KronTalk

Chronos => Chronos User Discussion => Topic started by: evanh on September 22, 2018, 02:42:01 AM

Title: Moonlit stills, Chronos suitable?
Post by: evanh on September 22, 2018, 02:42:01 AM
I'm no optics expert but I get the impression the Chronos has a high sensitivity image sensor.  It stands to reason this could work in moonlight for stills or even ordinary speed video.

For comparison:
I've previously used a Canon S5, 2002 model, for some low-light work and it does work for stars in the night sky but I couldn't get it to pick up anything non-transmissive in a just-after-dusk shot.

PS:  I do want a high speed camera as well.  The Chronos monochrome model would seem the right option to cover both jobs.
Title: Re: Moonlit stills, Chronos suitable?
Post by: NiNeff on September 22, 2018, 12:14:50 PM
I've not yet tested filming at night (something like the stars), but you can indeed st the frame rate very low. I believe it was about 10s max exposure per frame. (You can search it on the forums here, telsa500 posted it somewhere ;))
However I don't think using a high speed camera is a good idea for low-light situations. It might work and you might get some useable results, but your effectively wasting money and computing power on the exact opposite kind of features you're using.

But using the camera as dual-purpose might work. I'll try to do some test shots in the coming weeks or so.
Title: Re: Moonlit stills, Chronos suitable?
Post by: Nikon1 on September 22, 2018, 02:57:24 PM
Given that you can get your hands on (or even own one) a Lens With 300mm or more, good Sharpness and a somewhat big apperture or even a Telescope you should be able to get good shots of the moon. Since the moon is quite bright, you could actually maybe even get real-Time Video from the chronos. I still dont own one, so dont take my word for it... But if you could do exposures of up to 10 Seconds, and the moon beeing quite bright, you should get enough light with it.
For stuff like Stars ist a bit of an different story. Since the Chronos is rather low resolution compared to modern Digital Cameras you wont get a ton of stars/ details to see in your images. Unless you have some impressive Telescopic optics to pair with the Camera. But if you already have the Optics, then why use the chronos for star Photography? Almost any Camera will take good pictures of the night Sky if paired with some Impressive Telescope. There are a lot of "better" alternatives than the Chronos for stills, meaning Cheaper and Higher Resolution. Just to name Some Alternatives with "small" sensors of variying size: MFT-Cameras like Pansonic, Olympus; the Nikon1 System; Pentax Q; Modified Gopros and of course Various Industrial C-Mount cameras (which could also qet realy pricey quickly)... and of course Hacked Compact-Cameras (some of them are super inexpensive and still have a good sensor inside, lens removal could be difficult sometimes.).
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If you mainly want the chronos for highspeed, then it is in my opinion the best option you could get around this price range. It should be usable for night photograpy and would have the advantage that it gives you a LOT of fine Control over stuff like framerate and exposure time, which you wont get in any usual conumer-grade Camera. This could be a really powerfull camera if you are into some super advanced (in terms of timing) timelapse-stuff. But like said, the resolution is not super high.
If you want it primarily for stills, then there maybe be some better option for you. If you want the 2/3" sensor size, there are Plenty of other cameras with similar sensor size, that will work as well and give as good or even better results than the Chronos, some at way lower price points. Have a look into the above List of cameras or look into industrial c-Mount Cameras with CCD-Sensors.
If you want ultimative Night-Vision in a Camera just Get an Sony A7 Sii or S. There are some other Big-Sensor - High sensitivity Cameras out there, but Sony does it best at the moment with the A7Sii. About the same price of the Chronos and you will also get a lens to that A7 for this kind of money... Bad thing is that the A7s just does quite lame framerates...
Title: Re: Moonlit stills, Chronos suitable?
Post by: evanh on September 22, 2018, 05:50:38 PM
NiNeff,
Any examples of lighting sensitivity of the surroundings will be appreciated.  Shadows cast by the moon would be an example.

I know the resolution ain't great but buying a specific camera for the job won't happen.  It's the Chronos or naught.  The Chronos will be used for its designed purpose also.

