should read MTF data from the lens, as long as > the lens is capable and compatible to provide it, and therefore the camera will take > the lens' sharpest apertures into account and prefer them when automatically > adjusting aperture. Is my understanding correct here?

Correct.

Also, does the MTF data tend to set a single aperture for a given lens, or perhaps it > sets a function that associates a preferred aperture with each focal length? Also, > would MTF suggest a range of preferred apertures for a given focal length or just a > single one?

The lens gives the ideal aperture to the camera, and the MTF program line tries to be as close to this aperture as possible. So it is a weighted value, a curve.

It depends on the light situations and ISO if it is able to set the ideal aperture or not or how close it came.

Is the camera willing to stray from the apertures suggested by its current Program > Line setting?

There is no fixed value here. It tries the best it can according to the light situations.

The "sports" setting, indicated by a sprinting stick figure: does this tend to prefer > smaller apertures (I mean, of course, below the diffraction limit) to help with > sharpness in complicated sporting situations?

It tries to set as fast shutter as possible, and setting a fast shutter often means also setting a wide aperture.

The "greater DOF" setting indicated by a person in front of a mountain with both > clear and sharp: This one seems pretty clear -- the camera should prefer smaller > apertures (again, of course below the level of diffraction limiting) for a longer depth > of focus. Correct?

Yes. Smaller apertures - longer shutter speeds, for maximum depth-of-field.

It would be rare that I would want to set the Program Line to always prefer a deeper > or shallower DOF. Wouldn't I just be in Av or TAv or Manual mode in that case?

If that is what you want then yes.

That's another whole question -- please help me understand, is "Program Line" just > the "lite" or "automatic shooter's" version of using an aperture priority mode?

Program Lines are settings to "tune" the program mode to a certain behavior - favouring action shots, or close up shots or MTF ideal aperture shots, etc... It is to give more "intelligence" to the program mode, or a way for the user to have input on how program mode selects aperture and shutter.

Finally, and perhaps the original thought that gave rise to this post in curiosity: > Exactly what does the Program Line setting "Normal" do and how does that differ > from "Auto"?

The "Normal" setting is a generic standard curve, the only "logic" to that is that it tries to stay away from the lower shutter speeds in order to avoid camera shake. It is neither favouring smaller apertures or faster shutter speeds. It is a "middle of the road" mode.

"Auto" means that the camera automatic selects one of the program lines, to meet the certain shooting situation. It bases the selection upon parameters like distance info, light conditions, if the subject is moving or not, the focal length choosen and so on.
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Eric O
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Re: K-5 "Program Line" setting
In reply to Raphael Mabo, Mar 21, 2011

Raphael, thank you for another thoughtful and detailed answer. I'm afraid your first few paragraphs left me somewhat confused, because I thought I already expressed my understanding that Program Line would not affect any situation where the user has manually set an aperture value. But the rest is clearer to me now.

One more refinement: so Normal mode is already a type of automatic operation, and then Auto mode is... well... sort of an automatic operation with more artificial intelligence involved? Are you saying that Auto actually selects from among all of the other available Program Line settings to pick one for each situation? So Auto could actually choose Normal for a given shot, or any of the others?

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Raphael Mabo
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Re: K-5 "Program Line" setting
In reply to Eric O, Mar 21, 2011

Eric O wrote:

Raphael, thank you for another thoughtful and detailed answer. I'm afraid your > first few paragraphs left me somewhat confused, because I thought I already > expressed my understanding that Program Line would not affect any situation > where the user has manually set an aperture value.

But program line would also not affect any situation where the user has manually set a shutter value. Program lines controls aperture and shutter, never only aperture and never only shutter.

Aperture and shutter is linked.

If you set the aperture, you also has to set the shutter - if not, the exposure will change. So program lines sets both aperture and shutter, not only aperture and not only shutter.

One more refinement: so Normal mode is already a type of automatic operation, > and then Auto mode is... well... sort of an automatic operation with more artificial > intelligence involved?

"Normal" is a generic "middle of the road" program, like program mode for DSLR's or SLR's without program lines or picture modes. A "do it all" program.

"Auto" is the camera selecting between different program lines.

Are you saying that Auto actually selects from among all of the other available > Program Line settings to pick one for each situation?

Yes.

So Auto could actually choose Normal for a given shot, or any of the others?

Yes. Auto can choose "Normal" or any of the other program lines.

It typically sets "Normal" when none of the others are seem fitting for the situation, like it thinks "I haven't a clue right now, so I set 'normal' - that always works!".

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viking79
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Re: K-5 "Program Line" setting
In reply to Eric O, Mar 21, 2011

Eric O wrote:

One more refinement: so Normal mode is already a type of automatic operation, and then Auto mode is... well... sort of an automatic operation with more artificial intelligence involved? Are you saying that Auto actually selects from among all of the other available Program Line settings to pick one for each situation? So Auto could actually choose Normal for a given shot, or any of the others?

