(Auto) ETTR (Exposure to the Right): -- History & Beginners Guide

[Audionut]

The highlight ignore parameter says, ignore this percentage of pixels in the image.

The sun takes up some percentage of pixels in the image.

Using raw based zebras, you can adjust the highlight ignore setting so that the sun is completely ignored (overexposed), allowing the rest of the image to be ETTR'd correctly.

If you just randomly set the highlight ignore parameter to large, you may find wanted details in the image also being overexposed (rather then only the sun).

[tetsusaiga]

Thanks audionut.  I'm going to give it a try again in a few days.

I have a questions about Auto-ETTR.  When I was shooting the timelapse, I noticed it displayed "Auto ETTR Settled at 1/(shutter speed)" after each picture.  What does it mean when Auto-ETTR settled at a shutter speed?

Also, I was wondering if there is any way to ramp the interval time?  For example, I want the intervalometer to take a picture every 5 seconds.  As the sun is setting and less less light, I want the intervalometer to take a picture every 10 seconds. 

I felt that the sunset timelapse I made the other day was moving too fast.

[Audionut]

What does it mean when Auto-ETTR settled at a shutter speed?

"Hey, I've just looked at the scene you want me to ETTR, and I reckon this is the shutter speed you need.  So I am going to settle on that shutter speed.  Good luck"

Also, I was wondering if there is any way to ramp the interval time?  For example, I want the intervalometer to take a picture every 5 seconds.  As the sun is setting and less less light, I want the intervalometer to take a picture every 10 seconds. 

You should be able to do that with dmilligan' Advanced Intervalometer.

[tetsusaiga]

Audionut, thanks for replying.  By the way, thanks dmilligan for creating adv_int.mo.

I read dmilligan's entire thread about adv_int.mo and I'm not really sure how to use this module.  I'm not really sure what keyframes are and I'm not sure why it's set based on time. 

From what I read, I think keyframes tell ML when to change certain exposure settings (e.g., ISO, shutter speed, and aperture) when the clock on the DSLR reaches that set time.  But doesn't this require you to predict the time of when the sun is setting/rising?

Also, why does dimilligan's example of adv_int.mo change the aperture?  Wouldn't this make something that is in focus, out of focus after the ramping?

Can someone explain to me in very simple terms how Auto-ETTR works alongside adv_int.mo, using the specific example of a sunset timelapse.

What I intend to use adv_int.mo for is to somewhat slow down the daytime portion of my sunset timelapse to kind of match the speed of the night-time portion of the timelapse.  In my recent test with Auto-ETTR (https://www.youtube.com/watch?v=QiwjuJS5Eto&feature=youtu.be), the daytime portion was too fast for my liking, so I wanted to find a way to slow it down - i.e., taking more pictures during the day.  My interval for my sunset timelapse was set to 30 seconds, so I wanted to slow it down by maybe setting the interval to 10 seconds.

I going to continue practicing with Auto-ETTR, deflicker, and dual_ISO, but I would love to move on to using adv_int.mo also.

[dmilligan]

I'm not really sure what keyframes are and I'm not sure why it's set based on time. 

http://en.wikipedia.org/wiki/Key_frame

From what I read, I think keyframes tell ML when to change certain exposure settings when the clock on the DSLR reaches that set time.   

Yes, in "global time" mode. In the other mode, it simply counts frames, so the keyframe "time" is just the frame number.

But doesn't this require you to predict the time of when the sun is setting/rising?

I'm pretty sure that cavemen could do this, or at least the dudes who built Stonehenge...

http://aa.usno.navy.mil/data/docs/RS_OneYear.php

Also, why does dimilligan's example of adv_int.mo change the aperture?  Wouldn't this make something that is in focus, out of focus after the ramping?

It could, and that might be the point. Or, your subject may also easily fit in the smaller DOF of the larger aperture, in which case it wouldn't make any difference. For example: landscapes are typically hyperfocal at infinity even at large apertures, so when there's plenty of light we want to use a smaller aperture for sharper photos, most lenses perform best around f/8, and then when light is low, we sacrifice the extra sharpness for the extra light we get from having the lens wide open (~ f/1.8 or whatever).

Can someone explain to me in very simple terms how Auto-ETTR works alongside adv_int.mo, using the specific example of a sunset timelapse.

I think of it like this:
AETTR sets the proper exposure, using shutter speed and ISO (or only ISO), automatically. adv_int sets more aesthetic or artistic properties such as aperture, focus, and interval time, that the photographer wants manual control over, based on his knowledge.

[mothaibaphoto]

tetsusaiga, try this:
http://photoephemeris.com/

[tetsusaiga]

Thanks again to everyone for helping me out. I would never have thought I could make a partial sunset timelapse until you guys helped me. Once I get paid, I'm going to setup a PayPal account and make a donation.

