Messages

16

Chronos User Discussion / Re: Filming Rocket Testing - settings advice welcome.

« on: October 05, 2021, 08:02:44 AM »

According to the spec sheet, the Chronos 1.4 can record with a shutter speed of up to 1/1000000s.  That is very different from the frame rate.  You would set the desired resolution and frame rate, then adjust the shutter angle to achieve these super fast shutter speeds.  The faster the shutter, the less light is available for exposure.

That being said, I really doubt you'll need to worry about adding ND filters to lower the amount of light hitting the sensor.  Although if you really want to go that route, it should be easy to add these kinds of physical ND filters to any kind of lens you are using.  At the very extreme, you could even mount the camera behind something like a welder's shield. 

I would recommend just playing with the shutter angle and that will most likely get a nice exposure even with a very bright source like a rocket.

If you're not familiar with how shutter angle works, 360 deg is "wide open" and that means, say you are shooting at 1000 fps, your shutter speed will be 1/1000s.  General rule of thumb is to try for around 180 deg shutter for a "pleasing" amount of motion blur.  That means at 180 deg, it would mean 1/(360/180) * 1000 fps) or 1/2000s shutter speed.  Crank the angle down to 10 degrees for example and you'd be at 1/(360/10) * 1000 fps) or 1/36000s shutter speed.  A 1 degree shutter would mean 1/360000s shutter speed, etc.

17

Chronos User Discussion / Re: Footage feedback

« on: September 29, 2021, 09:38:11 AM »

1. can anybody tell me why my footage has that small amount of blinking in the colored area, especially in red?

2. Why did this rolling shutter happen?

Hi, I agree with Nikon1.  What you are seeing, especially with the fruit clip is just digital noise in the red channel probably from boosting the saturation a bit too much and it's getting blown out.  You have to be very careful with these cameras as they don't have the same dynamic range as you'd be used to with normal video cameras or DLSRs.  I would recommend shooting in Cinema DNG for best possible dynamic range and being careful not to blow out any of the colors in post.

FWIW, both the Chronos 1.4 and 2.1 use a global shutter sensor, so "rolling shutter" is not a possible artifact with these cameras. 

18

Software Dev / Re: Chronos V0.7.0 Full Release

« on: September 27, 2021, 09:07:23 AM »

Thank you mklinger for the help...

I'll buy a color calibration chart, I'll post here when it arrives...

Sounds good, I'm happy to help.  When you shoot the color chart, try to make it fill up a majority of the frame if possible.

19

Software Dev / Re: Chronos V0.7.0 Full Release

« on: September 27, 2021, 07:35:55 AM »

Thanks mklinger

I'll shoot this weekend and I'll report back!!

Hi muringuets, remember, this LUT was designed for the Chronos 2.1.  I think you mentioned you had a 1.4.  It may work well on those DNG files, but honestly, I doubt it...

Someone needs to do the same exercise with a 1.4 camera and 0.7 to provide a similar LUT.

I have the exact same "washed out" colours as your comparison image, figured I should try your LUT, I knew it probably would not work, but I tried anyway... As you might expect, results were not good...

Feeling a bit frustrated now, no matter how much I try, I can't bring the colors back on my footage, still washed out colours, otherwise too much green and too much red, no vibrance... Boy this is hard hehe

Rolling back to 0.6.0 until some LUTs surface, or at least until I can figure out how to properly extract the correct colors from the footage...

Do you have a color chart?  If you can shoot it with 5600K lights (or outside) as evenly as possible and as well exposed as possible, post the DNG and I'll see if I can create a LUT from it.

Also post a couple DNG images from actual shots you are trying to color correct so I can fine tune the LUT attempt if possible.

20

Software Dev / Re: Chronos V0.7.0 Full Release

« on: September 27, 2021, 07:31:50 AM »

Thanks mklinger

I'll shoot this weekend and I'll report back!!

Hi muringuets, remember, this LUT was designed for the Chronos 2.1.  I think you mentioned you had a 1.4.  It may work well on those DNG files, but honestly, I doubt it...

Someone needs to do the same exercise with a 1.4 camera and 0.7 to provide a similar LUT.

I have the exact same "washed out" colours as your comparison image, figured I should try your LUT, I knew it probably would not work, but I tried anyway... As you might expect, results were not good...

Feeling a bit frustrated now, no matter how much I try, I can't bring the colors back on my footage, still washed out colours, otherwise too much green and too much red, no vibrance... Boy this is hard hehe

Rolling back to 0.6.0 until some LUTs surface, or at least until I can figure out how to properly extract the correct colors from the footage...

