Luminous Landscape Forum
Equipment & Techniques => Digital Cameras & Shooting Techniques => Topic started by: dreed on May 29, 2008, 11:32:00 am
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Recently, I've been doing more shooting with the "expose to the right" theme in order to push the photos I'm capturing from being nearly all in the middle of the histogram to being very close to the right.
This, however, presents a couple of problems:
1) reviewing on the back of the camera (20D) only shows the over exposed image;
2) when shooting raw+jpeg, the jpegs are also over exposed;
3) when reviewing photos on a computer, they always need to be adjusted before making any subjective decisions about said photos.
With Canon's DPP, if I select all of the raw images and get it to recalculate the tone curve, it is a step in the right direction for reviewing. But DPP isn't that great. Are there any other techniques (using Lightroom or ACR) that can be used to generate thumbnails that are correctly exposed?
This also leads to some feature suggestions for camera makers in the form of custom settings to tweak:
* when shooting RAW+JPEG, be able to control the JPEG exposure independant from RAW:
0 = the same as RAW
1 = correct the JPEG exposure to be zero
* be able to control the exposure of the thumbnail stored in the RAW file:
0 = the same as RAW
1 = correct the thumbnail exposure to be zero
* when displaying the image for review, be able to control which image you see:
0 = the same as RAW
1 = corrected for exposure being zero
2 = two images displayed, one is the same as RAW, the other is corrected for zero, with blown highlights and histogram being displayed for both (a method to select the correct one and "zoom" on that is also required.)
I'm not sure how this would work for tools such as ACR/DPP, but my desire is this: after taking the photo, I want to know two things:
1) are any highlights blown
2) what the captured scene looks like when correctly exposed.
Shooting three photos, 0,+1/2,+1 or similar, is a very crude answer to this problem and reduces the effective capacity of the digital storage medium. i.e. I'm aware of this as a potential answer but I don't believe that this is either the intent of it nor that it is an effective answer.
I would be happy to sacrifice half of my fps for the above features (I understand that they would require extra CPU time to compute on the camera.)
There is one last item I'd like to put on my digital camera software wishlist:
* be able to put the camera in a mode where you say "I want the camera to keep taking photos until it has taken one with the settings required to get maximum exposure, without blowing any highlights and to store that picture." If my camera is mounted on a tripod, I figure I should be able to ask it to take the best picture of a scene, that it can, without me having to fiddle with buttons and dials. Afterall, deciding whether or not there are blown highlights and moving the exposure compensation to get the histogram more to the right should be an easy task for a camera sized computer Getting a picture "as far to the right as possible" shouldn't require doing -1/0/+1, etc.
Having said all that, does anyone know if any cameras (or camera companies) are doing anything in this area?
Cheers,
Darren
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3) when reviewing photos on a computer, they always need to be adjusted before making any subjective decisions about said photos.
With Canon's DPP, if I select all of the raw images and get it to recalculate the tone curve, it is a step in the right direction for reviewing. But DPP isn't that great. Are there any other techniques (using Lightroom or ACR) that can be used to generate thumbnails that are correctly exposed?
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A few thoughts :
- No automatic program will ever get you the perfect tonality as it is a highly subjective process,
- that said, I agree ETTR may complicate the first thumbnail viewing : you could try LR2's AutoTone (LR1's one has a definite tendancy to overexpose for me),
- in any case, do NOT attempt to judge tonality and color on the camera screen! The only useful information imho comes from the histogram of the ETTR'd file (yes, it would be nice to have a raw histogram).
My conclusion : no need for a jpeg.
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Using the histogram obviously presents the issue that it is based on a jpeg vs a RAW expsoure which has more headroom. Trying to get ETTR using the histo also takes time chimping and also creates a lot of movement/noise that could disturb some subjects (read critters).
Pick up a cheap (Sekonic 358) incident meter. Best $200 you'll spend on gear (and I've spent a lot). If I'm on say a soccer field, or out for a winter hike, etc., I take a quick reading and away I go.
As light changes, I'll either take a reading or just adjust aperture, etc to compensate. The trick with the meter is it gives you the perfect baseline, quickly to start with.
It also handy for deciding if a new lens will do what I want in certain venues. Prior to purchase. I just take a meter reading where I normally expect to use said glass,and play with the aperture/ISO It will tell you prettu quickly, if you know your camera's ISO performance, if that new spendy lens will be fast enough to give you the IQ you want..
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A few thoughts :
- No automatic program will ever get you the perfect tonality as it is a highly subjective process,
- that said, I agree ETTR may complicate the first thumbnail viewing : you could try LR2's AutoTone (LR1's one has a definite tendancy to overexpose for me),
- in any case, do NOT attempt to judge tonality and color on the camera screen! The only useful information imho comes from the histogram of the ETTR'd file (yes, it would be nice to have a raw histogram).
My conclusion : no need for a jpeg.
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I use the JPEG for another purpose - instant B&W copy of the photo.
With DPP I reset the "mode" of all the CR2's back to "standard", so they show up as colour thumbnails and of course all of the colour channels are already there.
