Dynamic Range - Try it for yourself, conclude for yourself: 5D III vs. A7r

[LetTheRightLensIn]

Well I have to say I sure as heck could've used more DR the last few days. On a fast pace, with others some of whom were not into photograph, tons of ground to cover, often fast changing and soon fading light, so much to see, even when multi-shot tripod HDR would've worked only had time to set up the tripod once.

You don't need a tripod to shoot an HDR. In fact, you don't even need one second. Just shoot a bracketed burst, and use software to obtain perfect alignment in post.

I wasn't entirely happy with that technique when I tried it once before, but maybe I should have tried it again for a few shots where there was no wind/water/swirling mists, maybe it would've worked a few times at least to some degree of OK. Just today that would've never worked as the breeze was blowing stuff around and forget it though. And sometimes, also, it sets the shutter speed too low to work out hand-held for the shot with more exposure, so if you are just at the border you can maybe shoot at ISO100/200 if the sensor had more DR, but fall into hand shaking issues if it doesn't, which would've been a scenario for some of the shots from yesterday.

 

[Eldar]

I am still amazed over the number of posts this topic is able to produce. I hope Canon is paying us some attention.

To me it is rather simple. If I shoot images and the histogram shows I have covered what I wanted covered, I am, from a DR perspective, good. If the histogram shows that I hit either the floor or ceiling, I'm either irritated over a poor exposure setting, or, especially when I'm in the basement and through the roof, with shadows black and highlights blown, in the same picture, I want more DR. I have quite a few of those, where I have to choose which end I want to give priority and have black shadows or blown hightlights in the other end.

Yes, I could in some cases use HDR and bracketing, but as Lee Jay also points out, when things are moving I find that to be a poor option at best. People, wind in trees, flowing water etc. requires one-shot images.

For people to form their own opinion, I suggest they go back and study the histograms of some of their more contrasty images and see how many (if any) would benefit from more DR.

 

[ChristopherMarkPerez]

I think this suggestion is a perfect way to find out if the kinds of shooting situations a person finds themselves in requires more dynamic range. I put requires in italics because, if a shooter thinks carefully about what they're doing, I'll bet they can find a way to manage extreme contrast ranges in fast moving situations where HDR might not be possible.

I seldom encounter any problem. The reason is likely tied to my long history of controlling contrast from Back In The Day when the only light sensitive material available was film. Working in silver halide for far too many decades taught me the value of light controls to manage contrast.

... I suggest they go back and study the histograms of some of their more contrasty images and see how many (if any) would benefit from more DR.

 

[Lee Jay]

I am still amazed over the number of posts this topic is able to produce. I hope Canon is paying us some attention.

To me it is rather simple. If I shoot images and the histogram shows I have covered what I wanted covered, I am, from a DR perspective, good. If the histogram shows that I hit either the floor or ceiling, I'm either irritated over a poor exposure setting, or, especially when I'm in the basement and through the roof, with shadows black and highlights blown, in the same picture, I want more DR. I have quite a few of those, where I have to choose which end I want to give priority and have black shadows or blown hightlights in the other end.

Yes, I could in some cases use HDR and bracketing, but as Lee Jay also points out, when things are moving I find that to be a poor option at best. People, wind in trees, flowing water etc. requires one-shot images.

For people to form their own opinion, I suggest they go back and study the histograms of some of their more contrasty images and see how many (if any) would benefit from more DR.

The in-camera histogram? The histogram of the default raw conversion? What histogram are you talking about?

 

[Marsu42]

To me it is rather simple. If I shoot images and the histogram shows I have covered what I wanted covered, I am, from a DR perspective, good.

In that case, you're throwing away dynamic range because Canon's histogram only covers the jpeg range. To make really use of the dr, use Magic Lantern with the raw histogram and let it auto-ettr the shot.

 

[privatebydesign]

To me it is rather simple. If I shoot images and the histogram shows I have covered what I wanted covered, I am, from a DR perspective, good.

In that case, you're throwing away dynamic range because Canon's histogram only covers the jpeg range. To make really use of the dr, use Magic Lantern with the raw histogram and let it auto-ettr the shot.