Title: Re: Moonlit stills, Chronos suitable?
Post by: BiduleOhm on September 23, 2018, 07:24:39 AM
Actually if you use the mode where the trigger controls the shutter you should be able to do really long exposures, far more than 10 seconds AFAIK.
Title: Re: Moonlit stills, Chronos suitable?
Post by: Nikon1 on September 23, 2018, 07:35:42 AM
Actually if you use the mode where the trigger controls the shutter you should be able to do really long exposures, far more than 10 seconds AFAIK.
ok, didnt think about this one... This is an VERY interresting Idea!
What would be limit for the exposure then, using this methode? If there is no Limit, then you could do exposures for almost forever... Should Work very well for super-Long Astro- and Night-Exposures!
I think something like 30 Minutes exposure for a single Frame is the Limit for some of the High-End DSLR´s, have not seen more on an DSLR or DSLM or alike, so this would be an seriuos usecase for the chronos.
Now that is something the Chronos does much better than most other today Digital Cameras (apart from special cameras for Industry and Astro-Use).
Title: Re: Moonlit stills, Chronos suitable?
Post by: BiduleOhm on September 23, 2018, 08:36:20 AM
Unless there's something I missed there shouldn't be any limit (new crazy idea: make a photo with an exposure of weeks or months...). I think the first limitation would be software crashes but the Chronos shouldn't have this problem even for multiple days exposures.

But you'll need a very good mount to track what you want with no smearing.
Title: Re: Moonlit stills, Chronos suitable?
Post by: Nikon1 on September 23, 2018, 09:29:54 AM
Unless there's something I missed there shouldn't be any limit (new crazy idea: make a photo with an exposure of weeks or months...). I think the first limitation would be software crashes but the Chronos shouldn't have this problem even for multiple days exposures.

But you'll need a very good mount to track what you want with no smearing.
I dont think mounting is that big of an problem. There are some good Star-Tracking Mount you could built on your own and get solid results, even with high-Resolution-DSLR´s. And there are enough commercialy available also. And you could always just mount it on an solid Tripod and dont move it at all for everything else not involving Star- /Sattelite-Tracking.
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I think you will run into problems with your exposure way bevore you get problems with an (reasonable good) Mounting Solution, if we talk about Deep Sky and Astro-Tracking.
Light pollution of the Sky and all that stuff...
At some point you will just overexpose your image because of ambient light sources.
That is also the Reason why they would take a lot of single exposures (which still could be several minutes or even hours long) and Stack them /interpolate them in Software to get more detail out of it.
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You COULD expose for whole days or even longer with a camera however, but then you need a lens with a super small Apperture, some realy dense ND-Filter (Or stack some Up), a sensor with super low light sensitivity, or a place to Photograf with almost no light at all.
Thats were you get into Pinhole-Lens-Territory...
People have done stuff like that and did exposures of multiple weeks on an simle sheet of plain white office paper with an pinhole. The Sun in frame and all the light beeing projected all the time trough the lens onto the paper will "Burn" /bleach the image into the Paper and it will remain visible. Look it up if you want to. Also its quite common for Large Format Photography to use Appertures Like f/64, f/128 (and the Film in the Camera is also not very light sensitive...) combined with exposures of many minutes up to hours.
But for the chronos, i think it might even have an sensor too sensitive for such long exposures, if we are talking stuff like Landscape photography.
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IF you could make it work in terms of getting an properly exposed image (not overexposing) with that kind of exposure-Times per Frame, then it should be able to make even Day or Week-Long exposures :)
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I seriously never thought i could get hyped by the idea of using an highspeed-camera for timelapse, astro- /night-Stuff and Pinhole Lenses, but this is just an crazy cool idea.
Now i realy want to see someone push the exposure time to the limit for some Long Exposure stills. Should be an phenomenal Camera for Night timelapse and Hyperlapse then, because of the absolutely free defineable shutterspeed and framerate :)
Title: Re: Moonlit stills, Chronos suitable?
Post by: BiduleOhm on September 23, 2018, 03:41:59 PM
There are some good Star-Tracking Mount you could built on your own and get solid results, even with high-Resolution-DSLR´s.