Do you have a color chart?  If you can shoot it with 5600K lights (or outside) as evenly as possible and as well exposed as possible, post the DNG and I'll see if I can create a LUT from it.

21

Software Dev / Re: Chronos V0.7.0 Full Release

« on: September 22, 2021, 05:42:37 AM »

Thanks mklinger

I'll shoot this weekend and I'll report back!!

Hi muringuets, remember, this LUT was designed for the Chronos 2.1.  I think you mentioned you had a 1.4.  It may work well on those DNG files, but honestly, I doubt it...

Someone needs to do the same exercise with a 1.4 camera and 0.7 to provide a similar LUT.

22

Software Dev / Re: Chronos V0.7.0 Full Release

« on: September 21, 2021, 11:42:00 AM »

Hi everyone, 

I recently took the time to try and refine my Chronos 2.1 DaVinci Resolve LUT by lighting my color chart with 2 Godox VL300 5600K lights and spending some time to really dial in the colors and white balance.

I am pretty happy with the results and thought I'd share my LUT with the wider community if anyone would like to try it out.  It should be a decent starting point for indoor controlled lighting at 5600K or daylight shooting.

You can download the LUT here:

https://klingerphotography.com/Chronos21/Chronos21_v7_Release_5600K_v3.cube_2.frame.cube

I think all you need to do is drop it in your DaVinci Resolve LUT folder.  On my machine that is here:

C:\ProgramData\Blackmagic Design\DaVinci Resolve\Support\LUT


What the images below show are the before and after of the color chart under controlled lighting, and then just a quick outdoor shot under direct sunlight with the only correction being applying the attached LUT.

Hopefully this helps some folks out who are struggling to get decent color with Cinema DNG files from the Chronos 2.1.

I'm using the paid "Studio" version of Resolve.  I'm pretty sure this will work with the free version and probably with other NLE programs like Premiere, Final Cut, etc., but I haven't tried any of those packages.

Thanks!

Marc

23

Software Dev / Re: Chronos V0.7.0 Full Release

« on: September 09, 2021, 06:12:12 AM »

Hello and thanks for your replies. I fully understand the advantages of RAW over H264, that's not my problem. I am just wondering where the "default" look of the RAW is created.

Now if I get it right, the in camera color Matrix is applied to H264 only, right?

In DaVinci you have that color matching tool. With this you can film the color cards you bought for 200$ and then make DaVinci match the footage the color card. As shown here, right?

Now would it be possible to film the color card with a standard 5.600k light and then match this footage min DaVindi to the color card, and boom, one would have a sharable algorithm that could be posted here? This would at least give a good starting point, no?

Yes, exactly!  We are waiting for the Kron folks to create and share the "official" LUT.

I haven't had a chance to spend enough time with 0.7 yet to dial in a LUT with my 5600K lights, but I (or anyone) could certainly share DaVinci LUTs once created for a good starting point.  It's on my to-do list

24

Software Dev / Re: Chronos V0.7.0 Full Release

« on: September 09, 2021, 04:58:58 AM »

Very impressive! And very nice color!

Actually I don't understand how the color progress works. I wonder if a) the camera itself does have a LUT that is applied to the RAW internally or if b) the DNG really are absolutely unprocessed data and the LUT has to be applied in post?

If a): As the colors changed with the software version, there has to be some algorithm working in camera, right? If so: which? Is this the color Matrix?

If b): Does one have to develop sort of default setting for Adobe RAW or DaVinci then?

Sorry for these beginners questions, I never digged into all that...

Hi clkdiv,

I'm not 100% sure if DNG is completely unprocessed in the camera, but it certainly behaves similarly to Log and RAW formats from other video cameras which have very little or no processing.

The benefits of using DNG over H.264 are a higher color bit depth, meaning more color information is actually stored, which typically means more dynamic range is possible.  There are also no compression artifacts from the H.264 process itself, meaning you can wait until the very last step in your process to create a compressed video file for YouTube or whatever.  This is ideal if you do any post processing with the file.

Regarding your second question, yes, there really needs to be a default LUT that gets applied in post that goes from Cinema DNG to Rec709.  You need this LUT for every different lighting condition, but having a standard one for daylight would be very useful.  I suggested to the Kron folks that they publish a default LUT, and they are working towards that, but don't have one yet.  Having a proper color chart and some knowledge how to use it allows users to create these on their own and get really good results (like takashima's video above).

The general process is you shoot a video of just the color chart in your lighting conditions.  You color correct that video using a VectorScope (in software) based on the very objective "perfect" colors on the chart (which is why those charts cost $100+).  You then create a custom LUT that gets you the proper transformation in those conditions (this step is trivial in DaVinci Resolve).  Then, you can shoot anything else in those conditions and just apply that previous LUT and it'll get you there!

