Messages

331

Chronos User Discussion / Re: Chronos 2.1 color study

« on: July 07, 2021, 11:44:07 AM »

It's interesting to note that not only is there some serious color changes at the lower resolutions, but we're losing overall sensor sensitivity as well.  Is this a bug in the firmware or just an unfortunate characteristic of the sensor?  I'm not sure, but it's most likely the latter.

Noticed that as well.
 My non-Scientific Observations showed that Resolution does some Weird stuff to the Sensitivity, also that gain Settings are not equal to a linear increase in sensitivity.
 Furthermore Framerate also does some weird stuff to sensitivity. I feel like you tend to tickle more the Higher end of framerates, but for me its sometimes the Mid to lower end this camera offers. So i didnt look all too much into the High end, but for the Low end, there is some weird stuff happening, planing to do a new Topic on that at some point, namely exposure Slider at 60fps.
 .
 Now you didnt leave any info what Firmware version you did your test on, so i assume 0.6.0
 Now while Noise Output overally vastly improved with the New Firmware Version, Sensitivity took a noticeable hit at moderate Framerates (1k/full Res, didnt check lower res) and a somewhat bigger hit on lower resolutions.
 Tested 5.1 vs 5.1 Unstable vs 6.0 when 0.6.0 got released, and the 6.0 was just quite a bit darker. Dont remember clearly anymore but must have been somewhere between 1/3 and 2/3 of a stop darker overall or something on full Res./ 1kfps.
 5.1 Unstable is still the most sensitive (and ironically the most stable at stupid low framerates) from my tests, so i keep it on an µSD Card in my camera case to have it with the camera at all times just in case.
 So it has to be at least partially be Software.
 I dont remember to have any Resolution vs Sensitivity comparisons from what i remember, apart from noticing that Sensitivity on Small Resolutions on 6.0 is generally somewhat worse somehow (never did any actual tests to quantify that, just general feel).

332

Chronos User Discussion / Re: Poll - Please Vote: Which Lens Mounts do you want for the Chronos?

« on: July 07, 2021, 11:27:30 AM »

Was not meant as an offense to anyone, but seriously got me wondering after coming back like 2 Month later and still only 10 Votes, if there are just like 10 Active People on the Forum or if nobody cares about Adapters altogether.
 .
 Thanks for your reply, i didn't really ever think about it like that, but it makes a ton of sense to me now after your reply, that most existing users, especially those who already own/ use their Camera for a while will probably by now have figured out a way to use their lenses on the Camera in some Way or just bought lenses that fit their need for Nikon mount or something where Adapters are easy to get/ already come with the Camera.
 Like ofc they would, when there was no other option all the time.
 How else they would use the Camera...?
 .
 BTW, you should be able to change your vote or delete it completely, if you feel your vote at the time doesnt correctly represent your current situation very well anymore. (given i set the poll up correctly and this works as i think it does).

333

Chronos User Discussion / Re: HDMI output showing black only

« on: July 07, 2021, 11:16:19 AM »

I dont understand, what you are saying here.
 You are still getting a Black output on the HDMI means your Problem is solved or not?
 .
 Note that the Image output via HDMI is displayed quite a bit darker on most HDMI-Monitors i used than on the Cameras Built-In Monitor. In other words, the Internal Screen shows the Image very bright. Dont know if its the Gamma Setting of the Monitor or if its just generally Very Bright or a combination of both, but if you have a dark image on your HDMI Monitor, make sure that this is not the Problem and try to Shoot something brighter with the Camera.

334

Chronos User Discussion / Re: Chronos 2.1 noise study

« on: July 04, 2021, 11:51:49 AM »

It would also be nice to have a Phantom TMX 7510.

Damn, that thing is fast, but i would rather not want to know what that thing costs, i assume. Didnt check on Vision Research lately.
 For me it would probably be something more like a Phantom 4K and some PC that could handle editing and storing the Footage that thing produces (was actually some clips off a Phantom 4K that got me into Highspeed Cameras initially), if money wasnt a issue, but i get what you mean by that.
 .
 About the Green Chanel thing, maybe look into the PIPP Software, i assume it can do that. As far as Black Calibration goes, we are kinda Stuck with whatever the Guys at Krontech are able to get out of the Camera, but with PIPP or similar Software you can do quite a bit in terms of Debayering and what to do with which channels. I never extracted a Single Channel with it, but i think it should be possible. When using 0dB gain, you should have the Cleanest signal the Camera can provide in theory.
 .
 When i find time i might look into it a bit.
 

