Exposure compensation in P67ii

Jerry_K · 04-06-2010, 04:18 PM

Hi folks,

I just got a roll of Velvia developed on which a shoot a landscape with the intention of turning some frames into a HDR image and have some fun with tone mapping and such. To that end I took three exposures in manual metering mode with 0, +2 EV and -2 EV exposure compensation settings. Shutter speed and aperture were fixed. Yet all three frames came out identical. The user manual seems to suggest that exposure compensation dial works the same in manual and aperture priority metering mode. I found however an article on luminous-landscape.com that suggests this is not he case and exposure compensation works only in aperture priority.
So, how does it really work? Could it be that something is broken in the camera? Or do I do something wrong?

Jerry.

Smolk · 04-06-2010, 04:33 PM

I do not have the 67ii (which seems wonderful to me!), but compensation works on the meter - i.e., in manual mode, it has no effect on exposure if you compensate. However, it would have effect on a TTL Pentax flash and can therefore be handy in fill-in flash situations.

In automatic mode, whatever priority, the compensation should have the effect you expected.

tuco · 04-06-2010, 05:10 PM

I don't have the 67ii either but think about it. If the shutter and aperture are fixed in manual mode, how would you get a different exposure on the next shot? The camera needs to control something be it shutter or aperture to get your +/-EV.

I suspect in the EV mode the light meter needle moved and you were suppose to adjust either shutter or aperture to bring it back to the middle. So in that sense, yes, EV comp works in manual mode except it doesn't do the physical changes to the camera - you do based on the meter reading.

Jerry_K · 04-06-2010, 05:25 PM

Originally posted by tuco

I don't have the 67ii either but think about it. If the shutter and apeture are fixed in manual mode, how would you get a different exposure on the next shot? The camera needs to control something be it shutter or aperture to get your +/-EV.

Of course. In manual mode I would expect the camera to vary the shutter speed from the reference value set on the speed dial. Like it does in aperture priority mode. The difference being: the reference shutter speed in AP mode is determined by the meter, while in manual mode it is determined by the user. Otherwise it's impossible to adjust (compensate) exposure by values smaller than 1 EV at any given aperture. For instance, on a shutter speed dial I can set the speed to either 1/500 sec or 1/1000 sec (which is a difference of one stop) but not to anything in between. I would also expect that my manually set combination of aperture and shutter speed defines a reference exposure from which I could deviate (in units of EV) by up to +/- 3 EV, but WITHOUT changing the reference.

Therefore, my question could be reformulated in the following manner: how do I do bracketing in manual metering mode by values being fractions of one step?

Jerry.

bensonga · 04-06-2010, 05:29 PM

I have the 67II and the manual addresses this on page 56. It is indeed possible to use exposure compensation in "metered manual mode", but the instructions sure aren't very clear about it. It looks like in Exp Comp mode the +/- compensation value you've set will show up as a single vertical bar above the bar graph (instead of the usual over/under exposure graph) +/- 1-3 EVs and that you have to then adjust the aperture ring or shutter speed dial to place this single vertical bar in the center, which will then give you the correct exposure compensation. Not at all intuitive, for sure! I'll give it a try with a roll of film I've got in the camera and see if it works.

Gary

tuco · 04-06-2010, 05:34 PM

Originally posted by Jerry_K

Therefore, my question could be reformulated in the following manner: how do I do bracketing in manual metering mode by values being fractions of one step?

Jerry.

If I understand you correctly, you want to make an exposure change that is not a whole stop increment? Well, you can do 1/2 stop aperture increments on most if not all 67 lenses. For a given shutter/aperture on one shot, you can adjust 1/2 stop by changing the aperture and similarly 1.5 stop adjustment by changing both shutter and aperture (or aperture alone), for example.

Jerry_K · 04-06-2010, 05:46 PM

Originally posted by bensonga

I have the 67II and the manual addresses this on page 56. It is indeed possible to use exposure compensation in "metered manual mode", but the instructions sure aren't very clear about it. It looks like in Exp Comp mode the +/- compensation value you've set will show up as a single vertical bar above the bar graph (instead of the usual over/under exposure graph) +/- 1-3 EVs and that you have to then adjust the aperture ring or shutter speed dial to place this single vertical bar in the center, which will then give you the correct exposure compensation. Not at all intuitive, for sure! I'll give it a try with a roll of film I've got in the camera and see if it works.

Gary, what you've said makes perfect sense! Now it explaines why I had to turn the dial the "wrong" way in order to bring the bar to the middle. For instance, the meter says the scene would be underexposed at given shutter/aperture setting, which I would intuitively try to counter by adjusting Exp Comp dial to the + side. Not so, however. I have to turn it to minus side to bring the bar to the middle but all that accomplishes is that the Exp Comp dial barely shows me a measurment of how much I'm off of proper exposure.

