Dual iso

[togger]

I have just installed ML & i am trying to work out what the dual iso actually does & how to use it properly in photos on my 7D.
Any help much appreciated.

[garry23]

Look at dual as being able to take two exposure brackets x Ev apart, but both embedded in a single image. Thus you don't have to worry about image to image movement.

Usually x is less than 3 Ev, and rather than bracket using shutter speed, you bracket using ISO.

To achieve this, dual alternates the ISO every two sensor scan lines. The 'bracketed' image is then reconstructed in post. You can not not use a dual image on its own. BTW if you zoom into a dual image you will see the alternating ISO data.

I personally use dual with ETTR.

I first set  an ETTR exposure and then take a dual of the scene.

This way a get an optimum data capture with a wider DR than without a dual.

The downside is potentially a little lose in data, but I don't usually see this, and more list processing.

Just experiment and be amazed.

Cheers

Garry

[Walter Schulz]

http://www.magiclantern.fm/forum/index.php?topic=7139.0
You will find some shots taken with Dual-ISO with some infos here: http://www.magiclantern.fm/forum/index.php?board=20.0

Dual-ISO video not available on 7D yet.

[garry23]

I officially hate the iPad auto correct, especially when I don't proof read my posts 

[togger]

Thanks for your replies,but maybe i am thick, so a dual iso image i take 2 shots at different exposures,mixed up with it.

[Walter Schulz]

? Please rephrase.

[togger]

I am saying i am not sure how to use the dual iso thing do i take one shot or 2 shots.

[Walter Schulz]

http://www.magiclantern.fm/forum/index.php?topic=7139.0

[garry23]

@togger

The Dual ISO feature applies to a single  image.

Having set dual to, say, 3Ev, you then set your exposure, I personally use ETTR, then take your picture.

The dual changes the ISO of every other two lines on the sensor.

You must post process a dual first. One way to look at this is that you will create a new 16-bit tiff digital neg.

So you are taking two brackets BUT interlaced on one image and bracketing with ISO, so your shutter speed is fixed.

You may find a few friends hints on my blog at photography.grayheron.net.

[togger]

Dual-ISO video not available on 7D yet.
Well i don,t see a lot of use for me then.

[togger]

Just removed ML from my canon 7D as i wanted the dual iso,but it does not work on it.

[Walter Schulz]

? It's working here and elsewhere.

[togger]

Well maybe i just can,t get it going on my 7D,but thanks anyway.
Now back with my 2.0.5 firmware.

[garry23]

@togger

It's your choice if you load/use ML. All I will say, as a photographer, ML has some killer features. The three that are at the top are : RAW ETTR, Dual-ISO and Auto- bracketing based on a RAW histogram.

Factor in an intervalometer and a ND 'calculator', and you have in ML the ideal 'travel light' capability.

I admit to not being a videographer, but this part of ML enhances your EOS even further.

One thing I will say is that ML initially can appear confusing and intimidating, especially if you are still learning to use your DSLR. So, IMHO, you should become confident with your DSLR and understand the basic technology of DSLRs first, before seeking out ML.

BTW here are a few snaps I took last week mainly using ETRR+Dual-ISO workflow: http://grayheron.smugmug.com/Catalina-Snaps/

Bottom line: by all means take a rest from trying ML, but don't give up 

Cheers

[togger]

I have been using cameras for years now,so i am very comfortable with mine,just can,t get this ML to work on mine,i know it,s me but hey ho,cheers anyway.

[togger]

Ok i am going to re-install ML & give it another try,this cr2hdr file,what do you do with this file,where do you put it,thanks.
Where can i find help on how this should be setup on my 7D,i don,t use video just stills.

[Walter Schulz]

http://www.magiclantern.fm/forum/index.php?board=56.0
And of course (and for the third time):
http://www.magiclantern.fm/forum/index.php?topic=7139.0

[togger]

Cheers,i will also search out youtube for tutorials on setting up the camera how it should be.

[Walter Schulz]

If you found a way to tell outdated/shitty Youtube tutorials from those actually and properly covering the newest developments: Please tell me.