335

Chronos User Discussion / Re: Poll - Please Vote: Which Lens Mounts do you want for the Chronos?

« on: July 04, 2021, 08:26:46 AM »

Came back to this Poll after some time now and now i am wondering, how there is still just 10 Votes on here (one was from me, so 9 other people voted)...?
 Did this Poll just Drown in all the other Posts on the forum, do people not know how to vote here, or is everyone just using the CS mount on the Camera and doesnt need any other Adapter/ mount for some Reason (didnt think about adding an option for that, when i made the Poll)?

336

Chronos User Discussion / Re: Chronos 2.1 noise study

« on: July 04, 2021, 08:09:11 AM »

Yeah, I'm not talking about getting the best BW image from the camera as it is, that's not too difficult in post.  What I was wondering if there were some hardware level adjustments that can be done in the firmware to allow for better noise characteristics if you are only concerned with BW.  It's definitely not the same as using the BW sensor with no Bayer filter, but I was just speculating that maybe some of the amplifier gains could be tweaked (or turned off) if it could be run in single color mode or something like that.  This would require firmware changes, but it'd be neat option if it helped.   If you check the Chronos manual, they show the spectral response of both the color and monochrome sensors.  The monochrome is much better (almost double - thus the base ISO at 1000 instead of ISO 500), but if you look at the color graph, the green response is better than either the red or blue.  It might be possible to just read the green channel from the color sensor and tweak the gains to make it a pseudo BW sensor with slightly better noise.

 .
 i did read this a bunch of times, and still dont understand where you are going with this...?
 about the Monochrome sensor beeing more sensitive, yeah, thats kind of the point, why they even sell it that way.
 Dont want to be rude here, but I am not sure if you realize, even the UV-/IR-Cut Filter in front of the Sensor makes you loose like 10 to 20% of Light reaching the Sensor in the Visible Spectrum, a lot more in Invisible Spectrum (just a rough number as an estimate from very quick research, dont know the real numbers on whatever Filter they actually use in the Camera itself, so please dont quote me on that). Now that is basically just a Transparent bit of glass with not much to it for the naked eye. The Bayer Layer is a full on color filter in front of the Sensor, so of course its gonna make your sensitivity worse. about one Stop of light loss is about normal of what a Bayer Layer will eat up of your Light, which is pretty much the Difference between ISO 500 and 1000. The Graph in the Datasheet is, if you look carefully, the Characteristics of the Sensor itself. I am rather sure they just took that straight from the Sensors Datasheet and put it in there. So up to that point, its the Physical Sensor itself, we are talking about, nothing to do with the Camera at all yet.
 So that one Stop of loss in sensitivity is what you pay, if you want/ need Color on your Camera. Otherwise even Krontech themselfs highly recommend you to get the Monochrome Version, if you dont need color.
 .
 About the Green beeing more sensitive, also, thats kind of the Point of a Bayer Pattern Filter. If you take a look at the Filter pattern, you will notice that there are literally TWICE as many pixels assigned to capture Green Color than for blue and Red. So having twice the Area to capture said color, its kind of obvious, why it would be more sensitive.
 While there are a bunch of other types of patterns around, The Bayer Pattern is as far as i am aware by far the most widely used one. Green actually needs to be the most sensitive, because of the way human eyes perceive Light.
 .
 The other thing i could imagine you might mean, is that Krontech might try to drive the Lines / Rows of pixels at different gain/ voltage/ whatever (i dont understand the Hardware down to THAT level to know how you would actually do that if you wanted to) Settings because only every other line will have red/Blue Pixels in it, but i dont know if that is even Possible with the Sensor Hardware.

337

Chronos User Discussion / Re: Chronos 2.1 noise study

« on: July 04, 2021, 06:54:10 AM »

It would be nice if there was a way to program the default drop-down resolutions and base them on those 4 values, but I understand from a marketing standpoint why they want the standard HD and SD numbers.

