Recent Posts

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1
HDR and Dual ISO Postprocessing / Re: cr2hdr for macOS Sierra
« Last post by Danne on Today at 06:56:23 AM »
New version up. Download in first post.
- Added support for RAWC metadata in mlv_dump.
- Removed hardcoded temporary fix

More about RAWC here
http://www.magiclantern.fm/forum/index.php?topic=17021.msg181639#msg181639

@adrjork
At some point premiere wouldn,t work with 14bit files but with 16bit I think. There are other reasons as well I,m sure. As long as the cdng tags are represented 14bit works just fine.
About white level and resolve. Maximum white point 14bit is 16383 and that is what 5D mark III is set to and this usually is good for bringing home most highlight information. This could however affect how highlights are handled in resolve. especially if adding different highlight recovery methods. If this seems to be looking strange you could try setting white level to 15000 in mlv_dump settings instead.

2
General Chat / Re: resolution interpolation to reach higher iso
« Last post by SpcCb on Today at 04:57:54 AM »
Binning is simply blurring followed by downsampling (reducing the resolution by dropping pixels).

Example on how 5D3 does 3x3 binning to get 1080p Bayer raw from a full-res Bayer matrix:
Code: [Select]
function im = bin_pixels_3x3(im)

f = 1/9 * ...
[
    1 0 1 0 1;
    0 0 0 0 0;
    1 0 1 0 1;
    0 0 0 0 0;
    1 0 1 0 1;
];

imf = imfilter(im, f);
im = imf(1:3:end, 1:3:end);

First step is a 3x3 blur (averaging) on each Bayer channel, second step is keeping the central pixel from each 3x3 block (after filtering).

Also FYI, on Canon DSLRs, pixel binning is done by hardware (analog electronics), not firmware.

Reference: http://magiclantern.fm/forum/index.php?topic=16516.0
Sorry, I use to split both method in my work because averaging or binning, it's not the same thing for me.
Sort explanation -> http://harvestimaging.com/blog/?p=1560
As you spoke of binning in some camera I thought it was binning _I mean pixel signal addition_ (was there a square root f(px-nbr) noise reduction when you made tests about that last year?), but if you say it's averaging, it's not binning. Or this is not clear.
It makes me thinking what is doing the averaging.. ??? Maybe it will be interesting to see the source code of the firmware function? Or the source code of the ASIC||FPGA who does it?
3
General Chat / Re: resolution interpolation to reach higher iso
« Last post by mothaibaphoto on Today at 04:06:46 AM »
Great new article on high ISO and Noise:
https://petapixel.com/2017/03/22/find-best-iso-astrophotography-dynamic-range-noise/
nothing really new, but worth read.
4
General Chat / Re: resolution interpolation to reach higher iso
« Last post by a1ex on Today at 02:20:37 AM »
Binning is simply blurring followed by downsampling (reducing the resolution by dropping pixels).

Example on how 5D3 does 3x3 binning to get 1080p Bayer raw from a full-res Bayer matrix:
Code: [Select]
function im = bin_pixels_3x3(im)

f = 1/9 * ...
[
    1 0 1 0 1;
    0 0 0 0 0;
    1 0 1 0 1;
    0 0 0 0 0;
    1 0 1 0 1;
];

imf = imfilter(im, f);
im = imf(1:3:end, 1:3:end);

First step is a 3x3 blur (averaging) on each Bayer channel, second step is keeping the central pixel from each 3x3 block (after filtering).

Also FYI, on Canon DSLRs, pixel binning is done by hardware (analog electronics), not firmware.

Reference: http://magiclantern.fm/forum/index.php?topic=16516.0
5
General Chat / Re: resolution interpolation to reach higher iso
« Last post by SpcCb on Today at 02:04:01 AM »
Yes. In post, simply apply a blur to your image. You will reduce noise at the expense of resolution (that's basically what pixel binning is).
(...)
I'm not so agree with that :)
Blurring pixels is far to binning pixels: for example you loose the level gain and so the SNR gain at same level.
6
General Chat / Re: resolution interpolation to reach higher iso
« Last post by SpcCb on Today at 01:58:54 AM »
Hello ΓΝ,

It's already done by some Canon cameras (like the 5D3) by the stock firmware (internal). See for << pixel binning >>.
You can also do it in post processing, several softwares can do it, even photoshop (menu filter>divers>other by using matrix convolution).
Best results will be with a RAW source image, of course (because of debayering).

Have fun ;)


Edit: Harf! dmilligan was first :D
7
General Chat / Re: resolution interpolation to reach higher iso
« Last post by dmilligan on Today at 01:51:57 AM »
in post processing (on raw, perhaps on jpg ?) to use interpolation (merge adjacent pixel or better interpolation) to simulate higher iso / longer exposure by lowering resolution ?
Yes. In post, simply apply a blur to your image. You will reduce noise at the expense of resolution (that's basically what pixel binning is).

Of course most people want to reduce noise without sacrificing resolution. There are various noise reduction algorithms out there that attempt this with varying degrees of usually very limited success.
8
General Help Q&A / Re: Precise Timing of rapid fire external trigger
« Last post by a1ex on Today at 01:44:06 AM »
Not with current implementation, unfortunately.

You can lift the mirror and keep it lifted with a piece of tape; however, the mechanical shutter is actuated. This part happens on a different CPU that is not very well understood (the MPU). You can take pictures with shutter open (see FRSP), but has a gradient at short exposures. Additionally, file saving and image capturing must be pipelined to achieve 4 fps.

If resolution and rolling shutter are not an issue, you could look into half-shutter triggers for raw recording. However, its timing is given by the LiveView clock, not by the external trigger.

Delaying pictures in regular burst mode using an external signal might be easy to implement (didn't try, but I don't see why it wouldn't work). Not sure if half-shutter can be used as a sync signal though, as it must be pressed to keep the burst running.
9
Raw Video / Re: Crop Mode not Always good Please make it optional
« Last post by dmilligan on Today at 01:40:10 AM »
I think maybe what OP is talking about is that if you use a lower resolution than the max of the current video mode, you get a crop instead of a downscaling. Though I'm just guessing, OP has not made it very clear what he is talking about, as there's something else called "crop mode", there's a "crop hack" on some cameras and there's now a "crop_rec.mo".

If that is indeed what OP is talking about, then his request is impossible. The only way to reduce resolution is by cropping. Rescaling involves either interpolation (which is too complex/intensive to perform in realtime on a dinky ARM CPU, and wouldn't work well due to the nature of raw Bauer CFA data), or line skipping/binning (which only allows certain specific multiples of resolution reduction, i.e. 1:3, 1:5, 1:7, etc, again due the Bayer CFA, unless you don't care about not having either a red or a blue channel). You can control the line skipping/binning factor by changing the Canon video mode or with the new crop_rec.mo
10
simply CROP wont get the point i guess due to the binning info, same for BINN(ing)
SMPL(ling) looks a bit hmm mismatching, sounds like audio stuff.
SENS(or) could be a candidate, but then i'd embed bayer pattern info and e.g. a pixel scan order (why not?), maybe same for TOPO
maybe ARCH(itecture) for sensor/scanning architecture info or SCAN?
CAPA (capture area), REGN (region) or SATT (sensor/scanning attributes) no SCAT please
CAPI for capture info also looks okay to me

if you fall in love with one of those, good. if not, fine as well :)
better thinking a bit too long about names than later being mad because it was misleading :D
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