Jerry.

Wheatfield · 04-06-2010, 05:49 PM

Originally posted by Jerry_K

Of course. In manual mode I would expect the camera to vary the shutter speed from the reference value set on the speed dial. Like it does in aperture priority mode. The difference being: the reference shutter speed in AP mode is determined by the meter, while in manual mode it is determined by the user. Otherwise it's impossible to adjust (compensate) exposure by values smaller than 1 EV at any given aperture. For instance, on a shutter speed dial I can set the speed to either 1/500 sec or 1/1000 sec (which is a difference of one stop) but not to anything in between. I would also expect that my manually set combination of aperture and shutter speed defines a reference exposure from which I could deviate (in units of EV) by up to +/- 3 EV, but WITHOUT changing the reference.

Therefore, my question could be reformulated in the following manner: how do I do bracketing in manual metering mode by values being fractions of one step?

Jerry.

If you are in manual, then all the light meter is doing is giving you a reference regarding what it thinks the exposure should be.
Manual exposure means that the photographer inputs both aperture and shutter speed.
If you want to do bracketed exposures with the intent of blending them, then you want a fixed aperture and variable shutter speed, since you don't want DOF changes playing havoc with your image.
So, in manual, you can change the shutter speed, though with the 67II I suspect you are stuck with full stop increments.
Or, you can set the camera to aperture preferred AE (I believe this is the 67II's auto exposure method) and use the exposure comp to vary the shutter speed in whatever increments it is calibrated in.

Jerry_K · 04-06-2010, 06:01 PM

Originally posted by tuco

If I understand you correctly, you want to make an exposure change that is not a whole stop increment? Well, you can do 1/2 stop aperture increments on most if not all 67 lenses. For a given shutter/aperture on one shot, you can adjust 1/2 stop by changing the aperture and similarly 1.5 stop adjustment by changing both shutter and aperture (or aperture alone), for example.

To be precise, what I want to accomplish is bracketing, that is to make identical photographs (in terms of the content to the last detail) differing only in the luminance received. Changing the aperture changes the content - the photographs won't be identical due to differences in the image caused by different depths of field. This is crucial for stacking frames for tone mapping or stitching frames to make panoramas.

From what you guys are saying it seems the only way to do it is to use the AP mode, however in that case I can't decide the initial (reference) exposure level; the meter will do it for me. And it will change it if conditions change from one shot to the next. Otherwise I have to use full stop only increments on the shutter speed dial (provided I'm not starting from 4 sec or 1/1000 sec extremes).

Jerry.

bensonga · 04-06-2010, 07:59 PM

Here's what I would do....if I wanted to stay in metered manual mode, record one exposure at the indicated "correct" exposure and then bracket +/- 1, 2 or 3 stops (whatever you want).

I wouldn't bother with the exposure compensation dial. I'd just take the first exposure as indicated and then change either my aperture or shutter speed dial +/- 1, 2 or 3 stops. In metered manual mode, I just don't see the benefit of using the exposure compensation dial at all (if I understand it correctly)...seems like it is really only useful in aperture or shutter priority modes.

But, I could be wrong...wouldn't be the first time!

Gary

tuco · 04-06-2010, 08:04 PM - **1 Like**

The next question is why do you want to blend pictures anyway. You get really good range with film and you'll most likely end up creating a fantasy picture. Overdone HDR is one of those stages beginners goes through after they have advanced past the supersaturation phase and then they move on (the crazy angle phase). You can just skip that step in your photographic development.

Wheatfield · 04-06-2010, 08:19 PM

I like candy cane HDR...

ARCASIA · 04-07-2010, 02:46 AM

Hi Gary,

I think he is looking for more refinement in exposure setting than the full stops offered by the shutter speed adjustment, and thought he could get it from the exposure compensation adjustment (1/3 stops). Anyways, what he wants to do can't be done in metered manual mode on the 67II - his only option is full stop adjustment.

Best, Alan

Originally posted by bensonga

Here's what I would do....if I wanted to stay in metered manual mode, record one exposure at the indicated "correct" exposure and then bracket +/- 1, 2 or 3 stops (whatever you want).

I wouldn't bother with the exposure compensation dial. I'd just take the first exposure as indicated and then change either my aperture or shutter speed dial +/- 1, 2 or 3 stops. In metered manual mode, I just don't see the benefit of using the exposure compensation dial at all (if I understand it correctly)...seems like it is really only useful in aperture or shutter priority modes.