Yes, i agree, user Customizable Resolution/ Framerate Presets would be a very neat upgrade to the overall Camera for one of the Next Firmware versions!

338

Chronos User Discussion / Re: Chronos 2.1 noise study

« on: July 04, 2021, 05:59:42 AM »

Personally, I don't think the Chronos is the right tool for the job at shooting anything below 300 fps.  Something like the Blackmagic URSA Mini can shoot 4K at 120 fps and 300 fps at 1080p.  Cheaper options like a GoPro Hero9 or a modern phone will give better results at 240 fps and below.  300 fps to 1000 fps is a bit of a no-man's land with current cameras.  The Chronos is really the only reasonably priced option that is a pretty awesome 1000-4000 fps camera but the base ISO of 500 is somewhat limiting.   To get good results with the Chronos in the 10k+ fps range is really challenging, but it's fun to play around with.

 While you couldnt be more right with that statement i have to politely inform you, that i own a camera that shoots up to 60fps in FullHD and 120 at 720p, and a Chronos.  Nothing else really. I also dont plan on upgrading or buying into an other Camera-System anytime soon. So, sure there are way better ways to do this, but while i have the 2.1, that can shoot these Framerates, i might as well use it for that, if you know what i mean. Then there is also the thing with low Light, i talked about in the Previous reply. There is just times, when i only got the Chronos on hand when i am somewhere, and there just isnt enough light for good Quality 1000fps, and 1000fps would be way too slow for what i am shooting anyways. So at least for me anywhere between 60 and 1000fps is a realistic usecase for the 2.1, even if it probably wont make any sense for anyone else.

I have a feeling the way the camera is windowing down the resolution and adjusting framerate/shutter is very complex at the hardware level. 

Yes. i very much assume it is.

I was wondering if it'd be possible to have an option to shoot the color Chronos in BW to try and reduce the noise or perhaps increase the base ISO.  I know the BW version of the Chronos uses a completely different sensor, but it'd be interesting if the color sensor could be tweaked in software in a way to get some of the benefit of the BW hardware.

not quite sure what you are trying to do there, but you could kinda run a Color Chronos in BW mode by setting every value on the custom Color Matrix to the Same Value (ideally use 1, tweak it a bit if you want to change contrast), see image attached.
 also the DNG data should still be per-Pixel Data, meaning undebayered, so using Software like PIPP (https://sites.google.com/site/astropipp/) you will still see what is basically a monochrome Image. I used PIPP to mess around with RAW files Quite a bit, helps you to understand what is going on really.
 anymore than that, and you would need to go and actually remove the Bayer filter Layer on the sensor itself, which i wouldnt recommend for multiple reasons on a camera like this, the main one beeing, that there isnt even a point in that, as Krontech literally sells Monochrome ones...
 For Reference and/ or anyone that has never heard of that:
 https://stargazerslounge.com/topic/166334-debayering-a-dslrs-bayer-matrix/page/1/
 .
 Noise Characteristics should still be unchanged from how i understand it however, but you gain a bit of Light from removing the Filter Layer (or just getting a Monochrome Version).
 Monochrome Cameras should however have less noise anyways, because of that bit of more light, and the camera generally doing a lot better in terms of noise if it has plenty light.
 If you dont mind a casual Magenta/ pink tint on some parts of the image because of some IR Light, you could also just remove the IR Filter, that will also give you quite a bit more light, and help with the noise. Will mess with your Flange Focal distances and your color however.
 but i guess the only way to know how the Monochrome actually does in terms of Noise, is to test one or ask someone who owns/ works one.
 Only Person i know that uses one is Lauri from Hydraulic Press Channel. Username on the Forum is hydraulicpresschannel. He should know, he uses a Monochrome 1.4 alongside Color Models. I dont know, if he still has/ uses his Color 1.4, but he at least had them in use right next to each other for quite a while in the Past.
 .
 

P.S.  Look into shooting 1472x720 instead of 1280x720.  I think you'll find there is no difference in speed and you'll have an extra 192 pixels to play with framing your shot in post.

 I might will at some point, but until now i just didnt bother remembering that quite specific Resolution. Standard 16:9 resolutions i can Quote from Memory, even if you where to wake me up in the middle of the Night and ask me, that one i would have to write down somewhere or something to remember. I guess i could try 1440x720, as that would be something, i will be able to remember no problem, but 1472px wide is quite the odd number to remember.
 .
 

