PetaPixel

New Magic Lantern Improvement Adds 3 Stops of Dynamic Range to 5DIII and 7D

dualiso1

All of the updates coming out of Magic Lantern’s camp recently have been RAW video related. And while there has been news enough on that front to keep us excited, we were happy to see something new coming from the ML team today.

Dubbed Dual ISO, Magic Lantern’s Alex (a1ex) has unlocked three full stops of dynamic range that the Canon 5D Mark III and 7D sensors couldn’t previously take advantage of. That brings total dynamic range to about 14 stops.

The details are technical — if you want to get into the nitty gritty, a1ex has prepared an in-depth PDF for you here — but the gist is that your sensor can, in fact, sample half of the lines at ISO 100 and the other half at ISO 1600 (or higher) at the same time.

The photo above shows the difference this makes. On the bottom left you see the photo taken at ISO 100, while the top right shows same shot taken using the ISO 100/1600 combination method (high-res version here).

Here’s another sample shot, this one taken entirely with the ISO 100/1600 configuration (pixel peepers can check out a high-res version here):

dualiso

The reason this is only possible on the two cameras mentioned is hardware related. The 5D Mark III and 7D both have two ISO amplifiers. The chip that samples the image from the sensor is set via firmware to sample the same ISO from all the lines. The hack allows it to sample half of them at one ISO and the other half at another.

For the 7D, this function only extends to taking photos. The 5D Mark III, on the other hand, can also take advantage of Dual ISO in video mode, assuming you have yours equipped with the ML ability to take RAW video.

Of course, the improvement doesn’t come without pitfalls. You’ll get half-resolution in highlights and shadows in addition to some aliasing and moire in the same areas. You also lose the ability to critical focus when zooming in.

But if none of that seems like too big a price to pay, you can learn more about the tech by checking out the aforementioned PDF or visiting the original forum post where a1ex has kindly provided the code.

(via planet5D)


Image credits: Photographs by Luke Neumann.


 
  • http://www.purseblog.com/ Vlad Dusil

    h4x ftw. I am surprised that Canon has taken such a leisurely attitude with the firmware hacks… last I heard they were okay with their firmware being messed with unless it was the top range of cameras (1DX, C1/300 series).

  • Random Dude

    Still, even if I mess with the firmware, I bought the camera, I can do whatever I want with her. They don’t sell the firmware upgrade, so Canon can’t do anything against MagicLantern. They said that they don’t want their firmware being messed with, but legaly, no one can stop it.

  • Guest

    why add this to the 7D and not 5DII ? D:

  • https://twitter.com/adamhowardcross Adam Cross

    all you seem to get is extra noise – not something the 7D really needs :P

    ps. since you’ve all misunderstood me, I’ll clarify what I mean – look at the high res image of the 2nd sample – it’s incredibly noisy, I’m not talking about the bottom half of the split image (you guys seriously thought that was what I was referring to? oh dear.)

  • Chris

    Of course they can, they are Canon chips with Canon firmware on them, legally they can put a stop to all of this, they own the code.

  • Joey Duncan

    They can, Apple of a good example of what happens when big companies flex their muscles. If Canon wanted to put a stop to it, they could. Time and time again stuff like this has been shut down.

  • Chris

    Because the 5D II doesn’t have two ISO amplifiers like the 7D and Mk III, as the article states.

  • Joey Duncan

    I don’t think I understand what you are trying to say here.

  • Chris

    The noise on the bottom left is underexposed at ISO 100 pulled to a correct exposure, the top right is the ISO 100/1600 pulled to a correct exposure. It’s also a video still.

  • Chris

    I think you missed the entire split-screen of that top picture; the bottom is before, the top after. If that’s “added noise” to you, then there is no solution that would satisfy you.

  • https://twitter.com/adamhowardcross Adam Cross

    no, I didn’t miss it, I looked at the high res version of the 2nd image.

  • https://twitter.com/adamhowardcross Adam Cross

    well, the 7D is noisy enough – adding this will just make it worse. the high res 2nd image looks awful.