But, I could be wrong...wouldn't be the first time!

Gary

Wheatfield · 04-07-2010, 06:08 AM

Originally posted by Jerry_K

From what you guys are saying it seems the only way to do it is to use the AP mode, however in that case I can't decide the initial (reference) exposure level; the meter will do it for me. And it will change it if conditions change from one shot to the next. Otherwise I have to use full stop only increments on the shutter speed dial (provided I'm not starting from 4 sec or 1/1000 sec extremes).

Jerry.

You need to think outside the box.
In auto, use the ISO control to bias the exposure away from what the meter thinks it wants, and then use exposure compensation to do your bracketing.

Jerry_K · 04-07-2010, 12:10 PM

Originally posted by tuco

The next question is why do you want to blend pictures anyway. You get really good range with film and you'll most likely end up creating a fantasy picture. Overdone HDR is one of those stages beginners goes through after they have advanced past the supersaturation phase and then they move on (the crazy angle phase). You can just skip that step in your photographic development.

I want to do it just for the heck of it, out of shameless curiosity and to learn it. And also to play with Hugin software on Linux to see what it's worth. That's pretty much all my motivation

.

However I have to strongly object against bias toward "fantasy" pictures as somewhat illegitimate form of artistic expression. I do a lot of B&W photography and what is it if not a mere "fantasy"? After all, it can look realistic only to a dog. Even using some filters could be classified as making fantasy pictures. Same could be said about using Velvia instead of Provia or shooting a scene on an infrared film. I agree though that overdoing it may look nasty, but overdoing it is not my intention nor a stop along the path of my photographic development :-).
On the other hand HDR is the only way to squeeze biological eye's dynamic range into screen's or paper's dynamic range while preserving local contrast.

J.

04-06-2010, 04:18 PM	#1
Jerry_K New Member Join Date: Mar 2010 Location: San Diego, CA Posts: 14	Exposure compensation in P67ii Hi folks, I just got a roll of Velvia developed on which a shoot a landscape with the intention of turning some frames into a HDR image and have some fun with tone mapping and such. To that end I took three exposures in manual metering mode with 0, +2 EV and -2 EV exposure compensation settings. Shutter speed and aperture were fixed. Yet all three frames came out identical. The user manual seems to suggest that exposure compensation dial works the same in manual and aperture priority metering mode. I found however an article on luminous-landscape.com that suggests this is not he case and exposure compensation works only in aperture priority. So, how does it really work? Could it be that something is broken in the camera? Or do I do something wrong? Jerry.

04-06-2010, 05:10 PM	#3
tuco Pentaxian Join Date: Jul 2009 Location: Pugetopolis Posts: 11,026	I don't have the 67ii either but think about it. If the shutter and aperture are fixed in manual mode, how would you get a different exposure on the next shot? The camera needs to control something be it shutter or aperture to get your +/-EV. I suspect in the EV mode the light meter needle moved and you were suppose to adjust either shutter or aperture to bring it back to the middle. So in that sense, yes, EV comp works in manual mode except it doesn't do the physical changes to the camera - you do based on the meter reading. Last edited by tuco; 04-06-2010 at 05:23 PM.

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04-06-2010, 04:33 PM	#2
Smolk Pentaxian Join Date: Feb 2010 Location: Eerbeek Photos: Gallery \| Albums Posts: 1,857	I do not have the 67ii (which seems wonderful to me!), but compensation works on the meter - i.e., in manual mode, it has no effect on exposure if you compensate. However, it would have effect on a TTL Pentax flash and can therefore be handy in fill-in flash situations. In automatic mode, whatever priority, the compensation should have the effect you expected.

04-06-2010, 05:25 PM	#4
Jerry_K New Member Join Date: Mar 2010 Location: San Diego, CA Posts: 14 Original Poster	Originally posted by tuco I don't have the 67ii either but think about it. If the shutter and apeture are fixed in manual mode, how would you get a different exposure on the next shot? The camera needs to control something be it shutter or aperture to get your +/-EV. Of course. In manual mode I would expect the camera to vary the shutter speed from the reference value set on the speed dial. Like it does in aperture priority mode. The difference being: the reference shutter speed in AP mode is determined by the meter, while in manual mode it is determined by the user. Otherwise it's impossible to adjust (compensate) exposure by values smaller than 1 EV at any given aperture. For instance, on a shutter speed dial I can set the speed to either 1/500 sec or 1/1000 sec (which is a difference of one stop) but not to anything in between. I would also expect that my manually set combination of aperture and shutter speed defines a reference exposure from which I could deviate (in units of EV) by up to +/- 3 EV, but WITHOUT changing the reference. Therefore, my question could be reformulated in the following manner: how do I do bracketing in manual metering mode by values being fractions of one step? Jerry.

