Author Topic: Dual ISO - massive dynamic range improvement (dual_iso.mo) (Read 2223757 times)

sebamax · « **Reply #175 on:** July 19, 2013, 07:31:19 PM »

ISO 100 is better but the DR is much lower than dual ISO. Using ETTR: external exposure the shutter was 800 (ISO 100-F2.

and internal exposure the shutter was 50 (ISO 100 F2.

.

a1ex · « **Reply #176 on:** July 19, 2013, 08:07:15 PM »

What shutter speed did you use for dual ISO?

horshack · « **Reply #177 on:** July 19, 2013, 08:40:53 PM »

Quote from: sarangiman on July 18, 2013, 11:19:38 PM

But typical 'engineering' DR calculations using SNR of 1 as the lowest signal don't consider shot noise, correct? Therefore, one could still say that the engineering DR is extended to FWC/read noise @ISO 1600, which is ~14EV. If you're using a lower SNR cutoff of, say, 20, then the DR is much more modest (considering the increase in shot noise contributions you mention).

Right, SNR goes down but if one uses a 1:1 SNR (like DxO does) for DR calculations then then SNR reduction doesn't affect the DR number.

Danne · « **Reply #178 on:** July 19, 2013, 09:20:25 PM »

A little testing with the dual iso feature. Real cool stuff going on. Feel free to comment.

//D

Danne · « **Reply #179 on:** July 19, 2013, 10:37:26 PM »

Quote from: sebamax on July 19, 2013, 07:31:19 PM

ISO 100 is better but the DR is much lower than dual ISO. Using ETTR: external exposure the shutter was 800 (ISO 100-F2. and internal exposure the shutter was 50 (ISO 100 F2..

I don,t quite get this. Clearly you get the best results here in your movie "iso 100 raw expo internal ettr raw2dng".
Could you explain what your settings were exactly.
Thanks!
//D

a1ex · « **Reply #180 on:** July 19, 2013, 11:03:34 PM »

Pixel peepers: which of these 3 would you choose?

http://acoutts.com/a1ex/bright1.dng
http://acoutts.com/a1ex/bright2.dng
http://acoutts.com/a1ex/bright3.dng

Both are ISO 1600 half interpolated.

driftwood · « **Reply #181 on:** July 19, 2013, 11:44:55 PM »

bright3 better edge. check the curvature of the lamp. bright1 inconsistent. bright2 good balance.

Yep for me bright3 detail wins (see blind edges too). bright1 slightly better in highlight detail - see blind chord. (right click images into new window to analyse). bright2 somewhere in the middle.

Danne · « **Reply #182 on:** July 20, 2013, 12:00:08 AM »

I think bright 1 is nice. The blinds seem smooth and the camera is less aliased than the others.

Audionut · « **Reply #183 on:** July 20, 2013, 03:19:33 AM »

For the window, bright 1. Smoothest edges, least artifacting.

For everything else, bright 2. Bright 1 is a no show, to much aliasing.

Bright 3 has more artifacts. Check the difference between 2 and 3 on the full res samples in the areas I have highlighted below.

Canon eos m · « **Reply #184 on:** July 20, 2013, 03:34:22 AM »

Hi,

Thank to Audionut for supplying the binary install for the dual iso module. Uploaded and now sailing to go. Facing a challenge though and need desperate help. The raw2dng that I downloaded cannot be activated since windows 8 sees it as a threat if some sort and is locking it on my PC. Any idea how to deactivate the security to get the program running?

Second, how do I record stills with the dual iso module? Cold someone post the workflow?

