Messages

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Chronos User Discussion / Re: Chronos 1.4 Footage Thread

« on: May 04, 2022, 10:34:59 AM »

Thanks mklinger! Yeah, I don’t know if this is an issue with the 1.4, but I believe if you try to change your white balance in post too far, it can get real strange as if it’s not really a RAW file. You really need to get the 1.4 balance as spot on as you can even when shooting RAW. Is this something the 2.1 exhibits as well when pushing the white balance in post?

Yes, the 2.1 can't be pushed too much in post either.  What I think is happening is that because the dynamic range of the sensor isn't very good (compared to modern DLSRs or standard video cameras), the process of getting the colors correct to begin with using a basic LUT essentially uses up most of that available dynamic range. 

It is extremely important to try and get the exposure as correct as possible when filming and use as low a gain as possible (0dB ideally) to maximum what dynamic range is available so there is some flexibility. 

There is a reason the Phantom cameras cost 6 figures... their sensors are much better.  I'm not complaining though, both Chronos cameras offer extreme value for high speed shooting that isn't possible with any other camera, but you really need to shoot in ideal conditions to maximize quality.

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Chronos User Discussion / Re: Chronos 1.4 Footage Thread

« on: May 04, 2022, 09:34:23 AM »

Here is a very short Chronos 1.4 RAW DNG Test I did under cloudy conditions graded in Davinci. It was then upscaled to 1440P through Topaz VEAI. I hope Krontech can work with a color scientist and get some LUTS for the 1.4 and 2.1. Also, I was hoping they can add a way for us to fine-tune the white balance manually by having a Kelvin option.

https://www.youtube.com/watch?v=6Aq-S_RvBTE

That looks pretty good.  I agree, although, FWIW, the concept of in-camera while balance doesn't really mean anything when shooting RAW, only the mp4 record options.  The colors from that sensor need much, much more than a white balance adjustment to get them looking good.

You should have decent luck using a daylight LUT and then adjusting the color temperature in Davinci to account for cloudy conditions, but it might need some other tweaks  as well. 

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Chronos User Discussion / Re: Chronos 1.4 Footage Thread

« on: May 04, 2022, 07:57:56 AM »

Hello everyone.

The LUT mklinger provided for the Chronos 1.4 was made for clear sky light conditions, so it's normal that it doesnt work ok on different situations.

I found that using the LUT in theses situations got me some bloated colors (specially red/magenta) and really heavy noise on those areas. Noise I could not get rid off. (I'll try to find footage to show this problem).

So I had to tweak colors myself, after a while I got a pretty decent balance between colors and noise, but I figured a custom LUT for cloud skies would be a better fit.

Anyway, right now is not the best time to make another calibration start point, since ain't cloudy around here, but If conditions allow, I'll try for a cloud sky calibration data, if @mklinger could work on it it would be nice...

Nick, your footage looks amazing, vivid colors!!!

Regards

Henrique

As Henrique mentioned, a single LUT is only good for the lighting conditions it was made with.  Same for mp4 vs Cinema DNG.  Because I don't own a Chronos 1.4, I can't easily make new LUTs for that system.  The one I made for the 2.1 was made using very controlled LED lighting simulating what I normally shoot with.  It should also work well with daylight conditions.  I believe the images the 1.4 was taken with was under daylight conditions, but it might not have been ideally controlled.

If you have a good color chart, it's not that difficult to make your own with DaVinci Resolve with a little research.  Resolve makes the process very easy to create them once you have things dialed in.

I've been hoping that the Kron folks would publish and include official starter LUTs for these cameras and it's certainly required for shooting in RAW in my opinion.  It can also help a lot with mp4, but I typically only shoot RAW so I haven't worried about that too much.

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Chronos User Discussion / Re: Chronos 1.4 Footage Thread

« on: May 04, 2022, 05:10:04 AM »

A simple color correction test thanks to mklinger’s custom LUT.

https://www.instagram.com/tv/CdGxG4sjFM6/?igshid=YmMyMTA2M2Y=

Your footage looks good!  I'm glad you were able to use the LUT I created.  The 1.4 LUT was created from another user's data as I only own a Chronos 2.1.  That one is certainly not as refined as the one I created for the 2.1, but it looks like it's working great for you.  Thanks for sharing!

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Chronos User Discussion / Re: Long-term sustained capture (1TB of data) to SB or and network?

« on: April 20, 2022, 06:55:13 AM »

We have a pair of 2.1 camera and have used them very successfully for one project -- but we had short clips downloaded vis SD cards since at that location we did not have network.