04-06-2010, 05:29 PM	#5
bensonga Senior Member Join Date: Mar 2010 Location: Alaska Photos: Albums Posts: 149	I have the 67II and the manual addresses this on page 56. It is indeed possible to use exposure compensation in "metered manual mode", but the instructions sure aren't very clear about it. It looks like in Exp Comp mode the +/- compensation value you've set will show up as a single vertical bar above the bar graph (instead of the usual over/under exposure graph) +/- 1-3 EVs and that you have to then adjust the aperture ring or shutter speed dial to place this single vertical bar in the center, which will then give you the correct exposure compensation. Not at all intuitive, for sure! I'll give it a try with a roll of film I've got in the camera and see if it works. Gary

04-06-2010, 05:34 PM	#6
tuco Pentaxian Join Date: Jul 2009 Location: Pugetopolis Posts: 11,026	Originally posted by Jerry_K Therefore, my question could be reformulated in the following manner: how do I do bracketing in manual metering mode by values being fractions of one step? Jerry. If I understand you correctly, you want to make an exposure change that is not a whole stop increment? Well, you can do 1/2 stop aperture increments on most if not all 67 lenses. For a given shutter/aperture on one shot, you can adjust 1/2 stop by changing the aperture and similarly 1.5 stop adjustment by changing both shutter and aperture (or aperture alone), for example.

04-06-2010, 05:46 PM	#7
Jerry_K New Member Join Date: Mar 2010 Location: San Diego, CA Posts: 14 Original Poster	Originally posted by bensonga I have the 67II and the manual addresses this on page 56. It is indeed possible to use exposure compensation in "metered manual mode", but the instructions sure aren't very clear about it. It looks like in Exp Comp mode the +/- compensation value you've set will show up as a single vertical bar above the bar graph (instead of the usual over/under exposure graph) +/- 1-3 EVs and that you have to then adjust the aperture ring or shutter speed dial to place this single vertical bar in the center, which will then give you the correct exposure compensation. Not at all intuitive, for sure! I'll give it a try with a roll of film I've got in the camera and see if it works. Gary, what you've said makes perfect sense! Now it explaines why I had to turn the dial the "wrong" way in order to bring the bar to the middle. For instance, the meter says the scene would be underexposed at given shutter/aperture setting, which I would intuitively try to counter by adjusting Exp Comp dial to the + side. Not so, however. I have to turn it to minus side to bring the bar to the middle but all that accomplishes is that the Exp Comp dial barely shows me a measurment of how much I'm off of proper exposure. Jerry.

04-06-2010, 05:49 PM	#8
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,981	Originally posted by Jerry_K Of course. In manual mode I would expect the camera to vary the shutter speed from the reference value set on the speed dial. Like it does in aperture priority mode. The difference being: the reference shutter speed in AP mode is determined by the meter, while in manual mode it is determined by the user. Otherwise it's impossible to adjust (compensate) exposure by values smaller than 1 EV at any given aperture. For instance, on a shutter speed dial I can set the speed to either 1/500 sec or 1/1000 sec (which is a difference of one stop) but not to anything in between. I would also expect that my manually set combination of aperture and shutter speed defines a reference exposure from which I could deviate (in units of EV) by up to +/- 3 EV, but WITHOUT changing the reference. Therefore, my question could be reformulated in the following manner: how do I do bracketing in manual metering mode by values being fractions of one step? Jerry. If you are in manual, then all the light meter is doing is giving you a reference regarding what it thinks the exposure should be. Manual exposure means that the photographer inputs both aperture and shutter speed. If you want to do bracketed exposures with the intent of blending them, then you want a fixed aperture and variable shutter speed, since you don't want DOF changes playing havoc with your image. So, in manual, you can change the shutter speed, though with the 67II I suspect you are stuck with full stop increments. Or, you can set the camera to aperture preferred AE (I believe this is the 67II's auto exposure method) and use the exposure comp to vary the shutter speed in whatever increments it is calibrated in.

