KronTalk
Chronos => Chronos User Discussion => Topic started by: Solscud007 on November 01, 2021, 09:19:57 PM
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So I’m still waiting on my Chronos. Has anyone captured video under low light? I want to capture a faint light but I know the Chronos needs a lot of light to light up the subject. Won’t that wash out the faint light I am trying to capture?
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Define "Low Light"...
While the Chronos Cameras do need a ton of Light compared to most usual Modern VDSLRs and such to produce high Image Quality, they can still offer somewhat decent Light Sensitivity if needed. Image usually does look "not as nice" to "pretty bad", if you do that, but if just capturing something to see what is going on at all is your goal, it is usually able to.
I dont know about the 1.4 in particular, as i am an 2.1 Owner and user, but for the 2.1, the Higher Framerates dont work with High Gain Settings. Meaning, for The Higher Framerate Stuff this camera is capable of, you will still need a Lot of light no matter what, but for the "lower End" of Framerates up to like ~3000 or ~5000ish FPS you can push Analog and digital Gain quite a bit.
Also depends on your Lens.
If you have some Ultra Fast Lens, which is very Possible on the 1.4, you can capture a lot more Light than with some Standard Lens.
Now most people would probably already use an 1.4 with something like that f/1.2 Zoom Lens, so you wouldnt gain a ton from going to a f/0.9 Prime Lens or something like that, but a 0,58x Speedbooster with an f/1.2 Lens on it would give f/0.7 which is quite a bit and worth considering (Metabones 0,58x Speedbooster would work very well for the 1.4!).
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I did quite a bit of Low Light Testing with my 2.1, mostly to figure out how well it would be suited for available Light Shooting in Everyday Lighting Situations without being able to add or Modify Lighting.
. Can you provide any kind of Reference Exposure Settings /camera Model you are able to capture Said Faint Light Event with to give an Estimate of how bright it actually is? Like ISO 6000 1/60s f/2.8 or something, that would help a lot actually answering your Actual Question itself.
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Hmm I will have to look into that speed booster. I plan on using a 50mm f/1.3 computar lens that I have.
I don’t have specs. But I want to try and capture the spark from a Winto-green life saver. I guess I should have just googled it. Smarter Everyday did it with a phantom. And I was surprised how bright it is it and the camera was able to capture the lighting.
https://youtu.be/tW8q_JfmcbU
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Seen that Video, and was pretty impressed myself, that they were able to capture that.
Just as a very wild guess, id say at 1000 fps you will have a fair chance of capturing that with an fast lens, and YES, i would highly recommend that 0,58x Speedbooster for that. Not sure if f/1.3 will cut it for that, you will be happy for any bit of light you can get for stuff like that!
Up to 3500fps you probably would be able to do capture it on an 2.1, but dont quote me on that.
Anything above might be possible, but pretty sure wont look pretty, if you are able to make it work (that being Said, i dont know how the 1.4 behaves in low light. HPC was able to capture quite impressive "low Light" stuff with their Monchrome 1.4 at High framerates).
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I mean, given that the Thing emits light when hit hard, you can still always find a way to just somehow hit it harder and make it emit more Light ;)
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Thanks. I’ll give it a whirl. Can you point me in the direction of the proper speed booster? I tried looking at Metabones but didn’t see anything specific for C-Mount. Or would I need an adapter? I bought a Canon to C-Mount adapter. Would I then add the speed booster to that adapter and a faster lens on the speed booster?
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well, getting the Correct Speedbooster is one thing, Mounting it to the Chronos is an entirely different Beast to tackle!
The "correct" or better said clean and Easy way would be an interchangeable MFT Mount Plate for the Chronos, There is Quite a bit of Info on this Forum already about adapting MFT or Speedboosters to the Chronos, if you want check it out. However, i currently am in the Process of writing an very detailed DIY Guide specifically on how to attach Metabones Speedboosters to the Chronos Cameras and also on how to adapt anything else MFT-Mount onto an Chronos. Still Heavily in Progress, expected to hit the Forum Soon, maybe might as well wait for that, should be an order of magnitude easier to do than anything else we have available so far in terms of options, but cant release that yet, still incomplete.
Will post a Link to that Thread, when its done.