Yeah, this was just an attempt at a scientific noise study, so the black frame is the best way to do that.  To scientifically measure dynamic range across the entire range of sensor options would be a huge task.

 Yes, thats why i never bothered to do a full on test worth publishing anywere, cause the amount of work that would take is just not fun anymore to do in my spare time.

339

Chronos User Discussion / Re: Chronos 2.1 noise study

« on: July 03, 2021, 11:06:04 PM »

[...]
 This type of testing should be reproducible fairly easily.  It might be interesting to see if different sensors behave differently.
 [...]

 From how i understand it, the Noise produced by any of the Chronos Sensors is like an Human Fingerprint of Sorts. Meaning that if you would know the Noise "Fingerprint" of every Sensor made, you should be able to figure out which Sensor shot what Footage (given you have Plenty of uncompressed Footage with enough Noise compared to "Image Signal" visible) with some Effort put into it. So, yes, each sensor should behave different. But only in terms of the Actual Noise Patterns itself, overall Noise Behavior should be roughly the same across Sensors of the Same Production Batch i assume.
 .
 Regards Everything else you said, i can confirm everything you wrote here about your testing. Done Plenty of tests Similar to this myself, but never quite in such a Scientific manner. Results where about the Same, but my focus was more on Full Resolution/ 1280x720 and lower Framerates (25, 30, 50, 60, 100, 120, 200, 240, 400, 500), as well as Full Framerate at 1080p and 720p Resolutions, and also the Higher end of Framerates. The Point of my testing was to see how to best shoot with as little Light as Possible (available Light Shooting in "Low Light" conditions, just in case if i ever needed to, cause i at some point probably will. also generally just good to know the true Limits of your Equipment in my opinion), and how much Framerate i would still be able to use in different Light Conditions. Naturally, i tested gain and digital Gain Combinations and also tried to see how much brighter i can still make the Footage in post.
 .
 From my tests the noise would behave about as one would expect, besides some aspects of it. I found that Shutter Speed and Framerate do also influence Noise quite a bit, which i didn't initially expect really. especially well below like 240fps (cant completely remember, just a guess) shutter speed changes noise noticeable, and low Framerates seem to have had a lot more Noise in it on my tests iirc.
 .
 I didn't really use a "black frame" to judge the Noise, but rather a "grey Frame", so a neutral Color with some exposure Level to it, or on later tests something that would cover the Full Dynamic Range of the Sensor and do a Pan across the Thing to see how different areas of the Sensor Respond to different Exposure Levels.
 While you still will get plenty of information out of a test like you did, comparing the Noise on a blocked Sensor, i personally didn't care all too much about that, as i can and usually will crush the Blacks anyways, especially if noise seems to show up there.
 So if you want to really get to know your sensor better, i recommend you to test the Full Dynamic range from Black to fully Clipping White.
 Found some characteristics/ problems of my Sensor, one wouldn't really notice otherwise.
 As an Example, My Sensor in particular has some weird vertical line of pixels about 2/5th of the way from the Right in the Lower half, that would have a weird red tint to it sometimes. But that would only show up in some Specific exposure Ranges/ on certain settings. Firmware 0.6.0 improved that by a lot, on 5.1 and before it was very visible and generally rather bad.  From my tests i found that if you expose carefully, and have Plenty of light overall (also using 0dB Gain helps, on latest Firmware higher gain is mostly save to use regards that, but is still visible sometimes), that usually never shows up.
 In terms of Noise, Light generally does help a lot with the Noise, but Harsh Lighting is still problematic. So somewhat evenly lit, bright Scenes will give the Best image Result.
 Now that i know it does that, i can stay away from Conditions that would probably make it show up. Also i know to look out for it, and will usually notice immediately if it shows up. Thats what i took out of my tests.

340

Chronos User Discussion / Re: Dealing with constantly-loosening EF-mount adapter

« on: July 03, 2021, 10:16:11 AM »

Adapter

 Is that an Image of your MFT Adapter?
 .
 #EDIT#: Also, whats up with the two missing screws?

