Auto ETTR based on RAW histogram (ettr.mo)

[garry23]

Alex

How about a user choice, ie reset bulb or not :-)

[garry23]

Alex/josepvm

Have experimented more and restricted my workflow to starting in M with AutoSnap, which requires a full press to initiate.

I have ML Bulb Timer enabled, but don't worry about the time (as ETTR will control).

I set Canon ISO to 100 and the exposure at a few sec, eg 4s, (which will be the autosnap test exposure).

I then carry out a full shutter press in M mode.

AutoSnap takes a 4s test exposure (and captures this image to the card).

It then automatically takes the 'real' exposure.

One thing I have noted is that I need to set % highlights higher than in normal ETTR mode, eg 1% or higher. If I don't the ETTR solution doesn't look pushed to the right enough.

BTW my test image has no speculars, it's flat.

So what could be 'better'?

At the moment the user has little feedback on the LE shutter time (I assume the beeps at the start are indicative, eg 3 beeps = 3 mins). Is there a way to flash up the LE time on the screen prior to taking the LE?

Also, as i said previously, this and David M's ND Bulb are complementary. Hence it would be good to have both running.

Bottom line: great feature if you are not too worried about what the actually time is, ie in dynamic Timelapses or where you are taking a still at 'simply' a long exposure. DM's ND Bulb Module is there (hopefully soon) for the occasions when you want a specific time, ie I can dial in my variable ND or change things to ensure a time.

[josepvm]

Tested your procedure, It works fine for me, also.

And yes, after a test shot with only few seconds of exposure, ETTR is able to correctly expose the second shot ( aprox. ~ 1 minute exposure ) So no need to waste time in a very long test exposure, that's great !

I do not see any need to change the highlight ignore setting, I get the exposure that I like  ... but I always set lower ETTR's SNR limits (4 EV for midtones, 1 EV for shadows) than default ones (6 EV for midtones, 2 EV for shadows).  The reason is that I capture mostly landscapes, and I don't want that sky highlights get clipped at all. If the foreground gets too dark, I use Dual-ISO or bracketing.

If you feel that in long exposures you are getting underexposed images, you can increase the highlight ignore value, as you have done, or alternatively increase the SNR limits. I think the second method is more reliable to expose more the shadows and midtones, regardless of the presence or absence of specular highlights.

[garry23]

I set both SNRs to zero, to guarantee no clipping.

If you set SNRs to non-zero you risk clipping.

[garry23]

Alex/josepvm

I thought you may be interested in this post: http://photography.grayheron.net/2015/06/further-le-experiments.html

[DeafEyeJedi]

Definitely a great read and thanks for sharing the link @garry23!

[josepvm]

A nice article, thanks !

[massimo]

Hi,
I tried to use the aettr on my 5d2 but the ISO keep limited to 1600 max, is it by 5d2's auto iso limit?

[dmilligan]

ISOs above 1600 on 5d2 are just digital manipulations and not actually increased analog amplifier gains. Therefore there is no improvement in SNR, and using them is pointless (except for JPEG and h264, but aettr is for raw only). Just increase exposure in post.

[garry23]

If you haven't read this, you may find this of value: http://www.clarkvision.com/articles/iso/

[rsmith02]

[nevermind, redownloaded the package and found this module. It would be nice to have the non-included ones in one place to download, though.]

[Dionisgr]

Good time of day. If you use auto ETTR all the shots turn out overexposed! In Sunny weather, to remove not possible! Is this normal?

[Walter Schulz]

Sample and settings used would be fine.

[Dionisgr]

I apologize for my poor knowledge! Could you point me to where I can find step by step instructions to use Auto ETTR

[Walter Schulz]

Start with https://builds.magiclantern.fm/#/features -> Modules -> ettr (link)

[Dionisgr]

A huge thank you!

[garry23]

Also put all SNRs to off or zero.

[mr.smith]

Many thank you for ML team.

Can you be able to chose MAX ISO(like slowest shutter) when using ETTR?

I am using ETTR and it is very very useful.
But when I am in the dark, the ISO will be 12800(it is 5D3's max ISO) soon.
If I shoot with 12800 ISO, it always appears dead/hot pixels.
SO, I want to chose max ISO(such as 4000) when using ETTR.

If it is possible, please create it on next build.
(Both Nightly Build and Experimental Build, please.)


*Canon 5D3

[a1ex]

Asked and answered.

I'd be also interested to see a proof that ISO 4000 (or other close value) gives less hot pixels compared to ISO 12800 (at identical shutter speeds, of course).

[mr.smith]

Hi,

I uploaded the pics.(5D3 1.2.3 2017March30build, 1920x1080)
Lower ISO also has dead/hot pixel.
But it does not stand out and less than higher ISO.
Therefore, I want to be able to chose MAX ISO(like slowest shutter) when using ETTR.

The ISO will be 12800(it is 5D3's max ISO) soon, although I am in not so dark.
I always think "It does not need 12800 now." and change to 3200 or 6400.
Higher ISO is noiser, so I don't want to use ISO 12800 anymore.

If it is possible, please create it on next build.
(Both Nightly Build and Experimental Build, please.)

ISO3200




ISO6400




ISO12800

[dmilligan]

Higher ISO is noiser

Sounds like you didn't read the link a1ex posted in the previous response.

[a1ex]

To compare the pictures, you need to render them at equal brightness (using exposure adjustments in post).

Here's a similar test done with 6D.

[Psih]

ETTR use 1/2 stop for change exposure. Is it true? If yes, why not 1/3 stop?

[a1ex]

To keep the math simple.

[Psih]

I have some problem, when I using ETTR with 1/2 stop for shooting timelapse and postprocess it with LRTimelapse. LRTimelapse can work only with step 1/3 stop. Can I change some settings ETTR for change step from 1/2 to 1/3?