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Cool. I look forward to checking that out. But it will be for the 2.1 right? The 1.2 is different.
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Mechanically the 1.4 and 2.1 are completely identical (on the outside at least).
Even Screen and some of the Circuit Boards inside are the Same and you could interchange them between each another.
RAM, Batteries, Fan and IO/ Buttons are all the Same, Firmware is the Same.
Mainboards are similar but need to be a bit different, Sensor and Some of the Cooling is completely different obviously.
Meaning apart from the Sensor and the Mainboard its basically the Same Camera.
Meaning also, you can use any Adapter you can fit onto an 2.1 on an 1.4 and the other way around also.
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I also recreated the Life Saver video with my high speed camera - not a Chronos but a PCO dimax HD.
It's important to use the Wint-O-Green version since the included oil shifts the light into the visible wavelength. I totally missed this at first and hammered lots of normal ones.
I recorded with 5000 fps in RAW and then tried to squeeze everything out of the images when converting them to a video.
I come nowhere close to the quality of the Phantom shots, but I see the sparking quite well which made me happy.
YouTube is doing terrible compression thing to noisy videos, so if you want the original files, PM me.
https://www.youtube.com/watch?v=vzPAz24czHM (https://www.youtube.com/watch?v=vzPAz24czHM)
https://www.youtube.com/watch?v=iWxgRPquz3w (https://www.youtube.com/watch?v=iWxgRPquz3w)
(http://LifeSaver5_00105.jpg)
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The first Linked Clip is indeed Pretty bad, but the Second one is pretty respectable actually.
Can you share any info on What Lens you used or Settings like Shutter Speed / Sensitivity settings for a Exposure Reference?
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After that discussion yesterday i just went ahead and ordered a Pack of those (never had any of them myself so far) to just might as well try myself and give a Reference for Exposure Settings to use for that and what kind of framerate you would be able to push on a Chronos 2.1.
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Just went and checked, and i luckily ordered those "Wint-O-Green" ones you said, they are actually the only ones that seem to be available here anyways.
Should arrive until the Weekend, will post something, if i find time to try that myself and am able to capture anything.
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Thanks a lot for the info about which ones to use anyways, Rainer, you probably saved someone a bunch of time trying with the wrong ones (i got lucky to just order the Right ones)!
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my lens/settings were the following:
PCO.dimax HD with Zeiss 1.4/50mm lens (Nikon DSLR Mount)
5000 fps
720x684 pixel
0.179100 ms exposure time
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Ok, well that doesnt seem too crazy.
if i did my math right, that would be like 322° Shutter angle at 5000fps with an f/1.4 Aperture.
Do you still remember the Gain Setting or whatever unit that camera uses to adjust sensitivity?
Just looked through the datasheet, and i dont really get their Iso ratings in there which they are giving, info seems somewhat obscure.
But from a Quick look; Sensitivity, at least on paper, should be somewhat comparable. .
From that it seems very realistic that the Chronos can capture that at maybe up to 3 or 5 kfps with a fast lens.
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There doesn't seem to be a gain setting in this camera. At least I did not find one in the manual or software. I always records in RAW and with a histogram-like window I can convert these RAW images into JPG or other formats. For the low light shots I tried to squeeze the brigt light out of these RAW images as much as possible.
I am very interested if anybody else is recreating the Life Saver shots!
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They arrived today. Must say, i am Impressed. not only by how bright that Flash actually is, but also that this made an even bigger mess than i expected. Also How damn Light Sensitive those Phantoms must be, to capture that this well at those framerates. But also shows, why they probably cost so insanely much.
Like i guessed 1000fps is no problem, and up to 2100 is still looking ok, up to 3500 fps is possible, but looks fairly bad, above that you will really have Trouble seeing that Flash well through all the Noise, have not even tried anything above 6000fps. On my 2.1 that is, cant speak for an 1.4, and i have no idea how Sensitivity of the Two compares.
I gave it about any chance i could, Shooting with an 0,58x Metabones and an 50mm 1.4 Lens for an Effective Aperture of f/0,812 (=T/0,87) and with the IR-Filter Removed, to even capture that little bit more Light that would eat.
