Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - michael84

Pages: [1]
Post-processing Workflow / From CR2 or DNG to MLV?
« on: January 29, 2019, 11:16:38 AM »
I am wondering wether it is possible to convert CR2 odr DNG pictures back to MLV? I would like to try darkframe subtraction on regular pictures, but so far the only way to do this seems to be using Rawtherapee, however, i would rather use Adobe Lightroom. Also, i would need to average dakrframes taken in photo mode, which cannot be done by MLV dump. My idea would be to take my CR2 files, convert them to DNG with the Adobe converter, make an MLV file out of DNGs photographed with the same settings (shutter speed, ISO, same event) and subtract a matching averaged darkframe from this MLV, then export back to DNGs, which would be edited as usual in Lightroom.

In short - use the same workflow possible now with MLVs also for stills. Capturing to MLV via fullres silent pics is not feasible for most of my work, since i cannot use a flash in this mode.

Would it be possible to have a "reverse mlv_dump", which takes DNGs und makes an MLV out of them?

I have a problem with the current iso_regs module in the 4k crop_rec build. I can only adjust the ADTG gain in very coarse steps (100 or 200), an the ADTG preamp in steps of five until i am below 30 or so. Is this a bug, or do i do something wrong? I did not have these problems with older builds.

ML ISOs tend to reduce what i recall i called "amplifier glow" (magenta-like glow in the shadows, visible when pushing high ISOs and/or in long exposures). Especially the preamp seems to be the major contributor here. I tried various settings starting from Canon ISO 200, from ADTG only (reduced until WL drop), to 0xFE gain 0 and preamp standard, to 0xFE 0 and pregain 1. Only lowering the pregain reduces the glow significantly.

Only ADTG:

Only 0xFE:

0xFE=0 and pregain 1:

At high ISOs, ML ISO settings tend to clean up the colors a bit, and move the a bit toward green (presumably because the amp glow is reduced):

ISO 3200, Canon:

ISO 3200, ML (pulled from 6400):

Now lets push the exposure a little bit:



BTW, is there any way to convert a DNG to ML RAW video or MLV? So that i could try the vertical stripes fix from MLV Mystic to reduce the banding noise?

Yes, this was pulled from Canon ISO 200.

Screenshot - had to reproduce settings, because i forgot to take one:

raw_diag Canon ISO:
raw_diag ML ISO:

Next tests coming: ISO 200, 400, 800 and 1600 with flash illumination, long nighttime exposures, and high ISO (3200 and 6400) with typical exposure times needed to freeze motion, e.g. 1/400 to 1/1000.

A quick test with a high DR scene that would require dual iso, or exposure bracketing HDR, or a flash. One Picture was taken with Canon ISO 100, 1/125 s shutter and f8. Second exposure was taken with ML ISO 100 (actually 119 reported by iso_regs), ADTG gain at 962 (-0.16 EV as reported by iso_regs), preamp at 1, 0xfe at 3, same exposure as with Canon ISO 100.

Both raws loaded in Lightroom 6.6, exposure pushed by almost 4 stops (+3.74 EV on ML ISO one, +3.84 on Canon ISO) to bring out the shadows, highlights at -100, WB as shot. ML ISO visibly reduces color noise and the purple shadow color shift i get when i push them too much from Canon ISO. Luma noise is also reduced and looks finer, which helps to preserve details. Only the banding noise seems to remain. Color noise reduction in Lightroom was left at standard (25), even bringing this one to 100 on the Canon ISO picture could not bring it to a comüparable level to the ML one.

Now if there is a fix for the banding noise....

Full Size JPEG, Canon ISO 100:
Full Size JPEG, ML ISO:

Crop 1, Canon ISO:
Crop 1, ML ISO:

Crop 2, Canon ISO:
Crop 2, ML ISO

Crop 3, Canon ISO:
Crop 3, ML ISO:

Crop 4, Canon ISO:
Crop 4, ML ISO:

Crop 5, Canon ISO:
Crop 5, ML ISO:

Now i need to learn how to use cmos_log to apply the CMOS patch.

I spent the last days learning how to compile ML to use these tweaks on my 5D MK III. On the weekend i decided to give the ISO REGS module a go and used ISO 860 (pulled from 1600) and ISO 3400 (pulled from 6400) for some scenes which are typically troublesome because of the extreme dynamic range involved like harsh stage lighting and a subject sitting in the sun with a dark wooden wall behind him.

Exposure was set at +2/3 EV from the correct value for unmodified ISO. Shadow/midtone noise is clearly better. I need to post some crops tomorrow, i also shot some test images of real world scenes.

Just one question - i do not really get what "CMOS patched" means? As far as i understand, this is some tweak which has to be applied with ADTG GUI, and cannot be done with ISO REGS, right? Can i use ADTG GUI to apply the CMOS patch, and then use ISO REGS to set the rest?