  • Chris

    Yeah, and then they would lose massively in sales to Nikon; as some of the ML features are baseline features in Nikon (intervalometer, etc), and others, like RAW video, make Canon a step ahead.

    Kind of a brilliant gift really, it costs Canon nothing to develop, and they reap the benefit. And they’ve already said if you brick your camera as a result of it, it’s not a warranty fix.

  • https://twitter.com/adamhowardcross Adam Cross

    “On the bottom left you see the photo taken at ISO 100″ according to the article it’s a photo, not a video still. look at the high res version of the 2nd image, it’s incredibly noisy

  • Chris

    If you look on the ML post on the forum, (I assume we are talking about the Batman pic) it says it’s a still from video.

  • https://twitter.com/adamhowardcross Adam Cross

    I think DL Cade needs to clarify that it’s a video still – but that doesn’t take away from that 2nd image which isn’t exactly impressive.

  • T-Dawg

    Adam, download the DNG, then you’ll understand.

    I thought the same at first, and then I downloaded the DNG to see what was going on…. clearly a dramatic improvement in dynamic range.

  • Chris

    If you mean the orange carton pic, I’d take noise in spades to get that extra few stops. It looks extremely well controlled to my eye.

  • Matthew Wagg

    That is seriously amazing. If only Canon could have thought about it, they could have got us all buying new cameras to take advantage of this, instead I now want a 5dmk3 with Magic Lantern. Oh wait, Canon wins both ways ;) Seriously ML guys are technowizards of the highest order.

  • https://twitter.com/adamhowardcross Adam Cross

    tried the DNG link but all i’m looking at is the Quicktime logo, I downloaded the original .CR2 file and opened it up in Lightroom and it looks just the same as the sample above but I zoom in and all I can see is light and dark banding across the whole image…. which is really weird, due to the interlacing of separate ISOs no doubt? not very helpful if you want to see magnified detail for editing, or is it just something with this sample? who knows. .

  • Chris

    I think I know what you mean, that’s just Canon. I’ve never seen that sort of cross hatching on Nikon sensors, but Canon is a wee bit lacking in the dynamic range department, and the side effect of boosting a few stops is obviously light cross hatching. Still, if it’s only really visible at 1:1, it’s not too worrying to me.

  • Chris

    Nope, that’s someone else. My response is along the lines as the other Chris; there is some blotchiness, but its also early in the dev. Early RAW video could do 50 frames at <1080, now they have 1080p running continuously.

    If you're shooting anything with motion (say add a model to that carton shot or a sink with running water) then not having to do frame blending is invaluable to keeping resolution and avoiding artifacts. As they point out in their posts, it's not something you'll use for every shot. But the times you'll use it, you simply can't accomplish it as well with the Canon sensors as they are

  • Chris

    Of course, I wasn’t disputing any of that. :-)

  • https://twitter.com/adamhowardcross Adam Cross

    I think it’s just something with this particular file, I don’t know – the 1:1 examples on the ML psd show it how it should look, this is what I see in Lightroom when I magnify the downloaded CR2 file

  • https://twitter.com/adamhowardcross Adam Cross

    don’t worry, Chris! I didn’t think it was you – he’s/she’s just posted a bunch of stuff on all of my replies, just used this one to reply to him/her.

    Coming from a stills point of view (I haven’t shot very much video at all) that 2nd image which is a single shot from the 5D mark III is just too noisy for me, it looks like a regular shot with the shadows brought up too much making the noise way too obvious – the combination of 100 and 1600 just doesn’t look like much of an improvement – if it is early in development then fine, i’ll wait to see what happens. But, again, from a stills point of view, varying the shutter speed between shots and keeping ISO low, blending the shots afterward would yield better results (but that’s just the norm for any HDR stuff)

  • Banan Tarr

    Obviously an improvement but I wonder about overall noise. If half of the image is coming in at 1600 then you are definitely going to get more noise than ISO 100. So the useful point of this is when you REALLY need that extra dynamic range vs. a little bit of extra sensor noise?

    In which case I’d usually just bracket two shots and combine in post at ISO 100.

    In which case this is really useful for 2 things: moving scenes and video.