We are thinking of using them on a new project that would require a small window (maybe 128x128 image) captured as fast as we can.. but need to capture for a  moderately long term  (8hrs a day for 50 days). 8hrs at 7500fps of 128x128 is about 1TB but I can download over a network at outside the capture window.  I see 2 ways..  capturing to a large SD card in the camera or a USB SSD in the camera (a 1TB class 10 card should hold 8.6 hours) and then remotely access afterward via SMBor streaming over the network interface and capturing on the computer.  The streaming view over the network says it supports 1920x1080@60fps but I presume that is H264 and I need uncompressed.  Looking through manual I did not see any way to stream uncompressed.. anyone find a a way?  An alternative would be to  save to NSF  but have no idea what sustained rate I could do.   


Can anyone comment on experience with the tradeoffs between long-time SD capture and long-time network capture?  Am what I am describing even possible or I am limited to 32GB of capture then stop recording to dWe have a pair of 2.1 camera and have used them very successfully for one project -- but we had short clips downloaded vis SD cards since at that location we did not have network.

We are thinking of using them on a new project that would require a small window (maybe 128x128 image) captured as fast as we can.. but need to capture for a  moderately long term  (8hrs a day 50 days) and download over a network at outside the capture window.  I see 2 ways..  capturing to a large SD card in the camera (a 1TB class 10 card should hold 8.6 hours) and then remotely access afterward via SMBor streaming over the network interface and capturing on the computer.  The streaming view over the network says it supports 1920x1080@60fps so at 128x128 the data rate seems like we might get 7500fps at the same effective pixel/data rate.


Can anyone comment on experience with the tradeoffs between long-time SD capture and long-time  network capture?  Am what I am describing even possible or I am limited to 32GB of capture then stop recording to transfer/download?

Yeah, the Chronos can't do what you're suggesting here.  The first problem is that the current minimum horizontal resolution is 640, so you'd be dealing with 640x128 images.  Second, the camera can only record high speed to the internal RAM buffer, so you are limited to 32 GB like you say. 

As you have probably discovered, offloading the data from the RAM buffer to any external device (SD card, SSD, or Network) is pretty slow, so that will be a significant bottleneck.  The fastest option eSATA w/SSD would be less than 100 fps offloading, so 75x slower than your recording rate.

To achieve continual shooting the way you are thinking would require many (100+) cameras all coordinated and programmed to overlap.  It would be very complex to set up if it's even possible.

I would look to other cameras for this project, but I don't know of any high speed cameras that can currently do what you want but there may be some machine monitoring commercial cameras that can do that, but I'm not sure.  Definitely nothing mainstream can record continually at 7500 fps for 8 hours a day.

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Chronos User Discussion / Re: Post Chronos 2.1 clips here!

« on: March 04, 2022, 11:48:32 AM »

This is the final part in a big optimization series I made.  This one is the "extras" and shows all the high speed footage of 22 bridges breaking at 5040 fps.

https://youtu.be/1rsseEjnRVA

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Chronos User Discussion / Re: SSD Will the speed of the drive make saving faster?

« on: February 10, 2022, 12:10:46 PM »

Ah! Thank you.
I don't want to complain too much :p But I did spend around 6 different search terms trying to find the answer for it
I also cannot find anything on "change iso" which I would like to know how to.

The Chronos uses "gain" instead of ISO nomenclature.  The base ISO of a color Chronos 2.1 is roughly 500 which corresponds to 0dB gain.  If you select 6dB of analog gain, it's like changing the ISO to 1000.  12dB = 2000, etc.  The base ISO of the monochrome Chronos 2.1 is around 1000, so almost twice the sensitivity.

I believe, but I'm not 100% sure, that digital gain is just adjusting the exposure curves and doesn't do anything to the sensor readout and it'd be the same as doing it yourself in post.

If at all possible, try to stay at 0dB gain for best quality, which usually means tons of light.  6dB and 12dB have become much more usable with the latest firmware, but there are quality tradeoffs.

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Chronos User Discussion / Re: Post Chronos 2.1 clips here!

« on: January 24, 2022, 11:55:51 AM »

Here is some pretty cool footage of a 4494 efficiency balsa bridge exploding at 5040 fps.

https://youtu.be/gq_d13j-FzI

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Chronos User Discussion / Re: Can't find the 2.1 LUT thread, please help!

« on: January 19, 2022, 04:28:16 AM »

Hello, I remember that there was a LUT table for the chronos 2.1 posted here somewhere. SInce I don't have a color chart, I would like to try with that.

Can someone point me to the thread, I can't find it.

Thanks a lot! Martin

Hi, that was my post over in the "Software Dev" part of the forum when they announced the new firmware.  Here is the link:

https://forum.krontech.ca/index.php?topic=687.msg4734#msg4734

I hope the LUT works well for you!