Shot at 2142fps at 6dB analog Gain and 12 or 18 dB Digital Gain, 354° Shutter. Obviously a ton of Motion blur because of that, but cant do much about that for Such Low-Light Shots that are just barely possible anyways.
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Regards your f/1.3 Prime Lens, you can try, but it was challenging at f/0.8 already, which is almost two full stops of Light more than your Lens, so dont expect anything close to those Phantom-Shots if you use that lens.
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#EDIT:
Forgot to add, this was shot on 5.1 Unstable Firmware also, to just get a brighter Image. Obviously more noise, but a bit Brighter than 6.0 at least, havent done a ton of testing still with 7.0.
/EDIT#
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Here is also an DNG, shot at 2998fps or whatever it is exactly, also same lens wide open as above, Maximum Shutter angle, and a ton of digital Gain. This is the Brightest Single Flash i was able to capture in one Frame in this short session when the hammer Smashed one of the Bits somewhere lower down.
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I really like the viewing angle. The whole Life Saver lights up where it's being hit. Really nice shot.
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Did like half a bag, and at some point ended up with that Backlit look, for the last few shots i wanted to make it look a bit more epic, so i choose a low, really close angle. Would have gone lower if could have, but the Lens was literally Hitting the Table already. I am Currently looking through all my other shots, saved pretty much every one i did, but this seems to indeed be the Best one of the Day, everything else is somehow not really worth sharing i feel like.
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So I shot a similar test with my full spectrum Sony A7S. I was not too concerned about slow motion since I will revist this with the Chronos which arrives tmw assuming no issues with fedex. Anyway the Sony A7S is very sesitive to low light. I ended up using a small IR flashlight and aimed it at my chest to act as a soft bounce and fill the area with a it more light. I used a F/0.95 35mm lens. I forget the ISO but I think it was at 6400? Amazed how bright this was.
https://www.instagram.com/p/CV4Zpm0LdyG/
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Well, could be, that most of the light isnt even visible, so an actual full-Spectrum Camera would ofc. capture a ton more Light.
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Hi...Assuming you need a high shade speed and blaze, you should adhere to the sync speed of the screen for streak, which I think for this situation is 1/200. Over that the image will not come out. (some more costly cameras have a higher speed setting, in which the glimmer beats. Not accessible here.) Because the blaze is such a ton more limited in term than the screen speed, precise speed is seldom too significant except if you're doing fill glimmer or utilizing an extremely low shade speed to get both surrounding light and blaze light. For activity, I question you'll see a lot of distinction between speeds.
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Hi also, you use a lot of words, i am not really sure about what they mean. "Shade Speed" is probably Shutter Speed? But what is "Blaze"? Not heard about anyone use that in Relation to Cameras yet, no idea what that would even mean here.
I also dont really know what you are trying to say about the 1/200 (which i assume Would be Shutter Speed in Fractional Seconds) and whatever that would then sync to, this is a pretty Dynamic Process we are Trying to capture here, not something like a Electronic Flash from a Camera.
If i understand you correctly, you are trying to say (among other things i am not quite able to follow you with), that shortest beneficial Shutter speed to use to capture this would be 1/200s and anything above that would not give you any more detail.
If that is the case, i can tell you, that this is in fact not correct, as in the linked Video they Clearly use Framerates like 28000fps (or even 50kfps in one of the Shots shown), which would only allow for an Maximum Shutter Speed of 1/28000s per Frame (which is WAY SHORTER!), and they can Clearly capture the Glowing Event that is happening there and even some environmental Light, and there is a lot more Detail to be seen, than i am Able to see at 1000fps or even 3000ish fps. (Also Motion Blur from Fast Moving Parts). A Maximum Shutter Speed of 1/200s Would however Limit my maximum Possible Framerate to 200fps or even Lower, and i can clearly capture This Blue Light Even with my Chronos 2.1 (be it with some Insanely Fast Lenses and very much extreme Settings, but its possible, as shown above), which is nowhere near as Sensitive to Light as those Phantoms they use there.
I maybe got this completely Wrong, you might be trying to say something about the Night Vision Thing or ....?
Not sure, if i understood you correctly, or what exactly you are trying to share or ask here? Please Elaborate.