At this point, for 0.7 on a Chronos 2.1, if you don't have a color chart, I would probably stick to shooting H.264 for now - but even that needs some adjustment to get proper colors, but not nearly as much and you can get reasonable results with the basic adjustments like temp/tint/saturation.

25

Software Dev / Re: Chronos V0.7.0 Full Release

« on: September 09, 2021, 04:27:47 AM »

Hi, everyone.

I want to shoot with Cinema DNG with Chronos 2.1 Ver.0.7.0.
But I couldn't get the right color!
I searched for a solution for a while, finaly, I reached to the X-rite ColorChecker Passport 2.

https://www.youtube.com/watch?v=xL2BWQRJbv8&t
↑Sorry, this is japanese clip.

I hesitated to pay close to $ 200 for this color chart, but the results were very very good. I wanted this color! I was finally able to reach it.

https://www.youtube.com/watch?v=q-k7MYPWbIw&t
Thank you!

Hi Takashima, congratulations on your color results, they look fantastic! 

It was also difficult for me to initially justify the cost of a color chart, but it's really a necessary tool if you are serious about the final results.

I look forward to seeing more of your videos!

26

Software Dev / Re: Chronos V0.7.0 Full Release

« on: September 08, 2021, 07:13:05 AM »

I still think quality wise 0.6.0 was a little better, the DNGs are coming out with a lot of color noise, and a nasty pink/magenta tint that I did not have before...

One quick thing, double check that you updated all the way to version 0.7.  The pink/magenta cast was a big problem with 0.6 but I found it was pretty much completely fixed in 0.7 except for very high gain situations at low resolutions. 

If you were at version 0.5, I'm not sure if the camera would auto-update all the way to 0.7, or if you need to update to 0.6 first.  Anyway, before you pull your hair out too much, re-check the software version on the camera to make sure it is indeed 0.7 especially if you came from 0.5.

I need to check the release 0.7 in case they changed something drastic from the alpha 0.7 I was testing, but as you can see from this video, the pink cast was a major problem with v6 and almost completely fixed with v7 in my experience:

https://youtu.be/a4dAjT9dE0k

Hi mklinger, I did update correctly from 0.6.0 to 0.7.0, checked and it is working properly...

I watched your video about 0.7 alpha testing, and the other one you suggested about color correcting log videos. I'm new to this video editing and professional tools and stuff, I'd say I'm just used to the previous method of color correcting and editing videos. I own the 1.4 camera for about 2 years now, and it took me a while to get good results out of it, I was happy (not in the saving speed department, but it's okay), it's just another step that I'll have to conquer on this long learning curve, but I'll get there...

I have just one comment about all this, you're using the 2.1 camera, and I see a lot of posts around here where you guys have problems with this version (purple/magenta tint, lower resolutions problems, banding, etc), but I'd like to see some tests made on the 1.4 version, just to make sure the software is developing in a way older cameras are getting improved too, because if they don't, I might as well stay on and older software version...

Anyway, I understand the importance of this version, and the improvements you're getting on your camera, but comparing my footages on 0.6.0 and 0.7.0 I can't really see a lot of improvements, it's the other way around... And I say this mainly analising footage from open areas, without aditional lights, just regular sun light (perhaps too little lights, but that's what I have to work with)...

Anyway, seems like a good time to upgrade my camera...

Ahh, I didn't realize you were using a Chronos 1.4.  It's my understanding that that camera has not had nearly the same image quality issues as the 2.1, at least not since its early days.  The 2.1 has been almost unusable under certain conditions until this release, so it's a big deal for that camera.

I have no idea how 0.7 works compared to 0.6 on a Chronos 1.4.  There probably isn't much image quality difference as it was already really good, from the examples I see (I don't own one).  Maybe the biggest reason for you to upgrade would be the saving speed increase, but if you are happy with the earlier version work flow, it might not be worth it.

27

Software Dev / Re: Chronos V0.7.0 Full Release

« on: September 07, 2021, 04:32:02 AM »

Hello mklinger. I’ve followed your instructions and colour corrected 2 clips, the result is much better now than before! I was just doing quick tests, will dive in more deeply in the near future.

Your color corrected clips are looking good, nice job!!

28

Software Dev / Re: Chronos V0.7.0 Full Release

« on: September 06, 2021, 01:53:54 PM »

I still think quality wise 0.6.0 was a little better, the DNGs are coming out with a lot of color noise, and a nasty pink/magenta tint that I did not have before...

