[WONTFIX] Pano: Merge different raw histos of a scene and return "best" expo

Started by Simdub, May 26, 2013, 02:46:19 PM

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Simdub

Hello everybody ;).

Now that we have raw histograms and AUTO-ETTR, I was wondering if it was possible to merge several raw histogram in order to have one histogram that represents the whole scene and then maybe we could use a ETTR-like method to adjust the settings (iso or shutter speed or focal). It would be very usefull for panorama makers (either 360° pano makers and just landscapes pano makers).

Just one example to clarify what I mean: Let's say I'm in a room, I have a Wide-angle lens, I want to shoot a 360° pano of the room but I have to shoot in manual mode and keep the same setting for all the shots. The thing is to choose the correct expo settings and it can be very tricky even in simple situations. So would it be possible, for example to be in live view and collect raw histogram of 4 differents places in the room (without moving shutter system like in silent mode, "just" collect from liveview) and then merge them in one raw histogram (or other methods) and use ETTR-like methode to adjust our expo settings so we're "sure" (there may be exceptions) to have the best exposition?

It's just a thought but I think it would be another plus for ML. Let me say what you think, and if you think it's doable.

PS: When I say "merge raw historgam", I mean "add up quantities of black/white/middle in one histogram". I don't know if you understand what I mean ;)?

Marsu42

Quote from: Simdub on May 26, 2013, 02:46:19 PM
It's just a thought but I think it would be another plus for ML. Let me say what you think, and if you think it's doable.

I know what the issue is - but a "lock ettr" feature sounds more resonable to me, i.e. point the camera to the brightest scene in the panorama and then ettr for that in m mode, locking that exposure for the rest of the panorama?

Simdub

Quote from: Marsu42 on May 26, 2013, 08:13:55 PM
I know what the issue is - but a "lock ettr" feature sounds more resonable to me, i.e. point the camera to the brightest scene in the panorama and then ettr for that in m mode, locking that exposure for the rest of the panorama?

Yeah it could be another option but I think that pointing the brigthest scene with ettr (like a window) would underexpose all the scene, it will in fact. But ETTR lock is interesting tough. Instead of pointing the brightest scene, we could point the mid-exposure part of scene. But the probleme is that we don't know where this part is in our scene (room). Like you said we can already do ETTR lock, sort of, we just have to look the settings that auto-ettr gave us and put it off and let this settings in the Manual mode.

I think that a "global" histogram of the scene will be much more accurate in the representation of the exposition of the scene. We would see if it's globally more dark or shiny and then the adjustement will be set in consequences (with auto-ettr for example). But I understand what you said ;).

Marsu42

Quote from: Simdub on May 26, 2013, 10:25:23 PM
I think that a "global" histogram of the scene will be much more accurate in the representation of the exposition of the scene. We would see if it's globally more dark or shiny and then the adjustement will be set in consequences (with auto-ettr for example). But I understand what you said ;).

Nothing against your idea, I'm just wondering if it's too specialized for general ml adoption while an "ettr lock" would be more intuitive because most users already know about "expo lock" in the standard Canon firmware ... if Ml would just "ettr lock" when "expo lock" button is pressed, there would be nothing new to learn. But just my 2ct since I'm not going to implement either :-p

Simdub

Yes, you're probably right ^^. I totally agree it would be more an advanced setting and you're vision is surely more intuitive! It was just a thought so that the discussion is lunched :). But to be honest, I suggested that because I was thinking that maybe it's "just" a matter of addition in a "table" of values. And instead of taking one picture (with one histogram), I thought "maybe just take 3 others and merge them in one" so we're back in the initial situation. And in the menu we would "just" choose on how many frame we want that auto-ETTR will be based it won't add a new menu or something ^^. Once again, it's just some suggestions, and it's nice to discuss with somebody over that :)

Simdub

It would look something like that ^^:



And it would be "1" by default so that it won't affect those who don't see any utility in that ;). Once again, just pure suggestions.