Marc

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Chronos User Discussion / Re: Best (fastest) studio config in client + agency setup

« on: January 16, 2022, 03:39:34 PM »

Yes, I would only use CinemaDNG

From specs alone Gigabyte Ethernet is 100Mb/s
So possibly it could get close to the 60Mb/s quoted elsewhere for SSD save speed.
For replay it looks like my best option is feeding the HDMI out into a recorder that cross converts to SDI (the Blackmagic Videoassist 12g does, not sure about Atomos) and hit record every time I replay a clip. From the recorder on I can cable all monitoring with SDI as I would with my Red. That makes swapping cameras faster as well as I often only have one or two High speed shots and the rest would be shot at 25-120fps on Red.

I would say 60 MB/s to the SSD is more of a best case.  If you shoot faster/smaller files, it won't be as fast.  For example, the latest work I'm doing is at 1152x380 at ~5000 fps.  That save settles out at around 40 fps saving with 859 KB CinemaDNG files, so about 34 MB/sec.

The camera has overhead with creating the files from memory, it's not just transferring the data. 

I have done remote transfer via gigabit Ethernet, and it's slower than saving to SSD which is not surprising as there is even more overhead to create the proper network protocols.  Even in a studio environment, your fastest solution will most likely involve saving the data to an SSD and then physically moving that SSD to the computer and load it via USB3.  That is what I typically do and it works well.  I don't think there is any faster way to get the data to a computer for post processing.

For just replay/proofing, something like an external display and recorder via the HDMI output would probably work well, but I haven't done that. 

If the purpose of immediate review is to determine if you need to reshoot, just using the camera's monitor is quick and easy and by the time everything else is going, you can save the segment to the SSD and move it to the computer for proper viewing.

FWIW, I don't think there is a single high speed camera that is "fast" in the same way normal video cameras are.  Even Phantoms record to memory and have to save to external devices which isn't fast.

Also, remember for best results you'll need to account for about a 20 minute warmup time and black calibration every time you change settings.  Again, all high speed cameras are currently like this from my understanding.

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Chronos User Discussion / Re: Post Chronos 2.1 clips here!

« on: December 16, 2021, 06:09:00 PM »

Here is a video where I examine the failure mode of a balsa bridge (for a Science Olympiad competition).

https://youtu.be/JDJaApyUits

The high speed footage starts around 1:50, and just before that you can see the real-time version as well.

This was filmed at 1152x380 resolution at 5040 fps, 180 deg shutter, and 0 dB gain using two Godox VL300 lights with Aputure Fresnel 2X attachments.

I was also using my new Rokinon Cinema 35mm T1.5 lens at f2.8.  This is an EF version of that lens attached using the fantastic new MFT mount!!  That thing makes these larger lenses much more secure.  If you haven't picked up one of those mounts, I highly recommend it!

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Software Dev / Re: Chronos V0.7.0 Full Release

« on: November 04, 2021, 08:04:04 AM »

No problem!  I look forward to seeing your results and how well it works for you (and others).

Thanks!

Marc

Hello everyone, here are the results for the 1.4 LUT mklinger provided

Video 1 - Edited with the 2.1 LUT
https://youtu.be/hk574eqvOSc

Video 1 - Edited with the 1.4 LUT
https://youtu.be/qAiHIHU5jls

Video 2 - Edited with the 2.1 LUT
https://youtu.be/ushuhDhV7P0

Video 2 - Edited with the 1.4 LUT
https://youtu.be/49S8JEYKECo

Video 3 - Edited with the 2.1 LUT
https://youtu.be/wLA-mYE9scc

Video 3 - Edited with the 1.4 LUT
https://youtu.be/sX1ivF2zGCA

Other video edited with no LUT corrections, I did color correction manually, just for comparison
https://youtu.be/_Jvbliyt4As

My thoughts, first a huge thanks to Marc for the LUT and patience explaining everything.

I think it is a huge impromevent from where I was on 0.7.0 FW without LUT adjustments, or using the 2.1 LUT (strong red tint), I'm still figuring out how to properly correct everything, it's hard, sometimes I still tend to be a little heavy on some color tints (a little bit too green for now), and it is very monitor dependent (I'll have my 2 monitors color corrected as soon as possible), but I'll get there.

Really happy with my progress so far, two years and I learn tons everytime I go out to shoot something, thanks everyone for the help here!!! The LUT will definitely help, I'll stay on this FW since it's way faster on save times...

PS. sorry for the videos, mainly out of focus and just straight 1000fps played back at 30fps very slow and boring stuff lol

Your footage is looking pretty good.  Definitely don't bother with trying to use the 2.1 LUT with your 1.4.  That will just cause you more headaches than it's worth.

