Messages

1

Modules Development / Re: Dual ISO - massive dynamic range improvement (dual_iso.mo)

« on: July 25, 2016, 07:06:32 AM »

If you upload the two raw files that you expect to be identical, I can take a look.

Editing the source code is probably the best option right now.

I appreciate it, and I'm sure with enough cr2hdr tweaks we could get those two particular shots to converge, but those tweaks would go out the window if the dual ISO EV ratio (or other settings) changed, wouldn't they? Indeed my lowest max ISO is 400.

Yes I think looking to the shoot code would be a better solution. I'd already forked it to work on a couple more options for ettr timelapses, so I'll also see about locking iso entirely. Just could not get the ubuntu virtual box to compile modules due to its age (not a linux person), so I'm going to try my luck with cygwin.

2

Modules Development / Re: Dual ISO - massive dynamic range improvement (dual_iso.mo)

« on: July 24, 2016, 08:05:14 AM »

Thanks for the info. Yes, it needs deflicker, but I'm quite sure the flicker is due to switching to dual ISO; the images on either side of the transition show absolutely no flicker. It's more than an exposure change though; if I correct the brightness I can get it very close, but there is still a subtle difference in color.  If possible I want to try to find shoot settings that don't cause that flicker to begin with and give me a very linear post process workflow, so the last option sounds like exactly what I'm looking for. How would I force ETTR to only adjust the shutter without changing ISO? Even with link to dual ISO disabled, ETTR still adjusts the base ISO.

3

Modules Development / Re: Dual ISO - massive dynamic range improvement (dual_iso.mo)

« on: July 23, 2016, 09:39:28 AM »

Hey guys,
I've used ML for several years and have been getting more into timelapses recently, using auto ETTR to shoot my first holy grail sequence which turned out beautifully. The past few days I started adding dual ISO to the mix and, while the individual images look incredible, I've been having some issues getting it to work seamlessly in timelapses.

I've spent the past couple days searching the forums but I haven't found my issue addressed, which is: doesn't allowing ML to turn dual ISO on and off as needed introduce an incorrectable color/exposure change in the final result due to the extra processing step (cr2hdr)? I just got back from a test holy grail timelapse and compared sequential (10s) images before and after ML enabled dual ISO as it got darker. With identical exposure and raw settings, the two images show a huge change in color and exposure. Also the dual ISO images have a few more pixels (5202x3465 vs 5184x3456). I know my SNR values were probably wrong as it actually disabled dual ISO as it got even darker, but I think the question is still valid in changing light conditions.

I'm shooting on a T2i using the latest ML (2016Jul09), and BarracudaGUI pointed at the cr2hdr executables from the latest zip. First I tried feeding the raw CR2s into Barracuda, and the dual ISO images were extremely different. Then I read someone on the forums say they converted all CR2s to DNGs with ACR, then Barracuda, which turned out closer, but still noticeably different.

Has no one else encountered these problems? Am I just missing something in shoot settings or in post?

Here's a comparison of two of these images, both converted to DNG, run through cr2hdr, and set to same raw settings:  http://i.imgur.com/Rg0LpE0.jpg

Thank you for these incredible tools, can't wait to get this working!