It is even worse than that, if you have your camera set to sRGB it gives warnings when they get to that colour space which is even earlier than Adobe RGB and way before the cameras capabilities. If your file names do not start with an underscore then you useing a very unrealistic histogram.

That is why I am always going on about optimal exposure for RAW file comparisons, people earnestly come back with 'but the histogram was touching' but that isn't the optimal exposure, especially in DR limiting scenes.

I'd love some ML capabilities on the 1 series but know they won't be ported there.

 

[Marsu42]

It is even worse than that, if you have your camera set to sRGB it gives warnings when they get to that colour space which is even earlier than Adobe RGB and way before the cameras capabilities. If your file names do not start with an underscore then you useing a very unrealistic histogram.

Whatdoyaknow, that's news to me - thanks, you learn something new every day around CR

 

[AcutancePhotography]

Whatdoyaknow, that's news to me - thanks, you learn something new every day around CR

There IS good information on CR. It is just a shame that one has to wade through all the crap to find the pearls.

 

[Eldar]

I was not going to make a big case out of this, but what you see on the camera is what you see on the camera. You need to be able to read that properly. And yes, what you see there is nor correct, but you need to judge your settings based on what it tells you. At least that's what I do. The histogram I referred to was LR, looking at the Raw files. If that is incorrect also, I'd appreciate a clarification.

 

[Marsu42]

The histogram I referred to was LR, looking at the Raw files. If that is incorrect also, I'd appreciate a clarification.

Depends what LR process version and camera you're using - with my 60d the LR histogram is not correct because highlight pulldown conjures data out of nothing on the right side. With my 6d, the raw conversion seems to be different as the LR histogram is correct right from the start.

 

[Lee Jay]

I was not going to make a big case out of this, but what you see on the camera is what you see on the camera. You need to be able to read that properly. And yes, what you see there is nor correct, but you need to judge your settings based on what it tells you. At least that's what I do. The histogram I referred to was LR, looking at the Raw files. If that is incorrect also, I'd appreciate a clarification.

The default conversion gives you much less dynamic range than is available in the raw data. Even if both highlights and shadows are clipped in the default conversion, using -highlights and +shadows may recover several stops of DR from the ends of the histogram.

 

[Zv]

Back up a second. So even if you shoot RAW the histogram in camera is only displaying the color space you've chosen? So does that mean I should set my camera's color space to Adobe RGB just so I get a more accurate histogram?

I have also noticed the default conversion in LR seems to clip earlier than some of the others like Faithful or Neutral. I feel like I should be tinkering with that in some way to maximize latitude. For most of my stuff the highlight slider takes care of my DR needs. It's hard to gauge just how far to ettr without ML. I had it on the M but it got buggy with the EF-M 11-22mm lens for some reason so now I'm just doing without. Maybe I should install it on the 5D2. Not sure I need all those features but this RAW histogram thing has got me re-interested. ???

 

[Lee Jay]

Back up a second. So even if you shoot RAW the histogram in camera is only displaying the color space you've chosen?

And the in-camera processing (especially contrast and saturation) you've chosen.

 

[lintoni]

Back up a second. So even if you shoot RAW the histogram in camera is only displaying the color space you've chosen? So does that mean I should set my camera's color space to Adobe RGB just so I get a more accurate histogram?

I have also noticed the default conversion in LR seems to clip earlier than some of the others like Faithful or Neutral. I feel like I should be tinkering with that in some way to maximize latitude. For most of my stuff the highlight slider takes care of my DR needs. It's hard to gauge just how far to ettr without ML. I had it on the M but it got buggy with the EF-M 11-22mm lens for some reason so now I'm just doing without. Maybe I should install it on the 5D2. Not sure I need all those features but this RAW histogram thing has got me re-interested. ???

This is worth reading:
http://www.magiclantern.fm/forum/index.php?topic=12096.0

 

[privatebydesign]

Back up a second. So even if you shoot RAW the histogram in camera is only displaying the color space you've chosen? So does that mean I should set my camera's color space to Adobe RGB just so I get a more accurate histogram?

Yes.