[garry23]

@togger

As Walter implies, the info on Dual is there.

Also, as I hinted at above, you may find some useful info in my blog : eg http://photography.grayheron.net/2014/07/consolidation-series-part-2.html.

Hope your experiments go well.

Cheers

[togger]

Cheers guys.

[togger]

Ok i will try it this way,i am happy that i can install the firmware & ML on my 7D,what i am trying to find is what to do with the file cr2hdr that i d/loaded.
I have looked at all the links but i just can,t get this in my head,inside that file there are 3 others cr2hdr.exe dcraw.exe exiftool.exe
If someone could just tell me where these go instead of just pointing to links i might understand it a bit better,thanks.
I can use a camera but i am not a computer geek.

[walter_schulz]

Create a directory. Expand the zip and copy contents there. Drag and drop your CR2-file onto cr2hdr.exe.
If you use Lightroom you may want to install the plug-in.

[togger]

Thanks for that,now i get it,but the one thing i don,t see here is a plugin,i have tried putting these file into LR5 as well but isn,t working,obviously something i am doing wrong,don,t know,might give up.

[walter_schulz]

I don't know if you give up, but I'm tired of this. Garry, your turn.

[extremelypoorfilmaker]

Togger, if i may, why do you need dual iso, anyway? Maybe i might be wrong, but logic since now has always told me that as long as you can keep your iso not exceeding 1600 the footage it should be pretty usable anyway! Than, some cameras have better noise reduction that other ( see the 5D mkII vs the 6D ) and some other cameras they were built for night shooting ( Sony A7 )

I am just assuming you want Dual-ISO for a cleaner footage, right?

[togger]

Well if your tired of it then i will just leave it alone then.

[garry23]

@togger

The link I directed to on my blog takes you through what to do for single image Dual, ie not video stuff, ie the other .exe files are needed by cr2hdr.exe.

Also the first page of the ML plug-in post tells you in simple terms what to do, ie how to get it running in LR.

I'm afraid, at a distance, I can't help you anymore.

Good luck :-)

Garry

[DeafEyeJedi]

@togger --

Dual ios works well w 7D that I use at work... Just the video part isn't implemented yet.

Just photos and works flawlessly... Totally stunning and absolutely worth the post work!

Don't give up and unlike most of us here... Practice makes perfect and if we didn't give up then you shouldn't as well!

Keep it up and good luck!

[togger]

Ok,have been trying with this again,i don,t use video so this is just for photos,i re-d/loaded all the software & installed it again,the LR plugin is showing now.
Maybe it was corrupt in the last d/load i don,t know,but now it is all installed properly.
I have read that the dual iso only works on every alternate shot,so that means i have to take 2 shots of the same scene & use the second shot to work on dual iso,have i got that correct.

[garry23]

@togger

Dual-ISO taking is selectable and there are two strategies.

You can selected it to take a dual every time you capture an image.

You can also select it to take a dual every other click of the shutter, so you need to take two images of a scene to stay in sync. I don't use this option.

It's your choice and selectable in the menu.

Cheers

[togger]

Thanks for that got that bit now
So anyway i went out just local paths & woods,all the dual iso shots are showing pink in them,but i also had a polarizer on so i don,t know if that caused it or not.

[garry23]

@togger

An unprocessed dual will look strange, so ignore viewing at this stage.

You need to process it into a tiff first.

As I said above, try this workflow : ETTR to get the optimum exposure, ie tonal data, and use dual to cover the darks and shadows.

Cheers

Garry

[togger]

Even processed they were pink in the sky,i am using ETTR,i will have another play with it maybe.

[Audionut]

Upload an example please.

[togger]

Sorry i deleted them all,could it be because i had a polarizer fitted?.

[Audionut]

She might know.  I need the actual files to make an determination.

[togger]

  I will try & take some more shots later

[togger]

I took 2 shots second shot the shutter changed to 1/8000 & i don,t know why




The noise is bad as well

[togger]

Removed ML for now,maybe try again at some point.