Yes, arduino and raspberry pi are making things like that pretty easy now.

People have done stuff like that and did exposures of multiple weeks on an simle sheet of plain white office paper with an pinhole. The Sun in frame and all the light beeing projected all the time trough the lens onto the paper will "Burn" /bleach the image into the Paper and it will remain visible.

I didn't know this method existed, very interesting, thanks for the info :)

I seriously never thought i could get hyped by the idea of using an highspeed-camera for timelapse, astro- /night-Stuff and Pinhole Lenses, but this is just an crazy cool idea.

Yep, I thought about doing timelapses with the Chronos because you can do interesting/weird things like non-regular intervals for example (and I love the irony of doing a really slow thing with a very fast camera... ;D), but I never thought about astro-photography.

Title: Re: Moonlit stills, Chronos suitable?
Post by: dindindy on September 23, 2018, 08:26:22 PM
 For low light filming, this camera is more suitable!

Another funny stuff from Kickstarter n_n!

https://www.kickstarter.com/projects/189168434/aurora-worlds-1st-day-night-camera-with-true-night
Title: Re: Moonlit stills, Chronos suitable?
Post by: Nikon1 on September 23, 2018, 09:39:54 PM
For low light filming, this camera is more suitable!

Another funny stuff from Kickstarter n_n!