341

Chronos User Discussion / Re: Review of Chronos 2.1

« on: July 02, 2021, 04:39:30 PM »

https://forum.krontech.ca/index.php?topic=671.new#new
 Just did a bunch more Testing regards the HDMI and Made a new topic for it. Can anyone having trouble with HDMI or also People with HDMI that works fine all the Time try to Recreate some of my observations to figure out if it is actually a reproducible Result across multiple Units, especially SergeyKashin, as you seem to have the most trouble getting the HDMI working reliably.

342

Chronos User Discussion / Re: HDMI output showing black only

« on: July 02, 2021, 04:34:24 PM »

I just had some Problems with the HDMI Out today and did some Detailed Testing on that Same Topic, see:
 https://forum.krontech.ca/index.php?topic=671.new#new
 Also Check out this Topic, where problems with the HDMI are discussed since quite a while:
 https://forum.krontech.ca/index.php?topic=596.0
 .

Is there a certain trick to getting the Ui output ?

 No, there isnt. HDMI will only output a Clean Signal. UI Overlay is not available on the Chronos 2.1 or 1.4.
 But you can try Web UI if you need UI on an Remote Screen.

343

Chronos User Discussion / BUG REPORT --- HDMI output Problems and Softlocking the Camera

« on: July 02, 2021, 04:29:24 PM »

As has been reported by multiple People here, there seems to still be some Serious issues with the HDMI Output (Chronos 2.1).
 For me It usually worked reasonable well, and recently i didnt have any issues at all. But today i had serious Problems getting the Camera to even output a HDMI signal once, when testing out some Exposure Settings.
 So today i decided it was finally time to have a detailed Look at this Problem and Do some Testing. 
 

[...]
 2. Camera doesn´t freeze everytime whenever i Plug HDMI in. I would say on average its somewhere between 1 out of 15 and 1 out of 20 times it would freeze as an rough estimate, but havent taken any records about it to give accurate numbers so far. Similar to what SergeyKashin is reporting, when it freezes, it most of the time does that also on the next 1 or 2 reboots also, untill it starts working normally again.
 [...]