One quick thing, double check that you updated all the way to version 0.7.  The pink/magenta cast was a big problem with 0.6 but I found it was pretty much completely fixed in 0.7 except for very high gain situations at low resolutions. 

If you were at version 0.5, I'm not sure if the camera would auto-update all the way to 0.7, or if you need to update to 0.6 first.  Anyway, before you pull your hair out too much, re-check the software version on the camera to make sure it is indeed 0.7 especially if you came from 0.5.

I need to check the release 0.7 in case they changed something drastic from the alpha 0.7 I was testing, but as you can see from this video, the pink cast was a major problem with v6 and almost completely fixed with v7 in my experience:

https://youtu.be/a4dAjT9dE0k

29

Software Dev / Re: Chronos V0.7.0 Full Release

« on: September 06, 2021, 01:40:14 PM »

mklinger thanks for the input

It took me a while to fully understand the color correction, but after a lot of tweaking on Davinci Resolve, I got a usable sequence, but it is really really weird, counter intuitive and well it's hard to get it right. I still think quality wise 0.6.0 was a little better, the DNGs are coming out with a lot of color noise, and a nasty pink/magenta tint that I did not have before...

Anyway, I'm impressed with the speed improvement, but still need time to get the best out of this new DNG files, not happy with that for now...

Hi muringuets, once you have the color correction figured out for a given light source, you should be able to create your own LUT (look-up-table), and then just apply that to any new footage shot in the same conditions.  That is how the process is designed to work with a color chart, shoot once with it, in sunlight, or your artificial lights, etc., use a VectorScope (in software) to dial in objectively perfect colors, or as close as possible, save the LUT, and then you can apply that to future footage with no extra effort or ever having to shoot the color chart again in the same lighting conditions.

Sorry for the long-winded response if you already understand this process.

Basically, shooting in Cinema DNG on the Chronos is now even more like shooting in Log or other various Raw formats on conventional video cameras.  Usually, the camera supplier will provide a basic LUT to start with, which is what is missing for us (for now).  For example, Canon provides a Log2->Rec709 LUT, Log3->Rec709, etc.  It is very challenging to start from scratch if you don't really know what you're doing.  For example, adjusting just white balance, tint, color temp, and global saturation is not going to work.  Those adjustments are meant to tweak the final color look, but wont get you from Log (or Cinema DNG in our case), to Rec709.

I would say it would be almost impossible to get objectively correct colors from Cinema DNG without a color chart. 

I like using the X-Rite ColorChecker Video.  It looks like it's been discontinued, but there is a newly name-branded version coming soon:

https://www.bhphotovideo.com/c/replacement_for/1191325-REG/x_rite_msccvpr_colorchecker_video.html


You mentioned that you use DaVinci Resolve.  The process of creating custom LUTs is super easy in that environment.  You can right-click on a clip in the color correction tab and there is a "Generate LUT" option right there where you can create a custom LUT from your existing correction.  The Gerald Undone video I linked in an earlier post shows this in more detail.

FWIW, I do a lot of video work with not just the Chronos, but things like a Canon XF-705, and various DSLRs.  I waited WAY too long before I got a proper color calibration chart and learned how to use it.  It makes all the difference in the world!


 

30

Software Dev / Re: Chronos V0.7.0 Full Release

« on: September 06, 2021, 08:44:58 AM »

Hi guys,

I wasn't allowed to share my experience with the 0.7 version of the software before it was released, but now that it's out, I'm sure they won't mind me sharing my initial findings.

I haven't had the time yet to properly evaluate the release version of 0.7, but I did do some work helping the Kron folks evaluate an alpha version of the software and the color change with Cinema DNG was present there too.

Here is a link to a video showing my findings:

https://youtu.be/a4dAjT9dE0k

The short answer is that Cinema DNG can be color corrected properly with 0.7, but it's harder and you really need to use a color chart and know how to manipulate the hue/hue and hue/sat histograms using a VectorScope.

I would really recommend watching Gerald Undone's video on color correction, as this type of manipulation is required to get the best out of Cinema DNG (and H.264 for that matter):

https://youtu.be/71ebKrT2XlY


IMHO, the 0.7 release is a massive improvement over 0.6.  Solving the pink cast problem and at least most of the gain problems at lower resolutions is a HUGE deal.

One of my recommendations to them was to publish a LUT for both H.264 and Cinema DNG footage to give folks a good starting point.  They said they are working to find a color scientist that can help them out with this.   I expect they'll come up with something soon.

Once I have time to spend with the release 0.7 version, I will create a custom LUT with DaVinci Resolve using my 5600K lights that I can share if people are interested which might be a decent starting point.