Thank you again and to A1ex too.

sebamax · « **Reply #185 on:** July 20, 2013, 09:54:07 AM »

Quote from: Danne on July 19, 2013, 10:37:26 PM

I don,t quite get this. Clearly you get the best results here in your movie "iso 100 raw expo internal ettr raw2dng".
Could you explain what your settings were exactly.
Thanks!
//D

Hi,
I wanted to try an extreme situation of light.
In the first shoot with the raw module and ETTR module, I pointed out of the window and ETTR suggested me ISO 100-shutter 1.000 F2.8. In the second shoot I pointed inside the room: ISO 100 shutter 60- F2.8.
With dual ISO module (ISO 100-1.600) with ETTR I pointed out of the window and it suggested me ISO 100 shutter 800-F2.8. I processed all in ACR using Highlight -100 and shadow +100.
With dual ISO module it was a little bit difficult using viewfinder to focus.

a1ex · « **Reply #186 on:** July 20, 2013, 11:13:45 AM »

Pixel peepers: which of these two?

http://acoutts.com/a1ex/highlight/a.jpg
http://acoutts.com/a1ex/highlight/b.jpg

sebamax · « **Reply #187 on:** July 20, 2013, 11:33:01 AM »

"a" seems more clear in the curtains

Canon eos m · « **Reply #188 on:** July 20, 2013, 12:08:55 PM »

I agree 'a' seems to be better (crispier).

Canon eos m · « **Reply #189 on:** July 20, 2013, 12:09:50 PM »

A1ex: How do I take still with the dual_iso functionality?

a1ex · « **Reply #190 on:** July 20, 2013, 12:23:02 PM »

To take stills, press the shutter button, then read the first post. Picture quality should be RAW.

So... you all say it's better to have sharper false detail and aliasing artifacts?

To me, it seems better to have less artifacts, even if the highlights are softer. I've updated the converters with the new algorithm, it should print "mean23-vsmooth3". Can you run some tests?

jaybirch · « **Reply #191 on:** July 20, 2013, 02:13:05 PM »

Quote from: a1ex on July 20, 2013, 12:23:02 PM

To me, it seems better to have less artifacts, even if the highlights are softer.

100% Agreed.

Softer images, i can work with. Noticeable artefacts are a no go.

Danne · « **Reply #192 on:** July 20, 2013, 02:17:41 PM »

My vote for the smoother picture with less artefacts definitely.

Stedda · « **Reply #193 on:** July 20, 2013, 02:32:04 PM »

I vote less artifacts.

Canon eos m · « **Reply #194 on:** July 20, 2013, 02:55:20 PM »

My first Dual ISO production. Really am proud for having worked it out!

Link: https://www.dropbox.com/s/i51u04c44yb3t9w/first%20%20dyau%20iso%20video.mov

Canon eos m · « **Reply #195 on:** July 20, 2013, 03:19:17 PM »

Quote from: Canon eos m on July 20, 2013, 02:55:20 PM

My first Dual ISO production. Really am proud for having worked it out!

Link: https://www.dropbox.com/s/i51u04c44yb3t9w/first%20%20dyau%20iso%20video.mov

A still photo using the dual iso functionality

https://www.dropbox.com/s/botulropqxbsjk9/SANDALS%20DUAL%20ISO%20MAGIC%20LANTERN.tif

jaybirch · « **Reply #196 on:** July 20, 2013, 03:41:28 PM »

Starting to get close to a usable settings. This was shot ISO 200-800 .... Exposure was pretty centred, to avoid too much highlight aliasing. Click for 1080p

a1ex · « **Reply #197 on:** July 20, 2013, 03:54:44 PM »

Yes, that's the ideal use case. Main subject covered by both ISOs (full detail), highlights and shadows as out-of-focus backgrounds (no aliasing).

jaybirch · « **Reply #198 on:** July 20, 2013, 04:07:27 PM »

yep... I did a rack focus and once the highlights come into focus, it gets a bit messy, but not too bad.

For now, i think protecting the highlights as much as possible is the best way to go, avoiding artefacts.... Then pulling out the deep shadows. Probably not getting quite such a DR boost, but it gives a more usable image.

GregoryOfManhattan · « **Reply #199 on:** July 20, 2013, 04:14:07 PM »

yes - good to know better use cases may not be the extremes and
to consider the value (thematically and exposure wise) of what's in field of focus.

is raw2dng in unified supposed to be able to process dual iso clips?
tried 5bad65ff8cb8 and it isn't converting a dual shot clip - instead it creates banded DNGs.

easy enough to download a different version.

News:

Author Topic: Dual ISO - massive dynamic range improvement (dual_iso.mo) (Read 2223757 times)