At the expense of some disk space, this gives me an instant notion of whether a photo works as B&W or not. While the out-of-camera JPEG in B&W is still likely to require improving to get the best out of the picture, I find it easier than trying to setup an import/batch process.
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Just a casual observation: Three out of four people start to over-expose their digital captures after having been told about ETTR.
-- Olaf
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Just a casual observation: Three out of four people start to over-expose their digital captures after having been told about ETTR.
-- Olaf
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Yes. Here's how I'd like a camera to work. You set it for spot meter mode, and depress the exposure lock button when the meter spot is on top of an object you think is about a middle tone. Then you point the meter spot at any other object, and the ribbon bar at the bottom of the frame tells you what the object which is now under the spot would be exposed relative to that, i.e. how many stops over or under. And then you adjust the exposure compensation wheel to get everything where you want it.
So let's say you initially press the exposure lock button when the spot is on some grass. Then you place the spot meter on someone's skin and find that it's one stop higher. Great. Next you check their white shirt and see that would be 6 stops higher. Too high, so you turn the exposure wheel back a stop or two, and recheck all of your importat subject tones. Once you're satisfied everything will be as ETTR as you want, press the shutter.
Or better yet, find a way to overlay the projected image in the finder with blinking highlight indicators like you get on the LCD panel. Shouldn't be too difficult to add an additional layer of transparent LCD between the mirror and the finder somewhere, and a lot of high end SLRs already have meter spots throughout most of the frame. It would be especially useful if you could set the range between mid tone and highlight cutoff yourself. So maybe after testing, you decide you're comfortable with 5 stops above middle gray before you want to see a warning blink. Maybe I'm more conservative, and want to see the blink at 4.5 stops. I'd want a low-exposure noise warning as well.
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Yes. Here's how I'd like a camera to work. You set it for spot meter mode, and depress the exposure lock button when the meter spot is on top of an object you think is about a middle tone. Then you point the meter spot at any other object, and the ribbon bar at the bottom of the frame tells you what the object which is now under the spot would be exposed relative to that, i.e. how many stops over or under. And then you adjust the exposure compensation wheel to get everything where you want it.
So let's say you initially press the exposure lock button when the spot is on some grass. Then you place the spot meter on someone's skin and find that it's one stop higher. Great. Next you check their white shirt and see that would be 6 stops higher. Too high, so you turn the exposure wheel back a stop or two, and recheck all of your importat subject tones. Once you're satisfied everything will be as ETTR as you want, press the shutter.
Or better yet, find a way to overlay the projected image in the finder with blinking highlight indicators like you get on the LCD panel. Shouldn't be too difficult to add an additional layer of transparent LCD between the mirror and the finder somewhere, and a lot of high end SLRs already have meter spots throughout most of the frame. It would be especially useful if you could set the range between mid tone and highlight cutoff yourself. So maybe after testing, you decide you're comfortable with 5 stops above middle gray before you want to see a warning blink. Maybe I'm more conservative, and want to see the blink at 4.5 stops. I'd want a low-exposure noise warning as well.
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I want one of those cameras too!
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Somewhat off topic but I found this explanation interesting:
"A common maxim in digital photography is that image quality is maximized by "exposing to the right" (ETTR) -- that is, raising the exposure as much as possible without clipping highlights. It is often stated that in doing so, one makes the best use of the "number of available levels" in the raw data. This explication for instance can be found in a much-quoted tutorial on Luminous-Landscape.com. The thinking is that, because raw is a linear capture medium, each higher stop in exposure accesses the next higher bit in the digital data, and twice as many raw levels are used in encoding the raw capture. For instance, in a 12-bit file, the highest stop of exposure has 2048 levels, the next highest stop 1024 levels, the one below that 512 levels, and so on. Naively it would seem obvious that the highest quality image data would arise from concentrating the image histogram in the higher exposure zones, where the abundance of levels allows finer tonal transitions.
However, the issue is not the number of raw levels in any given segment of the raw data (as measured e.g. in stops down from raw saturation point). Rather, the point is that by exposing to the right, one achieves a higher signal to noise ratio in the raw data. The number of available raw levels has little to do with the proper reason to expose right, since as we have seen the noise rises with signal and in fact the many raw levels available in higher exposure zones are largely wasted in digitizing photon shot noise (there will be more to say about this in a moment, when we consider NEF compression)."
http://theory.uchicago.edu/~ejm/pix/20d/te...se-p3.html#ETTR (http://theory.uchicago.edu/~ejm/pix/20d/tests/noise/noise-p3.html#ETTR)
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I want one of those cameras too!
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I think one of the later Hasselblad V series prisms worked in a similar fashion, but I'm not sure. Since I tended to shoot Hasselblads from a tripod anyway, it would have been a pain for me to check all of the important tone areas with one. So I never really looked into it. Instead, I just used ye olde Pentax spot meter.
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I think one of the later Hasselblad V series prisms worked in a similar fashion, but I'm not sure. Since I tended to shoot Hasselblads from a tripod anyway, it would have been a pain for me to check all of the important tone areas with one. So I never really looked into it. Instead, I just used ye olde Pentax spot meter.