https://www.kickstarter.com/projects/189168434/aurora-worlds-1st-day-night-camera-with-true-night
If you want ultimative Night-Vision in a Camera just Get an Sony A7 Sii or S. There are some other Big-Sensor - High sensitivity Cameras out there, but Sony does it best at the moment with the A7Sii. About the same price of the Chronos and you will also get a lens to that A7 for this kind of money... Bad thing is that the A7s just does quite lame framerates...
Yeah, i talked about that bevore. I dont know that kickstarter, but just judging by the rather Low price of that kickstarter Camera and a Quick look at the Size there, i would guess a Sony A7Sii would Still outperform it easily in terms of Super Low-Light Video. Could be wrong about this. But the Next Generation, the A7Siii is about to come out at some Point and should even improve Low-Light video in this camera. So if you need/ want ultimative Low-Light Performance, just buy any A7S of your choice.
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And i totaly get, and know, that there are way better Cameras for normal-Speed Video in Super-Low-Light Situations than the chronos, but we are talking single Image Photography and very Extreme Timelapse stuff here...
Ist not like it was the most Light-Sensitive Camera around, but like we found out earlier in this post, you should, in theory, be able to basicaly expose single images forever if you wanted. And that opens up a whole World of possibilitys, because Like i wanted to proove by coming up with that office-Paper-Pinhole-Camera earlier, you could take a picture with even Not-Super-Light-Sensitive Stuff (or Cameras) if you expose your image long enough.
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Other thing: Would be actually interresting how the chronos would perform for Normal-Speed Video in Bad light, but my strong guess would be that it would not hold up too well against even an Average modern DSLR/ DSLM given the 2/3" sensor in the Chronos compared to the Way bigger Sensors of FullFrame, DX/ APS-C and MFT-Cameras. Even the new Sony 1" BSI-Sensors for their RX100-Series getting better every time. But i could also be wrong about the chronos here, and maybe its an Low-Light Monster... Who knows?
Title: Re: Moonlit stills, Chronos suitable?
Post by: Nikon1 on September 23, 2018, 09:50:10 PM
so, just did a Quick Search on Yahoo Images "Pinhole photo sun paper" and there You will find tons of stuff about crazy long exposures.
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http://www.riledupjournal.com/RiledUp/TabId/166/ArtMID/558/ArticleID/500/Antiquarian-Skylight.aspx
This one, the first good one, that i found, they used a 6Month long exposure on that pice of special Photography Paper-Film. I once came across someone doing someting quite similar with normal office paper, but i could not find it right now. Just look it up, funny stuff.
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And that is the Point about the chronos, You could (or should be able to) do stupid long exposures with it, which is rather rare for about any digital Camera apart from very special ones.
Title: Re: Moonlit stills, Chronos suitable?
Post by: DDR on September 27, 2018, 08:16:23 PM
From what I've heard — and this is second-hand, since I've been dealing mostly with the user-interface software here rather than the hardware — the sensor in the Chronos is a bit weird. The longer the exposure time, the noisier the results from the sensor. IIRC, after half a minute of exposure the resulting picture is effectively gone. Something in the physics of it accumulates errors over time, rather than averaging them out like in a normal sensor.
Title: Re: Moonlit stills, Chronos suitable?
Post by: Nikon1 on September 27, 2018, 08:52:03 PM
From what I've heard — and this is second-hand, since I've been dealing mostly with the user-interface software here rather than the hardware — the sensor in the Chronos is a bit weird. The longer the exposure time, the noisier the results from the sensor. IIRC, after half a minute of exposure the resulting picture is effectively gone. Something in the physics of it accumulates errors over time, rather than averaging them out like in a normal sensor.
Thats nothing unheard of. Most Digital Sensors produce Lot of noise. Thats why you will find tons of Astro-Guys modify their Cameras with special cooling for the Sensor. Some of them even go sub-zero and seal the Inside from Air to not get condensation. I think the Sensor is not specialy bad or weird in terms of noise to signal ratio, but because you would normaly pull massive framerates from it, i guess it runs "a bit Hot" in comparison to "normal" DSLR Sensors & CO. And that is completely fine for what it is intended to do normaly, Highspeed video.
So Cooling it down to a point just bevore you get condensations of Water on the Sensor would be worth a try if someone realy wants to pull crazy long exposures from this camera.
Title: Re: Moonlit stills, Chronos suitable?
Post by: NiNeff on October 16, 2018, 11:32:41 AM
I did some tests now using 10 fps as the "long" exposure which is still really short compared to the usual seconds or minutes normally used for astrophotography or videos.
The Chronos is not suitable at all for this task.
See the attached still of the moon. The noise is not some sort of JPEG-artifact but inherent to the camera. I tried my best to let the cam warm up and did a black cal just before this shot.
Also, here's a really blurry video of mars taken also at 10 fps:
https://youtu.be/g-L_JynwLPc
Title: Re: Moonlit stills, Chronos suitable?
Post by: Nikon1 on October 16, 2018, 11:41:50 AM
Thanks NiNeff for trying and Posting that.
I guess DDR is Right, too much noise.
If the Camera would be stupid cheap like around 100$, it would be worth try modify it and Cool the Sensor down really cold. that COULD help somewhat with the noise. But at that price point i wouldnt risk that.
I guess you CAN get something remotely "useable" form it in such low-Light-Long-Exposure Situations but nothing really super high Quality.
But since it is not intedended for anything like this, i am Not surprised at all with exposures that long.
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Keep in mind that your usual DSLR or astro-CCD-Camera on the other hand can´t even remotely touch the 1000+++ fps of the Chronos but will perform Better in Low Light /Crazy Long exposure :)
There is an tool for every job!
Title: Re: Moonlit stills, Chronos suitable?
Post by: BiduleOhm on October 16, 2018, 02:39:21 PM
Well... with a lot of averaging (like hundred of frames) it's maybe possible.