04-06-2010, 06:01 PM	#9
Jerry_K New Member Join Date: Mar 2010 Location: San Diego, CA Posts: 14 Original Poster	Originally posted by tuco If I understand you correctly, you want to make an exposure change that is not a whole stop increment? Well, you can do 1/2 stop aperture increments on most if not all 67 lenses. For a given shutter/aperture on one shot, you can adjust 1/2 stop by changing the aperture and similarly 1.5 stop adjustment by changing both shutter and aperture (or aperture alone), for example. To be precise, what I want to accomplish is bracketing, that is to make identical photographs (in terms of the content to the last detail) differing only in the luminance received. Changing the aperture changes the content - the photographs won't be identical due to differences in the image caused by different depths of field. This is crucial for stacking frames for tone mapping or stitching frames to make panoramas. From what you guys are saying it seems the only way to do it is to use the AP mode, however in that case I can't decide the initial (reference) exposure level; the meter will do it for me. And it will change it if conditions change from one shot to the next. Otherwise I have to use full stop only increments on the shutter speed dial (provided I'm not starting from 4 sec or 1/1000 sec extremes). Jerry.

04-06-2010, 07:59 PM	#10
bensonga Senior Member Join Date: Mar 2010 Location: Alaska Photos: Albums Posts: 149	Here's what I would do....if I wanted to stay in metered manual mode, record one exposure at the indicated "correct" exposure and then bracket +/- 1, 2 or 3 stops (whatever you want). I wouldn't bother with the exposure compensation dial. I'd just take the first exposure as indicated and then change either my aperture or shutter speed dial +/- 1, 2 or 3 stops. In metered manual mode, I just don't see the benefit of using the exposure compensation dial at all (if I understand it correctly)...seems like it is really only useful in aperture or shutter priority modes. But, I could be wrong...wouldn't be the first time! Gary

04-06-2010, 08:04 PM - 1 Like	#11
tuco Pentaxian Join Date: Jul 2009 Location: Pugetopolis Posts: 11,026	The next question is why do you want to blend pictures anyway. You get really good range with film and you'll most likely end up creating a fantasy picture. Overdone HDR is one of those stages beginners goes through after they have advanced past the supersaturation phase and then they move on (the crazy angle phase). You can just skip that step in your photographic development.

04-06-2010, 08:19 PM	#12
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,981	I like candy cane HDR...

04-07-2010, 02:46 AM	#13
ARCASIA Forum Member Join Date: Jun 2009 Location: Baguio, Benguet Posts: 91	Hi Gary, I think he is looking for more refinement in exposure setting than the full stops offered by the shutter speed adjustment, and thought he could get it from the exposure compensation adjustment (1/3 stops). Anyways, what he wants to do can't be done in metered manual mode on the 67II - his only option is full stop adjustment. Best, Alan Originally posted by bensonga Here's what I would do....if I wanted to stay in metered manual mode, record one exposure at the indicated "correct" exposure and then bracket +/- 1, 2 or 3 stops (whatever you want). I wouldn't bother with the exposure compensation dial. I'd just take the first exposure as indicated and then change either my aperture or shutter speed dial +/- 1, 2 or 3 stops. In metered manual mode, I just don't see the benefit of using the exposure compensation dial at all (if I understand it correctly)...seems like it is really only useful in aperture or shutter priority modes. But, I could be wrong...wouldn't be the first time! Gary

04-07-2010, 06:08 AM	#14
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,981	Originally posted by Jerry_K From what you guys are saying it seems the only way to do it is to use the AP mode, however in that case I can't decide the initial (reference) exposure level; the meter will do it for me. And it will change it if conditions change from one shot to the next. Otherwise I have to use full stop only increments on the shutter speed dial (provided I'm not starting from 4 sec or 1/1000 sec extremes). Jerry. You need to think outside the box. In auto, use the ISO control to bias the exposure away from what the meter thinks it wants, and then use exposure compensation to do your bracketing.

04-07-2010, 12:10 PM	#15
Jerry_K New Member Join Date: Mar 2010 Location: San Diego, CA Posts: 14 Original Poster	Originally posted by tuco The next question is why do you want to blend pictures anyway. You get really good range with film and you'll most likely end up creating a fantasy picture. Overdone HDR is one of those stages beginners goes through after they have advanced past the supersaturation phase and then they move on (the crazy angle phase). You can just skip that step in your photographic development. I want to do it just for the heck of it, out of shameless curiosity and to learn it. And also to play with Hugin software on Linux to see what it's worth. That's pretty much all my motivation . However I have to strongly object against bias toward "fantasy" pictures as somewhat illegitimate form of artistic expression. I do a lot of B&W photography and what is it if not a mere "fantasy"? After all, it can look realistic only to a dog. Even using some filters could be classified as making fantasy pictures. Same could be said about using Velvia instead of Provia or shooting a scene on an infrared film. I agree though that overdoing it may look nasty, but overdoing it is not my intention nor a stop along the path of my photographic development :-). On the other hand HDR is the only way to squeeze biological eye's dynamic range into screen's or paper's dynamic range while preserving local contrast. J.