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I have the PME-45 prism on my 503CWD. It has simple but very accurate TTL metering. The variables are max f stop, ISO and three types of metering. The exposire reading is given in EV.
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So let's say you initially press the exposure lock button when the spot is on some grass. Then you place the spot meter on someone's skin and find that it's one stop higher. Great. Next you check their white shirt and see that would be 6 stops higher. Too high, so you turn the exposure wheel back a stop or two, and recheck all of your importat subject tones. Once you're satisfied everything will be as ETTR as you want, press the shutter.
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I don't know about other brands, but you can do this with Nikon cameras if you take your camera out of programmed exposure mode.
1. Put camera in Manual Exposure mode with spot-meter
2. Point spot-meter at midtone
3. Dial in exposure that registers 'correct' on the exposure meter (ie centered over 0EV on the scale).
4. Point the spot meter at something else and it will show you how many stops over/under it is relative to the current exposure setting (which is your midtone).
The only limitation to this is in the # of stops displayed in the exposure meter, I think it's +/- 3 stops unlessyou have camera configured for 1/2 stop increments.
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Recently, I've been doing more shooting with the "expose to the right" theme in order to push the photos I'm capturing from being nearly all in the middle of the histogram to being very close to the right.
This, however, presents a couple of problems:
1) reviewing on the back of the camera (20D) only shows the over exposed image;
2) when shooting raw+jpeg, the jpegs are also over exposed;
3) when reviewing photos on a computer, they always need to be adjusted before making any subjective decisions about said photos.
[a href=\"index.php?act=findpost&pid=198757\"][{POST_SNAPBACK}][/a]
That last one (3) is easy...
Use ACR /LR and make a new default that adjusts the tones back to where the image is visually OK. You'll probably find that using ETTR you will generally make similar adjustments to get the image back to where it looks best - save these adjustments as a new default and the images will open with the correction already made.
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Yes. Here's how I'd like a camera to work. You set it for spot meter mode, and depress the exposure lock button when the meter spot is on top of an object you think is about a middle tone. Then you point the meter spot at any other object, and the ribbon bar at the bottom of the frame tells you what the object which is now under the spot would be exposed relative to that, i.e. how many stops over or under. And then you adjust the exposure compensation wheel to get everything where you want it.
So let's say you initially press the exposure lock button when the spot is on some grass. Then you place the spot meter on someone's skin and find that it's one stop higher. Great. Next you check their white shirt and see that would be 6 stops higher. Too high, so you turn the exposure wheel back a stop or two, and recheck all of your importat subject tones. Once you're satisfied everything will be as ETTR as you want, press the shutter.
This is available in the 1DS-Mark III, however it only gives you about +/- 2.5 Stops.
1. Set camera to AV and Spot Metering Mode
2. Find an object that you want to meter off, focus as normal, and then press the FEL buttom. This locks that exposure reading and an indicator mark locks in the center of the display on the RIGHT side of viewfinder.
Now, when you move around to meter other objects, there is a sliding marker that moves up and down, +/- 2.5 Stops from the first reading, indicating its releative exposure.
3. If you then press FEL again, on different object, it locks in that one as well, and shifts the camera exposure to be correct for those 'two' objects, (They are balanced normally, on the display). The sliding meter keeps working showing you relative exposure for other objects you point at.
4. You can still use the standard +/- exposure compensation scale to move the exposure around as normal.
Works very much like my Sekonic 758DR in the multi-reading average mode, except not quite as wide in the stop range. Dosn't seem to work in full Manual though, which is a bit annoying.
Edit: Its called "Multi Spot Metering, page 91 of Canon Manual"
Can do up to 8 readings.
Mark.
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This is available in the 1DS-Mark III, however it only gives you about +/- 2.5 Stops.
1. Set camera to AV and Spot Metering Mode
2. Find an object that you want to meter off, focus as normal, and then press the FEL buttom. This locks that exposure reading and an indicator mark locks in the center of the display on the RIGHT side of viewfinder.
Now, when you move around to meter other objects, there is a sliding marker that moves up and down, +/- 2.5 Stops from the first reading, indicating its releative exposure.
3. If you then press FEL again, on different object, it locks in that one as well, and shifts the camera exposure to be correct for those 'two' objects, (They are balanced normally, on the display). The sliding meter keeps working showing you relative exposure for other objects you point at.
4. You can still use the standard +/- exposure compensation scale to move the exposure around as normal.
Works very much like my Sekonic 758DR in the multi-reading average mode, except not quite as wide in the stop range. Dosn't seem to work in full Manual though, which is a bit annoying.
Edit: Its called "Multi Spot Metering, page 91 of Canon Manual"
Can do up to 8 readings.
Mark.
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2.5 stops doesn't cut it for me. I'd like to see a display that covers the whole dynamic range of the sensor. Canon has been using the same +/- 2.5 stops range for exposure compensation since at least 1994, and I'm starting to find it increasingly restrictive. It's a real pain for shooting the exposures needed for an HDR image. I'd really like to be able to rattle off a +/- 4 EV set for that, but no joy with my Canons at the moment.