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09-06-2013, 10:44 PM   #16
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I think it is totally possible and makes sense for very specific applications. Think of the Matrix metering. It has 77 segments which are measured individually and then compared with a database to determinate best Av and Tv values. Now, for a very simple "ETTR routine" that attemps to save all the data, it could be something like:
- Read all 77 segments and find the brightest one.
- set Av and Tv for the brightest segment, overexposing 2 stops (or whatever is the threshold is for a specific sensor)

There could even be a new database made with ETTR into account so that you can broaden the cases where it works (If you do want to clip some areas for example)

09-06-2013, 11:23 PM   #17
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QuoteOriginally posted by carrrlangas Quote
I think it is totally possible and makes sense for very specific applications. Think of the Matrix metering. It has 77 segments which are measured individually and then compared with a database to determinate best Av and Tv values. Now, for a very simple "ETTR routine" that attemps to save all the data, it could be something like:
- Read all 77 segments and find the brightest one.
- set Av and Tv for the brightest segment, overexposing 2 stops (or whatever is the threshold is for a specific sensor)

There could even be a new database made with ETTR into account so that you can broaden the cases where it works (If you do want to clip some areas for example)
I don't think this would make much difference from using multi segment metering with exposure compensation.
As light meter only measure average light level in each 77 segment, it will often miss detecting brightest light. (FI when the light is smaller than a segment or the light is part of several segments). It's only if the bright light will be covering a full segment it will work in a predictable way, but that might not happen in 80% of the shots.

The light meter probably need at least 1000 segment do be useful for this, but it might need many more segments than that for it to be something you really can trust for every shot.
09-07-2013, 03:16 AM   #18
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QuoteOriginally posted by SoftwareArtifex Quote
It would have to make a histogram internally to do that.
It should be perfectly possible in live view as the sensor is already seeing the whole picture. I remember seeing such a feature on some bridge camera, I think it was a Fuji but not sure.

To do it in OVF mode you would need an exposure meter sensor with at least 10s of K points and covering the whole field of view, which is effectively a second image sensor, just lower resolution. If I'm not mistaken some high end (expensive) DSLRs do have such exposure meters.
09-07-2013, 03:41 AM   #19
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I feel like most modern cameras do expose to the right -- almost tending to over exposure. I tend to shoot my K5 at EV-1 in order to protect the highlights from blowing out.

09-07-2013, 03:49 AM   #20
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It just occurred to me that even with OVF there is a way to do it, though perhaps not applicable in all situations.

All that is needed is shoot the picture, make a quick analysis (automatically that is) and then shoot a second one with reduced exposure if there are blown highlights, or even increased exposure if the full range is not being used.

For the blown highlights there would still be a bit of 'guesswork' needed by the firmware as it wouldn;t directly know by how much the highlights were blown but I guess some clever algorithms could be made to get a reasonably good 'educated guess'
09-07-2013, 06:47 AM   #21
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QuoteOriginally posted by lister6520 Quote
All that is needed is shoot the picture, make a quick analysis (automatically that is) and then shoot a second one
I was thinking along the same lines myself. Essentially have the camera do automatically what we now do manually - Momentarily expose the sensor just for the purpose of being able to create a hgram to pass on to the firmware where proper aperture or shutter or ISO is determined and then finally a real exposure of sensor is made all with only one click of the shutter button.

Sounds a bit clumsy and slow for on the fly shooting but maybe...

Another variation of above is have a "Set Ev" button. Where the above is done for the purpose of just setting the Ev correctly for that instant in time and if, over time, the photographer thinks the lighting has changed enough it's easy to just hit the button again. While not ideal it would be a huge improvement over the trial error method we now use.
09-19-2013, 11:21 AM   #22
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Olympus does that

Olympus dSLRs have a highlight and shadow priority. The former basically tries to expose an image so there is no blown highlights, so it shoots to the right. I think bunch of other cameras might have that too.
09-20-2013, 01:14 AM   #23
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QuoteOriginally posted by wildman Quote
In theory I understand and agree.

In practice no. In my kind of shooting, mostly birds in the wild, I just don't have the luxury of lavishing that much time on getting all the details of the tonal range of any given shot exactly right out of the box. Most of time I have been waiting for a particular species to show for hours and the most I can realistically hope for is to be 95 percent right and worry about the remaining 5 percent in PS. Nothing for hours than 50 frames in 3 mins. Realistically I just hope for things to be optimal for my particular situation not perfect. We are talking wildlife not landscape or studio work.
For shooting iris and wild life, then thie real point is to use spot metering and meter manually off the spot on the bird you wish to protect.

If you are waiting hours for the bird to show up, you have ample time to keep the exposure adjusted for the ambient light conditions, no problem, you also know what you are shooting and the range of colors, and shades (light vs dark) you will get, and should be able to set everything manually to get it perfect

09-20-2013, 03:08 AM   #24
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QuoteOriginally posted by rrstuff Quote
Olympus dSLRs have a highlight and shadow priority. The former basically tries to expose an image so there is no blown highlights, so it shoots to the right. I think bunch of other cameras might have that too.
Isn't Olympus HI and SH metering just spot metering with EC added?

Last edited by Fogel70; 09-20-2013 at 03:13 AM.
09-22-2013, 06:15 AM   #25
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QuoteOriginally posted by Fogel70 Quote
Isn't Olympus HI and SH metering just spot metering with EC added?
I don't know how it works exactly, but it does achieve something along the lines of ETTR or ETTL. Usually it is rather aggressive though and under-, or overexposes the image. I haven't used it much as a result.
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