Yeah, "Green Mode" (full automatic) is a mode where you set the camera and if you grab the camera for a quick shot, you will get something decent. I don't think you even have the option to set the ISO on the newer cameras. It is basically a set of default camera parameters that are known good. If you hand the camera to a person that has never used a DSLR before, put it in green mode.

With P or Program Mode, it is also automatic, but can be bounded by how you configure the camera (like what program mode, etc). I don't use it a lot, but should as it is very flexible. There is no reason it couldn't replace both Av and Tv modes on the camera.

Edit: Sorry, I think I misunderstood your question a little. The "Auto" under program line tries to detect what program mode to use if I understand it correctly. Basically, it tries to determine if you want shallow depth of field, fast shutter speed, high MTF, etc. I don't know how it differs from normal. Maybe auto tries to guess at the mode and normal uses a set of specific values for a balance of MTF, depth of field, etc? If I had to wager a guess, I bet green mode puts the camera in Auto or normal automatically.

Eric
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Fogel70
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Re: K-5 "Program Line" setting
In reply to Raphael Mabo, Mar 21, 2011

Raphael Mabo wrote:

Eric O wrote:

Raphael, thank you for another thoughtful and detailed answer. I'm afraid your > first few paragraphs left me somewhat confused, because I thought I already > expressed my understanding that Program Line would not affect any situation > where the user has manually set an aperture value.

But program line would also not affect any situation where the user has manually set a shutter value. Program lines controls aperture and shutter, never only aperture and never only shutter.

Aperture and shutter is linked.

If you set the aperture, you also has to set the shutter - if not, the exposure will change. So program lines sets both aperture and shutter, not only aperture and not only shutter.

There is also something called ISO that the camera can control (if using auto-ISO).

If the camera can control two of the three parameters (aperture, shutter speed and ISO) program-line would be possible to use in any mode, but Pentax has chosen to only use it in program-modes (Hyper-P, P-shift and Sv) where the camera control both aperture and shutter speed.

Of course a PL that set shutter speed will not work in Tv-mode, or if PL set aperture it will not work in Av-mode. But IMO it would be a great feature if FI Tv-mode could be combined with MTF PL. Then the camera would priorities raising ISO before using "bad" apertures.

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shane gerrish
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Re: K-5 "Program Line" setting
In reply to Eric O, Mar 21, 2011

i thought the program line only affected the camera in p mode .

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13thBagel
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ISO is considered, too...
In reply to Raphael Mabo, Mar 21, 2011

Raphael Mabo wrote:

Aperture and shutter is linked.

If you set the aperture, you also has to set the shutter - if not, the exposure will change. So program lines sets both aperture and shutter, not only aperture and not only shutter.

(EDIT: I see others posted an ISO mention while I was composing the following...)

In addition to shutter speed and f-stop, it also takes ISO into account. For example, if you select "sports-line", the bias will be in favor of optimizing high shutter speed and increased DOF (via smaller f-stop), plus an increase in iso value so as not to push the shutter speed too high and f-stop too small for the lens you are using. All in all, it takes care of a lot of trial and error guess work... Pretty clever IMHO.

My basic settings are center-point focus with matrix metering on my K-5. I use P-mode and its various Program line options almost exclusively. In so doing, I relinquish some control over things, but its possible to over-ride the camera's recommendation using the AV, or TV wheels, or ISO button. During an over-ride, the camera's computer tries its best to adjust the other variables so you can still make the shot. My over-rides are mostly DOF (f-stop, or AV) related. More often than not, though, I just quickly size up the subject, hit the AF button, and let the camera figure out the rest. Works great!

Cheers...

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Raphael Mabo
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Re: K-5 "Program Line" setting
In reply to shane gerrish, Mar 21, 2011

Well yes it does, and green button in Manual mode (sets aperture and shutter according to program line), and aperture and shutter in Sv mode (which is basically P mode with manual ISO).
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Eric O
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Re: ISO is considered, too...
In reply to 13thBagel, Mar 22, 2011

Thanks to all who have replied. This is exactly the type of discussion I was looking for, and I have learned from every posted response. The biggest fact I was missing before my original post was where I didn't realize Program Line affects both aperture and shutter speed; I was thinking of it as merely targeting aperture. Now I understand better.

13thBagel, my basic settings and habits are the same as you describe. I typically keep the camera in P mode, but frequently alter either shutter speed or aperture when going for particular results in terms of DOF or motion stop (or lack of motion stop). Hyper-Program is wonderful for getting suggested settings in place and then quickly, flexibly adjusting them.

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Fogel70
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Re: ISO is considered, too...
In reply to Eric O, Mar 22, 2011

Eric O wrote:

Thanks to all who have replied. This is exactly the type of discussion I was looking for, and I have learned from every posted response. The biggest fact I was missing before my original post was where I didn't realize Program Line affects both aperture and shutter speed; I was thinking of it as merely targeting aperture. Now I understand better.