 .
 Some References to previous / other discussions about this topic, before i get into detail of my tests:
 https://forum.krontech.ca/index.php?topic=670.new#new
 https://forum.krontech.ca/index.php?topic=596.0
 .
 .
 So i started with the following Test:
 (Exposure Settings for all of the Tests listed below where 1000fps at full Resolution at 357° and 0dB /0dB Gain also using Firmware 0.6.0 for all tests)
 .
 Test Nr.1
 Monitor used is the SmallHD 502 Bright via HDMI Input. This Monitor was used for all tests below.
 Test was done as Following: Monitor is Powered on, but HDMI is unplugged. Camera is Powered up and allowed to boot up, after the Camera first displays a Live Image from the Sensor, i would wait at least 3 Seconds, then Plug HDMI in. In case HDMI wouldnt output anything, i would wait 3 Seconds, and if nothing else happens, i would unplug it again, wait for another 3 Seconds, and Plug it back in. In case of a "Freeze" of the Camera/ Softlock Situation, i would have to Force power the Camera down. To give it a fair and Reproduce-able result, i have booted the Camera back up after any Freezes and Power it down normally again.
 Sample size was 20 reboots (reboots to "reset" the Camera after Freezes are not counted in this). Results where 20 times no HDMI Output at all (there is a signal, but the Only output is a static Solid black Frame), and after removing HDMI and Plugging it back in a Freeze on all 20 tries, after which the camera wouldnt respond to any inputs anymore, and the Displayed image on screen would go dark.
 .
 .
 Test Nr.2
 After this i did another test.
 This time, i Had the Monitor Powered off, but Plugged in already while the camera was still powered off. I would then boot the Camera up, allow the Camera to fully boot, and also wait for at least 3 Seconds after the Camera outputs the first live Image Output on the Internal Screen, bevore powering the External Monitor on. After each test, i would first power down the Camera, wait 3 Seconds to Power down the Monitor, wait another 3 Seconds for the Next Boot /Reboot. If i would run into a Freeze, i would do the same as on Test Nr.1, and reboot the Camera to make sure i was powered down correctly bevore the next try.
 Sample size on this Test was 104 Reboots (also not counting The Reset-Boot-Cycles for the Freezes).
 Result was 100 "normal" boot-Cycles, where HDMI would work as intended, and 4 Freezes.
 Those Freezes Happened on Boot Nr. 3; 44; 45 and 73 out of 104 Total Reboots.
 .
 .
 Test Nr.3
 As i feel like i didnt quite wait the Full 3 Seconds (about the Time the Camera still shows "No Batt" on screen and needs to switch to the Actual Voltage and Percentage after first Image Output is Displayed), especially on Boot Nr. 3 and 73 of Test Nr.2, i did a Control-Test, where i used basically the Same Testing rules as for Test Nr.2, but would Power up my external Monitor shortly before, while, or very shortly after the Camera would display the First Live Image Output from the Sensor.
 Sample Size was 5 Reboots on this, all 5 of them just worked normally, and displayed Proper HDMI Output Image.
 .
 .
 Conclusion/ Summary:
 While i still dont really understand whatever is going on here, i would claim to have found a reasonable reliable way to get a Freeze and a somewhat reliable Way to get an HDMI output working on >>90% of Boots.
 There is still a lot more going on, and a lot of more testing to be done, because it can be really inconsistent sometimes, but for the described order of operation it seems very reproduceable in terms of Results, at least for my Unit.
 .
 .
 Further Notes:
 .
 There is some other weird stuff going on, i noticed.
 For this series of tests i just Rebooted the Camera a total of 158 Times (a bunch more before i started systematically testing, but didnt take any notes about this).
 During all those Reboots, i noticed that the Camera would just randomly allready be recording right after Boot, while the Option "Auto Record" is not enabled on my camera, and also never was during all the Testing, i checked multiple times after i noticed. This happened 18 times out of the 158 Reboots. While this isnt really an issue (at least for me...), i think this is also not supposed to happen, and i couldnt figure out, why it would do that. Never Rebooted that many times in a Row, so i never really noticed or questioned that, and just assumed i would have accidentally hit the Record Button whenever it happened, but on those tests i was sure i had not, also happened quite often (>10% of Boots).
 .
 On 2 of the Boots, the camera took like a full minute to then decide it couldnt boot, powering down completely, and then booting normally, without me needing to do anything more than wait. One was right after a Freeze, so i would consider that "out of normal Conditions", but the other one happened just randomly between two of the Working Tries on Test Nr.2, so that was somewhat surprising.
 .
 On one of the Reboots, the camera just showed a really glitched out Image on screen, i didnt even bother trying the HDMI, and just restarted, but took an Image of if, see attachment. Never had this happen since i have the camera, but seen someone else post something just like this on the Forum somewhere. Worked just fine the Next after a Restart of the Camera.

344

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

« on: June 28, 2021, 07:32:58 AM »

Me and Forum User peeccy meet up and did some Product-Photography -Type Test-Shots with my Chronos, so he could get hands-On with the camera and see how it will perform for this kind of work he might wants to use it for in the future. Result isnt perfect, but we had fun shooting. Opening Shot at 2141fps, everything else at 1000fps. Lights overall where about 1000W LED all together, two of my big Godox Lights and some of his Aputure and some other Lights. Also just some quick and Lazy editing of the whole thing with no sound or anything.

345

Chronos User Discussion / Re: Hyperfocal distance

« on: June 23, 2021, 08:39:41 AM »