Tested the new mlv.rec with my 7D, i can now record past 1 minute without frame drops. This time, sync was off by 2 frames, the audio was 2 frames before the picture, while the audio start (waveform peak) appeared to be 3-4 frames late. Now i will try again using the old mlv.rec, to see wether the sync issue is caused by the new mvl.rec, or just some inconsistency by the camera.

hmm i have read reports that said their audio start is 2-3 frames off.
so you are sure that the audio is perfectly in sync on 7d?

At least so far i can tell with my method. I fired an EX-430 remotely while recording, and looked frame by frame wether the Flash in the picture lined up with the discharge pop in the audio track. Every time it matched exactly. So unless the pop and the visual flash did not occur at the same time (will check this later with my HDR-FX1, just to be sure), the sync has to be ok, otherwise i would certainly be able to see it. Flash duration is only one frame. There is no sync drift over 1 minute recording.

However, what does happen is that the first few frames (2-3 could be just right) are not usable due to some kind of high level noise (waveform starts with a spike then drops to normal level). This is consistent through multiple recordings. So no offset, but some few frames of unusable audio. Note that this observation is only for 25p (selected in Canon menu /with and without 25 fps override selected, not 24p test yet), so for other modes there might be an offset/sync error.

I will try the experimental mlv.rec later. Amazing to see how much progress has been made recently, with updates rolling in on a daily basis. Keep up the good work!

Did some further tests with Sound recording on the 7D, this time with an external mic plugged in. So far, i can get continous recording at 1728x972 and 25 fps. When i reach 1 minute, the buffer suddenly begins to fill, and the recording stops at around 1:03 to 1:04 each time (no skip allowed). This coincides with reaching the 4 GB limit and file splitting. Either my card is too slow to catch up after the momentary writing speed drop at file split, or there is still the same bug others have been reporting.

Both with and without fps override (set at 25 fps exact) the timebase of the video is 100% correct compared to a clock, at least for the 1 minute+few seconds intervall i am able to record. I imported the files in Resolve lite, and set the project at 25 fps. No worries here.

The audio is perfectly in sync, both checked against the ticking of the clock an several flashes fired next to the mic throughout the recording. I got only one video with a 6 second longer audio file than the video, this was one i recorded until the camera stopped. The other files, where i stopped just before the buffer was full, i only get a few frames to much audio. Because the sync is ok, i guess the audio recording does not stop exactly simultaneous with the video. However, compared to the hassle external sound recording witout any in camera audio for easy matching in post, i can perfectly live with that little imperfection.

Now i need to develop a workflow, i guess i will try a conversion in ACR with the VisionLog Profile into DNxHD 10 bit, and grade the footage in AE or Premiere, perhaps using VisionLog LUTs. My machine is too slow to work directly with DNGs, and i want to use ACR for conversion, as Resolve Lite has no noise reduction and feels rather non intuitive to work with. Too bad that ACR has these flicker issues, it would be easy to get a nice look in it quickly, without having to use any LUTs later.

Next thing to test will be the 24p mode, although i probably wont use it here anyway. In PAL land, 25p is the way to go, i think, unless you plan to print your work to cine film.

It seems that MLV.SND is finally working on the 7D. I just recorded 4 short Clips, all 4 MLVs extracted with MLVBrowseSharp in DNGs and WAV - and got 4 WAV files, each of them containing usable Sound.

My Settings:

1) For the first two files:
Sound Record: Normal
Beep, test tones: OFF
MLV Sound: ON
other Settings Default, Sound in Canon Menu on AUTO

2) Fot the other two files
Sound Record: Separate WAV
Analog Gain: 26 db
Rest unchanged

Tested with a quick DNG->JPEG convert in Lightroom and importing in Premiere, the Audio is 7 Frames longer than the Video at 25 fps (no FPS override, Canon Video set to 25p and PAL). If i Interpret the sequence as 24p, the Audio is 5 Frames too short.

Next things to test will be wether i can get continuous recording with MLV Sound on, and wether the audio stays in sync. I will shoot an analog clock with audible ticking for a Minute or two and use a flash at intervalls for easy sync checking and in case the ticking is not loud enough. This should also help to check the video timebase - perhaps i need to use fps override to get exact 25p.

Currently, the write performance lags a bit whena recording is started, display shows 200-300 Frames expected, but then catches up at up to 80 MB/s, the buffer graph goes down, and the writing Speed settles at about 70 MB/s. My card is a Transcend 64 GB, it definitely needs low Level formatting with autoformat, otherwise it really struggles to reach the necessary writing speed. buffer fill method is set at 4, extra hacks on. I did not test other settings, maybee i should to find out what works best.

Global draw and Digic Peaking are on, also the  Histogram.

Pages: [1]