13thBagel, my basic settings and habits are the same as you describe. I typically keep the camera in P mode, but frequently alter either shutter speed or aperture when going for particular results in terms of DOF or motion stop (or lack of motion stop). Hyper-Program is wonderful for getting suggested settings in place and then quickly, flexibly adjusting them.

Hyper-P is great, but it would be even better if program-line was supported when changing aperture or shutter speed, but as it is now it will go back to "normal" program-line when setting is manually changed.

FI if using "sports" PL in Hyper-P the camera will choose shutter speed of maybe 1/500s or faster, but if changing aperture the camera go back using "normal" PL where shutter speed is set by focal length and you often end up with much slower shutter speed. So IMO program-line is pretty much useless in Hyper-P.

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alexius
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Re: K-5 "Program Line" setting
In reply to Raphael Mabo, Mar 22, 2011

WOW Raphael - a pleausure to read your answers ... I am totally new here - just got my K5 today and is still waiting for the battery to charge and now I know who to ask here - well guess thereĀ“s also others

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Raphael Mabo
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Re: ISO is considered, too...
In reply to Fogel70, Mar 22, 2011

Fogel70 wrote:

Hyper-P is great, but it would be even better if program-line was supported when > changing aperture or shutter speed, but as it is now it will go back to "normal" > program-line when setting is manually changed.

No, no program line is used when you set aperture or shutter.

This is because that when you set aperture - the camera sets the shutter after the light conditions, and when you set the shutter - the camera sets the aperture after the light conditions.

FI if using "sports" PL in Hyper-P the camera will choose shutter speed of maybe > 1/500s or faster, but if changing aperture the camera go back using "normal" PL > where shutter speed is set by focal length and you often end up with much slower > shutter speed.

But that is because your choosen aperture is too small for the current light conditions. If you open up the aperture, the shutter speed will be faster.

If the camera would choose a fast shutter speed with a small aperture here then the image would be underexposed.

When you open up aperture - shutter speed gets faster.
When you close down aperture - shutter speed gets slower.
When you set a faster shutter speed - aperture opens up.
When you set a slower shutter speed - aperture closes down.

This is to retain the same exposure value.

So say that you have light conditions that says

aperture f/2.8 and shutter 1/500 for good exposure, then f/4 with 1/250 and f/2 with 1/1000 gives same exposure as f/2.8 and 1/500.

When you reset the values by green button, the aperture and shutter are set after the choosen program line.

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Fogel70
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Re: ISO is considered, too...
In reply to Raphael Mabo, Mar 22, 2011

Raphael Mabo wrote:

Fogel70 wrote:

Hyper-P is great, but it would be even better if program-line was supported when > changing aperture or shutter speed, but as it is now it will go back to "normal" > program-line when setting is manually changed.

No, no program line is used when you set aperture or shutter.

Yes, but the automatic exposure in Av and Tv is weighted the same as if using normal program line. So normal program line is IMO the only one that works well in Hyper-P as exposure is weighed the same even when changing aperture, shutter speed or ISO.

This is because that when you set aperture - the camera sets the shutter after the light conditions, and when you set the shutter - the camera sets the aperture after the light conditions.

Auto-ISO can do the same.

FI if using "sports" PL in Hyper-P the camera will choose shutter speed of maybe > 1/500s or faster, but if changing aperture the camera go back using "normal" PL > where shutter speed is set by focal length and you often end up with much slower > shutter speed.

But that is because your choosen aperture is too small for the current light conditions. If you open up the aperture, the shutter speed will be faster.

That is not true, the sport PL is programmed to set a fast shutter speed and auto-ISO will then choose higher ISO, where "normal" weighted exposure will choose shutter speed connected to focal length which usually means slower shutter speed and lower ISO than with sports PL.

If the camera would choose a fast shutter speed with a small aperture here then the image would be underexposed.

Not as long as auto-ISO can set ISO for correct exposure.

When you open up aperture - shutter speed gets faster.
When you close down aperture - shutter speed gets slower.
When you set a faster shutter speed - aperture opens up.
When you set a slower shutter speed - aperture closes down.

Not necessarily, when using auto-ISO the camera might choose to change ISO instead of aperture or shutter speed.

This is to retain the same exposure value.

So say that you have light conditions that says

aperture f/2.8 and shutter 1/500 for good exposure, then f/4 with 1/250 and f/2 with 1/1000 gives same exposure as f/2.8 and 1/500.

If using sports program line in Hyper-P that choose 1/500s f/2.8 and ISO 1600, and aperture is changed to f/4 the camera might change shutter speed to say 1/60s and ISO to 400. So if sports PL is chosen for fast shutter speeds in Hyper-P there is usually not possible to stop down aperture and still get the same fast shutter speed.

But if using Program-mode with P-shift it is possible as the program-line is kept when shifting exposure.

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