Dual ISO - massive dynamic range improvement (dual_iso.mo)

[a1ex]

This is quite interesting... definitely makes sense with the fact that the dual-ISO giving correct exposure feedbacks because its actually reading it 'deeper' within both ISO's as oppose to just one.

Not sure what you mean - the zebras in the dual ISO image from Audionut are wrong (it's a bug).

[ebeigarts]

I have created homebrew tap for Mac OS X users, so that it is easier to build cr2hdr with dcraw.
https://github.com/ebeigarts/homebrew-magic-lantern

[DeafEyeJedi]

Not sure what you mean - the zebras in the dual ISO image from Audionut are wrong (it's a bug).

I guess I read that wrong from Audionut's images. For some reason I thought it meant that Dual-ISO would give much closer to perfect reading on the exposures regarding zebras than off from a single ISO.

[crazyklaus]

Thank you a1ex and the other contributors for providing this tool to get rid of the nasty canon read noise!

I've done some test shots with the 50D and ran into rather more trouble than expected. Here are two files that are giving me trouble. I'm using the cr2hdr.exe from the first post on Win 7 32bit.

0052.cr2 won't process without error and 0065.cr2 keeps the interlacing lines through the processing.


_UAL0052.CR2
_UAL0065.CR2

[Audionut]

Both of those images process fine with the latest 20bit experimental branch.

https://dl.dropboxusercontent.com/u/34113196/ML/dual_iso/cr2hdr_20bit.exe

[kyrobb]

Is there a 20 bit cr2hdr for OSX?

[DeafEyeJedi]

Is there a 20 bit cr2hdr for OSX?

There are few options to choose from regarding OXS:

-@danne's app cr2hdr-r

-LR5 plugin

-a1ex's binary cr2hdr (use with Terminal)

-MLVFS

[Mare]

Is there a cr2hdr for windows?
Best regards and Thanks

[walter_schulz]

First page

[Mare]

Thank you for your help and advice. All the best to dev's, ... I'm not all the time in front of my comp, more behind my camera. So please understand, ...

Keep on rockin'

[oc_masta]

Can the 7D do the alternating scan line HDR with the RAW video module?
or is that only possible with the 5d mk2/3?

[Walter Schulz]

http://www.magiclantern.fm/forum/index.php?topic=13597.0

[HondaATC]

I need some guidance - I've been using ML on T3i with Dual ISO pretty much ever sine it was released and had really good results.

I've since upgraded to a 5D3 (Merry Christmas to myself ) with latest nightly build and the field is a bit different in that I set the base ISO via the Canon menu, and then teh secondary one via ML, which is fine, I got that part.

What I *am* a little confused about is, how exactly to set this based on my shooting style. I have learned you can use the +/- EV settings to couple with automatic ISO mode which seems very handy. In practice on editing the files though, I am not getting near the results and dynamic range I was on the T3i shooting say 100/800 and then manually under exposing a stop to get color and clouds in the sky in addition to well lighted scenery-this is basically my intended end use.

I have the 5D3 set to -3EV and I just can't seem to duplicate my previous results, I can't bring out the highlights. 

If anyone can help me fully understand the menu choices and usage of this, I'd like to help write a small guide for other poor souls like myself

[garry23]

@HondaATC

Quick response as it's Christmas :-)

I have found the 'best' workflow to be A-ETTR and Dual.

That is set Dual to what you want, eg 100/800, say.

Set your ETTR parameters, eg I put all to 0, apart from % to cover any speculars.

Comprise and focus.

In manual. my choice, set the ETTR for the scene.

Take a dual capture.

Process in LR.

Hope this helps.

Cheers

Garry

[HondaATC]

Got it Garry, Thanks for the reply, I've been able to play around with it a bit and am getting good results again finally

Quick question - I am seeing a bit of funky pinkish/green bending in certain areas, basically in high contrast areas where you would have some Chromatic Aberrations with a typical photo. Not at all prevalent unless pixel peeping, but wanted to mention it none the less. Could the experts have a look see and let me know whether this is typical/expected or not? 5D3, with the new 16-35 F4L lens, using 100/1600 iso setting.

http://tinypic.com/r/o05u36/8

[dubzeebass]

Quick question - I am seeing a bit of funky pinkish/green bending in certain areas, basically in high contrast areas where you would have some Chromatic Aberrations with a typical photo. Not at all prevalent unless pixel peeping, but wanted to mention it none the less. Could the experts have a look see and let me know whether this is typical/expected or not? 5D3, with the new 16-35 F4L lens, using 100/1600 iso setting.

Throw it out the window it's broken and you don't know how to read first posts and basically any post in this thread.

[HondaATC]

I only shot about 10,000 with my T3i and never had this issue, hence the question.

[dubzeebass]

I only shot about 10,000 with my T3i and never had this issue, hence the question.

Must be broken. Should throw it out or stop giving it so much LSD

[HondaATC]

Okay then. For anyone else, I ran a Chromatic Aberration removal on the photo in LR after playing with the sliders a bit and it went away entirely, and also on another photo I had in the back yard of some white fence rail. Its not like it had that effect on every one of them in a consistent manner like typical CA, so thats what I was asking.

The T3i had some aliasing jaggies and moire patterns in shingles from time to time which I am accustomed to, but never produced anything quite like this with the color banding.

[rpt]

Which sliders did you play with for CA removal?

[HondaATC]

I don't have the RAW files here at home to do a direct comparison, but I'll share what I did.

I went into develop mode, (LR 5.x), Down to lens correction. I applied the normal Lens distortion correction process, and then started playing around with these, and wound up with pretty decent results somewhere in this neighborhood (I went from memory to show here, ymmv).


http://tinypic.com/r/m81ov8/8



I do not have the RAW or completed photos I edited here at home, perhaps later today I'll be able to post a before and after.

[rpt]

Ok, thanks.

[wrqcn]

Thank you very much ! I use ML in China , it's so nice .

[wrqcn]

but my english is so poor ,hard to use it.

[HondaATC]

I wanted to give an update on my experience and success in removing the color banding in patterns on photos. I am in real-estate and therefore am around a lot of brick and patterns when using dual ISO. Attached is a screenshot with a before and after, when using some of the color correction and CA tools in Lightroom. The photo is at a 100% crop in these screen caps, a tiny bit of the green color banding in the brick pattern is still visible, but when you shrink it down to a usable size, you'll never notice it.

Hope this helps and is useful for others.

http://wgolightly.smugmug.com/Misc/i-tG8mnXH/0/O/DualISOCorrections.jpg