So the Circle of Confusion is mostly just two things:
 1.  On an ideal, theoretical lens, which creates an perfectly sharp Image with an Ideal Sharp Rendering of the Focal Plane (note that for this assumption only this super thin (an Actual geometrical Plane) Plane would be actually in Focus, no matter the Lens Aperture, everything else is assumed as Unsharp. Basically saying Depth of Field would be 0,00mm, just to understand the Theory behind it a bit better), the Circle of Confusion describes the size of the Circle, at which a theoretical, infinitely Small Light Source would Render when out of Focus, no matter how small that would be. You for sure have seen or heard about the Term "Bokeh Balls", which a lot of Photographers like to throw around when talking about Superfast Lenses and such. Basically those are the Confusion Circles of whatever (not quite theoretically ideal and super small) Point Light Sources, rendering actual Circles of Light on the Sensor.
 2.
 On an Real World Lens, Circle of Confusion also comes into play when a Lens Designer sets out to Create a New Lens. This is a Parameter they have to keep in mind, and it basically represents (talking about the In-Focus-Plane, where on the ideal Lens, everything rendered on the Sensor would be an absolutely Flawless Reproduction of Reality, and a geometrical Point would be rendered as a Point) all the Flaws in the Lens Combined. Look up Aberrations if you want to know more about them (https://en.wikipedia.org/wiki/Optical_aberration), but for now lets just say, real world Lenses make all kinds of "Mistakes" when Rendering an Image. So the Circle of confusion in this Relation means, the maximum size of deviation from an ideal Rendering of a Point when in focus. When a new Lens is Calculated, keeping this Circle of Confusion in terms of Optical Aberrations as Small as possible is very important to give a Final Image, that has as much Detail as Possible.
Keeping the Maximum Circle Of confusion as Small as Possible has Limits however, because at some Point improving it beyond a certain point will lead to the need of a increasingly Higher Precision When manufacturing the Lens, a More Complicated Lens Design, a vast increase in Size and/ or Weight of the Lens and of course a lot more expensive Production Process (or multiple of those things Combined). Thats why Cheap Lenses are often not as "sharp" as others, and why the Last bit of possible Resolution and Lens Quality will allways make Lenses WAY more Expensive than Similar other lenses (also Size/ Weight).
 .
 So, as an Conclusion, Circle of Confusion is what limits your Resolution pretty much. For Film, that would be whatever size you are Expected to Print it at, and some kind of Viewing angle Rule to determine the Circle of Confusion (there is some kind of rule of how small of an Angular Resolution the Human Eye can Resolve, and from that, the expected Viewing distance, and Print Size you can Calculate the maximum allowed Circle of confusion, bevore anyone can tell its "unsharp", but i dont know that anymore and cant be bothered to look that up rn, let me know, if you want to know more). on Higher end Film lenses, they sometimes tried to even limit maximum Circle of Confusion to the Grain size, as Film cant just resolve anything more than that physically.
 For Digital Sensors, the Circle of Confusion is also what limits Resolution. If you look at Machine-Vision Lenses, the Better ones Have Megapixel-Ratings. Thats nothing else, than just openly saying what Maximum Circle Of Confusion they are designed to have (obviously also tested to do so), combined with the Size of Sensor they are built for. So basically a Guarantee that they can Resolve at least that many Pixels, across the Full Sensor and Range of Focus.
 Now in Terms of Depth of Field, its somewhat similar. To be able to calculate your Hyperfocal Distance/ Depth of Field, you need to know at which point something is considered "sharp" or "unsharp", as there is technically just one Plane of space to ever be actually in Focus, according to theory. In Reality, as discussed earlier, there is a certain threshold to cross for us to actually perceive it as Unsharp. On an digital Camera, this would usually be the Size of the Physical Pixels on the Sensor. If the Circle of Confusion is smaller or as big as the Pixel itself, you couldnt tell a difference from if it was perfectly sharp, as it will become a Pixel anyways. Cant resolve anymore detail, even if it Tried somehow. Only if the Circle of Confusion gets noticeable bigger than your Sensor Pixel, you will be able to tell, that its unsharp from the Recorded Image on the Camera because it will now render your point to more than just that Single Pixel and start to influence the surrounding Pixels also (or full on cover multiple Pixels).
 .
 For the Chronos, you would just look up the Pixel size ( /-Pitch, see below) in the Datasheet, and take that as your Circle of Confusion Value for your app (or Formula if you do the Calculation on your own).
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 According to Datasheet:
 1.4:
 Pixel Pitch: 6,6 µm
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 2.1:
 Pixel Pitch: 10 µm
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 Note, that they give Pixel Pitch here, not Pixel size, as on an Digital Image Sensor the Size of the Pixel is usually smaller than the Pitch, because all the Circuitry has to also fit on there, and Light sensitive area is mostly not 100% of the Sensor Area. So Pixel Pitch is the Value to look out for, because it is the Spacing of the Pixels, and given a circle of Confusion of 10µm on the 2.1 Sensor, it would still give a perfectly Sharp image, even if that is more than the Actual Pixel area, because it ever just covers a single Pixel in size.
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 I hope this wasnt too confusing, and did help you with your Question.