    Pretty cool stuff!

  • Jared Monkman

    I don’t see the noise you’re complaining about

  • Ian

    I’m not getting this at all. If that’s ISO 100 (bottom part of the top photo), it’s been underexposed several stops and then pushed several stops, and it’s likely a JPEG or unprocessed RAW. I wouldn’t really say this is a fair comparison if the file was exposed “to the left” like that.

    If that’s not the case, that’s one defective piece of crap 5D Mk III because even my old 1999 Kodak DC280 was better than that at ISO100.

  • tarena1991

    or you can get a D800 and get 14 stops right out of the box…

  • Peng Tuck Kwok

    It’s not a hack as in they took Canon’s source code used it, they’re just using Canon’s API and SDK (which are documented) to do all of this.

    Yes they can legally stop it if they want no disputes.

  • tarena1991

    for less money …

  • https://twitter.com/adamhowardcross Adam Cross

    you only have to look at the high res image and magnify 100% look at the dark and shadowed areas, it’s obvious?

  • Cute D4 Shooter

    14 stops of detail smearing and never able to shoot full sized NEFs (or even half sized NEFs) for doing big jobs like sports events or weddings. Yeah, the cost of the D800 reflects itself after buying 128GB cards, and new hard drives to keep up. Definitely not cheaper by any stretch of the imagination.

  • William Zhang

    That’s exactly the point. If you want to keep any highlight detail in a high dynamic range scene like this, you will have to under-expose for several stops. This works as a one shot HDR, odd line exposes the scene at ISO 100 so highlight detail are kept but shadow are crushed. even line exposes the scene at ISO 1600 so shadow details are kept but highlight are completely blown out. You then post-process to bring best of both worlds, at the cost of losing almost half of vertical resolution. It’s as simple as that.

    Anyone who is not impressed, try to shoot in the same condition: dark room with window light showing outside scene. See if you can do any better in conventional ways

  • tarena1991

    well, if you’re trying to do serious event photography with a D800, you might as well be using an 8×10 view camera to shoot the shuttle launch. there’s a reason for the D4 and it seems like you’re aware of it.

  • Chris

    That’s definitely not right! How odd.

  • Chris

    On my Nexus 7 I am seeing the same thing from the .CR2, but not when viewed from my laptop, although not as extreme as you see. Strange.

  • Luke Daniel Neumann

    I took the pic. The original CR2 files come out like that, you need to process them in order to actually get the extra dynamic range. What you are looking at in the original CR2 is lines of pixels with differing ISO values, hence the strange effect.

  • Chris

    How on earth can you process separate lines of pixels to pull them in line with the others to make a balanced shot?

  • zaakir

    if you think the 7D is noisy, youre spoiled and have probably never shot film in your life lol.

  • Luke Daniel Neumann

    That is something I can’t answer. I just do some testing for Magic Lantern, they brew the sauces. You run an .exe file similar to the one used to process the raw video.

  • unimpressed

    I have never seen noise like the bottom right of the top picture at 100iso on any decent camera, this looks like it is either bullsh%t or a waste of time or both.

  • Marco

    D600 then. Still 14 stops, smaller files and even less money.

  • Chris

    Thanks for the insight, Luke. :-)

  • https://twitter.com/adamhowardcross Adam Cross

    i’ve shot plenty of film (haven’t been shooting digital for very long), film grain has a completely different aesthetic to digital noise – film grain can look good, digital noise never looks good unless the noise is the point of what you’re doing

  • http://www.picxel.dk/ Stef G / Picxel

    That’s an odd way of telling everyone that you did not read and/or understand the article.

    Btw. which part of your comment is not either bullsh%t or a waste of time?

  • Please, be realistic

    The D800 is not exactly known for detail smearing, but if you insist you can also get a K-5, D7000, D7100, D5200. All with 14 stops of DR and fantastic features.

  • install

    how do you install it on 7D? any tips?

  • Chris

    It is purposely under exposed and corrected in post to make a balanced picture. Of course it looks like s**t, God knows how many stops it was underexposed when shot.

  • Chris

    Try actually reading the article and following the links…