Keep an eye on exposure.  Your video 1 and 2 look pretty good, but #3 looks a bit underexposed (you should be able to boost this example in post without too much problem).  Once you get the colors dialed in to exactly what you want, don't be afraid to boost the saturation a tiny bit to make the video "pop" more.

Overall, it's looking good.  Good luck with your future work and I'm glad I could help!

Marc

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Software Dev / Re: Chronos V0.7.0 Full Release

« on: November 02, 2021, 02:58:07 PM »

Thank you Marc!

I just downloaded the LUT, will try on some old data I kept on my SSD for this... I'll let you know how it goes, perhaps I have my own old edits for the same footage to compare!!

Again, thanks so much for the help!!!

No problem!  I look forward to seeing your results and how well it works for you (and others).

Thanks!

Marc

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Software Dev / Re: Chronos V0.7.0 Full Release

« on: November 02, 2021, 02:52:27 PM »

User muringuets was able to send me some sample Cinema DNG output from his Chronos 1.4 shooting a color target and I was able to take a stab at creating a custom LUT using DaVinci Resolve.

It's not perfect, but it should be a very good starting point, especially for daylight work.

You can download the LUT here:

https://klingerphotography.com/Chronos14/Chronos14_v7_daylight.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

Below you can see the before and after version of the color chart when the LUT is applied.

Let me know what you think and if this is useful for folks with a Chronos 1.4 trying to shoot in Cinema DNG with V7 of the software.

Thanks!

Marc

15

Software Dev / Re: Will there ever be a 100,000 FPS version again?

« on: October 23, 2021, 05:39:13 AM »

I have requested a full datasheet from Luxima.  I'll be curious to read some of the actual details and limitation of the sensor.   I would bet the 700k FPS figure is something crazy like 32x8 pixels and the rest of the hardware would need to be specially configured, but the datasheet should spell that out.  Because the Chronos 1.4 can actually do ~110k FPS, my guess is that the image overhead for those kinds of speeds would also be possible on the 2.1 as the rest of the hardware is essentially (maybe exactly) identical.

A quick check of the H.264 codec wiki makes it seem that very small vertical resolutions should be possible, but it's extremely likely that the library they are using on the Chronos has a limit.  H.264 is a very complex codec and is really optimized for large resolutions and block sizes.  Just having raw image support at these experimental resolutions would be totally acceptable to me, but they might not want to do that.  Personally, I never use the H.264 output and always using DNG for maximum quality.

I have quite a bit of software development background and am very comfortable reading their code, but it's complex not because the code is complex, it's complex because the algorithms implemented to handle the hardware are complex.

Once I see the datasheet, I may make a copy of the firmware and start playing around with it for fun.

Any Progress / Updates on the 2.1 Datasheet /-mod?

Luxima did send me the full data sheet on the sensor.  There were some really interesting things in there that I learned, but nothing jumped out that would allow for < 96 pixel height and faster speeds.  I think the sensor can do it, but it's probably not practical.  Really, with a base ISO of around 500, it would be extremely challenging to get enough light for anything more than it currently does.  Even with direct sunlight, that is only enough for about 10000-20000 fps.  Anything faster than that, you are pushing the noise levels pretty high and using artificial lights to get brighter need to be so close, you run into heat issues.  I contend that this camera is really the best option for 1000-5000 fps, and pretty good from 5000-10000 fps.  If you really need to go faster with high quality, you'll have to step up to a Phantom. 

A couple interesting things I did learn from the datasheet.  The sensor supports up to 8 regions of interest, meaning separate windows that can capture at the same time and they can all be different sizes.  This shows its roots in assembly line machine vision tasks and that would be something that could be useful in those applications.

The biggest news for me was that I saw that the LUX2100 supports pixel binning up to 2x2.  That is a way to combine the light gathering of multiple pixels to gain sensitivity with the tradeoff being a loss of native resolution.  I was really interested in this as it could potentially be a way to get a much more sensitive sensor.  Various cameras like some Phantoms can do that quite effectively.

When I reached out to the Krontech folks asking about it, they confirmed that the LUX2100 is ALREADY using 2x2 pixel binning and that is in fact, just a LUX8M (4K 250 fps) sensor with pixel binning turned on and a different Bayer filter attached to the front.  I speculated that the monochrome version of the Chronos 2.1 could potentially shoot 4K at 250 (as there is no Bayer filter at all installed), and they agreed, but they aren't currently working on that as the market for that would be small.  I thought it was very interesting though.  This makes a lot of sense if you read Luxima's product page carefully:

https://www.luxima.com/imageSensorProducts.html

The LUX8M and LUX2100 look identical and really are for the most part.  Very clever of them!


I am extremely happy with the performance I'm getting in the ~3000-3500 fps range where my primary use case lives and with the new firmware, things are looking good across pretty much the entire range of camera.