This is the kind of thing that enables people to play with the top 5-10% of a systems potential IQ, it is the kind of thing that allows us to up our game in the smallest steps that when put together end up making an intangible but noticeable difference to our output. It is the kind of thing camera testers never have the time to explore, and people who do "comparisons" never evaluate. It s the kind of thing that makes people say "you couldn't do that to mine" or "my XXX was a dud, because it's files never looked like that".

Every single RAW file I ever shot starts with an underscore.

 

[Eldar]

The default conversion gives you much less dynamic range than is available in the raw data. Even if both highlights and shadows are clipped in the default conversion, using -highlights and +shadows may recover several stops of DR from the ends of the histogram.

Agree.

 

[Zv]

Back up a second. So even if you shoot RAW the histogram in camera is only displaying the color space you've chosen? So does that mean I should set my camera's color space to Adobe RGB just so I get a more accurate histogram?

I have also noticed the default conversion in LR seems to clip earlier than some of the others like Faithful or Neutral. I feel like I should be tinkering with that in some way to maximize latitude. For most of my stuff the highlight slider takes care of my DR needs. It's hard to gauge just how far to ettr without ML. I had it on the M but it got buggy with the EF-M 11-22mm lens for some reason so now I'm just doing without. Maybe I should install it on the 5D2. Not sure I need all those features but this RAW histogram thing has got me re-interested. ???

This is worth reading:
http://www.magiclantern.fm/forum/index.php?topic=12096.0

Thank you for this. When I started looking into ML I couldn't find a detailed explanation of all the features. Now I know what the numbers mean!

Bookmarkin this!

 

[Zv]

Back up a second. So even if you shoot RAW the histogram in camera is only displaying the color space you've chosen? So does that mean I should set my camera's color space to Adobe RGB just so I get a more accurate histogram?

Yes.

This is the kind of thing that enables people to play with the top 5-10% of a systems potential IQ, it is the kind of thing that allows us to up our game in the smallest steps that when put together end up making an intangible but noticeable difference to our output. It is the kind of thing camera testers never have the time to explore, and people who do "comparisons" never evaluate. It s the kind of thing that makes people say "you couldn't do that to mine" or "my XXX was a dud, because it's files never looked like that".

Every single RAW file I ever shot starts with an underscore.

I can't say it's ever been an issue for me to have an accurate histo. I usually just expose to the right but lately I was wondering about this kinda thing and it makes so much sense now after reading that link about RAW histograms. Damn, why don't Canon put that feature in their cameras by default?!! WHY?! I feel like I just had one of them lightbulb moments!

Finally, this topic is paying off! Woohoo!!

 

[DominoDude]

If anything, I've learned that, despite trying to ETTR by looking at the histogram on the camera, I can overexpose even more than I imagined. I knew that the histogram was only based on the jpg-thumbnails, just as the image I see on the display, and that it is a result of the PictureStyle and Colourspace.

The use of ML's Auto-ETTR and the RAW-based histograms have shown that I can be a lot more brutal when I choose my exposure. But the limiting parameter are the widest aperture of the chosen lens, and it dictates the combinations of shutter times and ISO I can pick to get my desired/needed exposure. I've learned that I, most of the time, need rather short shutter times to not introduce shake, and then I end up needing to increase the ISO to get my histogram to crawl over more to the right.

I think we could all benefit from a redesign of the Canon sensors. A redesign that incorporates deeper photon wells (more electrons can be stored and thus giving us a greater dynamic range), and measures taken to lessen the banding tendency. From texts I've read, by Stanford university researchers, the A/D-converters are less crucial for a high DR in optical sensors.

 

[Loswr]

Back up a second. So even if you shoot RAW the histogram in camera is only displaying the color space you've chosen? So does that mean I should set my camera's color space to Adobe RGB just so I get a more accurate histogram?

When you shoot RAW, the camera generates a small JPG preview image that's embedded in the RAW file container. That image is what you see during the on-camera review, and it's what's used to generate the histogram and highlight warning (blinkies). All in-camera settings are applied (color space, ALO, picture style, HTP, etc.).

If you don't mind somewhat funky images for on-camera review, you can use UniWB to get a histogram that better approximates the RAW data.