I wish Canon would learn from you guys, instead of taking stupid (well, not so stupid since we still buy their products) marketing strategies to monetize from their devoted consumers. Just give us what we want, Canon!

As for increasing or decreasing the interval time, I see that the sun sets around 5 at where I live. I want to have an interval of about 5-10 seconds while the sun is out. But I want to increase the interval time to 15-25 seconds as the sun is setting, and 25-40 when the sun is basically completely set.

How can I predict when to set these keyframes and how do I do that?

Also, it's my understanding that, if I use ML deflicker, I need to compensate 3-5 seconds for the deflicker module to do its thing, in addition to the 2-3 seconds for the camera buffer to clear. That's a total of about 8 seconds just to do in-camera processing. Is this true?

Thanks again for everything. Once I get a hold of these modules, I want to contribute to the community by writing a thread for newbs like me.

[Anton2707]

Is possible to use auto ettr with bulb timer for day to night timelapses?

[Lars Steenhoff]

Yes you can create a picture style that has a lower curve so it looks under exposed compared to the normal picture styles.

[keepersdungeon]

Hello, I've been trying to use ETTR for the 1st time,  I have a 6d, but I think I'm using wrong, coz I don't see any difference, and the histogram isn't changing much (to the right as I see in some photos ), and the highlight ignore isn't making any difference as well, I tried at 30% and 0.1%.
Any help or tips would be great. Thanks

[Walter Schulz]

Test setup for highlight ignore:
Put a white paper on a black cloth/paper and change highlight ignore percentage. At higher ignore levels ETTR will change exposure and overexpose your paper.

[keepersdungeon]

Ok so I did the test, and with higher highlights ignore value ETTR changed the Shutter speed from 1/40 to 10" and it did overexposed the paper as u said.
But I thought that this setting is so it doesn't over expose the highlights, to help with astro shots and light polution, no?

[Walter Schulz]

If you don't want to have any highlight overexposed you should use 0%.
Settings >0% are for landscape (for example) where the sun is in the frame. It would not make that much sense to have the sun exposed correctly. And for highlights in architecture where sun is reflected in small areas.

[keepersdungeon]

Oh ok I got it all wrong :/ thanks again for the help. So basically ettr module is just an auto mode to set the exposure time and iso for ur shot,  did I get it right now?

[Walter Schulz]

Yes, that's all about.
May I ask where you got it wrong?

[keepersdungeon]

I thought it pushes ur graph to the right without long exposure. And the highlights ignore though that it blocks highlights from over exposing even at  long exposure, that's why I talked about the night light pollution earlier.

[guisquil]

Hello,

Is there a way to change the default lower ISO from say 100 to 160? I'm using a Canon 7D and I would like to have it be 160 ISO.

Thanks

[dmilligan]

Why would you want to do that? I can't think of any valid reasons. 160 is a digital ISO anyway.

[guisquil]

"Why would you want to do that? I can't think of any valid reasons. 160 is a digital ISO anyway."

http://shootintheshot.joshsilfen.com/2010/05/13/canon-hd-dslr-native-iso/

[Audionut]

http://www.magiclantern.fm/forum/index.php?topic=10111.0

[guisquil]

http://www.magiclantern.fm/forum/index.php?topic=10111.0

Thanks for the info.

[extremelypoorfilmaker]

Thanks!

[Brawl]

I'm trying to make a little test. I'm in low light ambient. If I press "set" for the ETTR there is a bip and than a message on the screen of my 7D that say "Expo limit reached".
When there is this message it means that the technique will not work?

thx

[Walter Schulz]

Access Auto-ETTR submenu and change exposure time limit.

[l_d_allan]

I'm wondering if my understanding of ETTR and the resulting rule-of-thumb (ROT) is more or less correct. Or flawed?

And sorry if this has been addressed before within this 170+ post thread and 4 pages. I did read several pages and didn't notice it being addressed.

To me, if the camera's base ISO (typically 100 for Canon) isn't suitable, then ETTR may not be all that useful or appropriate. It's mostly an issue at lower light levels, like dusk, dawn, night, interiors, landscapes, etc.

This could involve a moving subject demanding a relatively high shutter speed to "freeze" the action, or not enough light (even with tripod), or perhaps too much wind for tripod and long exposure. The use of Dual-ISO is also a factor, and my impression is that Dual-ISO increases the advantages of using ETTR with ISO 100.

If ISO 100 isn't appropriate for a specific capture, then you can settle for the histogram not going all that far to the Right, or increase the ISO to get the histogram to the Right.

But when you increase the ISO, noise increases and the tonality quality decreases. It gets to be a trade-off of whether ISO is the priority, or shutter speed.

I think with an ISO-less sensor like Exmor's, you'd tend to favor ISO 100 and whatever shutter speed that results in, within reason. With Canon sensors not being ISO-less, it's less clear-cut what to do when you can't use ISO 100.

Or not? I find I learn more when someone "corrects the error of my ways".