I guess the thing is as the sensor is very sensitive you don't need the multiple seconds exposure (as your test at 10 fps proves it) so you can do a lot of shoots in a relatively short amount of time and average them to have a better SNR. I'd say to also test at a higher framerate (something like 20 or 30 fps for example) to see if it improves things, or not... (I don't know if the SNR is the same at 10 fps and 30 fps so I guess only a test will answer that).
Title: Re: Moonlit stills, Chronos suitable?
Post by: tesla500 on October 16, 2018, 04:44:34 PM
The noise you're seeing here is actually just dark noise. Black cal won't work below about 60fps, so what you're seeing is an uncalibrated image. Try doing a black cal at 60fps then changing to 10fps.
Title: Re: Moonlit stills, Chronos suitable?
Post by: Nikon1 on October 17, 2018, 03:01:28 AM
@tesla500
Ok, that is good to know.
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@BiduleOhm
Well, the moon is actually quite a bright object in the Sky. If you want to do some deep Sky-Object Photography you will have to deal with far less bright objects in the Sky.
Also i guess that image of the moon was shot on the Kit Lens @75mm...? Based on the Size... Dont know what apperture tho, could be anything from 1.2 (Rather unlikely that NiNeff used 1.2 on that) to like 11...?
As far as Sensitivity of the Sensor goes, i found in side-By-Side testing with my Nikon1 that the Base-Gain (Gain 0) is about as sensitive as ISO 160 or 200 and the highest available Gain-Setting should be compareable with ISO 3200 as far as Sensitivity goes, but i havent tested that side-By-Side for the higher Gain-Values for verification.
While it is possible to use 1.2 on something like the Kit lens, if you want something longer (Like Telescopes), you will get appertures of 5,6 or below. Also most Lenses Wont perform best when wide-Open, so you will need to Stop most of them down a bit to get good image Quality. And if you simply expose your image Longer then, i guess Noise will get even Worse.
Title: Re: Moonlit stills, Chronos suitable?
Post by: Sael on October 17, 2018, 03:15:15 AM
While not suitable for it, decent results can be gotten from the Chronos. Because the noise gets worse as you below 60FPS that's the lowest I went. The lens is a Tamron 150-600mm F/5-6.3. Video recorded at 600mm F/6.3, Moon at 60FPS, and mars at 500FPS.
Title: Re: Moonlit stills, Chronos suitable?
Post by: BiduleOhm on October 17, 2018, 03:57:18 AM
Wow, mars is pretty decent for a camera who wasn't designed to do this, especially at 500 fps.
Title: Re: Moonlit stills, Chronos suitable?
Post by: Nikon1 on October 17, 2018, 04:24:39 AM
I downloaded the Video from the moon now 3 times but cant open any one of them... Dont know what that is all about. Maybe just my bad internet connection here.
But the Mars one is actually pretty impressive.
If the Noise gets so much worse below 60fps, then maybe just use 60fps or faster i guess...
Title: Re: Moonlit stills, Chronos suitable?
Post by: BiduleOhm on October 17, 2018, 04:35:51 AM
I was able to open and play it with VLC without any problems.
Title: Re: Moonlit stills, Chronos suitable?
Post by: Nikon1 on October 17, 2018, 04:44:19 AM
I was able to open and play it with VLC without any problems.
I tried again, and now i can open it. The other 3 Downloaded Files from the Same Video wont open in VLC or in AE CS6
While the noise is still quite strong for my taste on this shot with the moon, all things considered its still rather impressive for an camera which wasnt meant to do anything like this, especialy with the mars one at 500fps.
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@Sael:
What Gain settings did you use on those? Propably Base-Gain (0) for the moon, but it propably has to be an higher Gain-Setting for the Mars one at that framerate?
Title: Re: Moonlit stills, Chronos suitable?
Post by: NiNeff on October 17, 2018, 09:31:00 AM
The noise you're seeing here is actually just dark noise. Black cal won't work below about 60fps, so what you're seeing is an uncalibrated image. Try doing a black cal at 60fps then changing to 10fps.
That's actually what it did. I first did a blackcal an then changed the FPS. as it was very bad, I did a second black cal at 10fps with no improvement, obviously.

@nikon 1: I don't remember the f-stop settings, but it was very closed. the exposure time was also way down to about 1% The moon is indeed very bright.

@Sael: that mars video is actually really good, I guess you're using a magnification of about 250x to 300? Now I'll definitively need to hook up my telescope to the Chronos just for the fun of it
Title: Re: Moonlit stills, Chronos suitable?
Post by: Nikon1 on October 17, 2018, 11:20:29 AM
@Sael: that mars video is actually really good, I guess you're using a magnification of about 250x to 300? Now I'll definitively need to hook up my telescope to the Chronos just for the fun of it
You could try just using Some Old Paper-Core from Toilet Paper or alike and A bunch of Tape for an Adapter if you want to go really ghetto and cheap with the adapter. Just cut it down to about the right Length and make sure you secure the Camera, so it wont drop down...
If you are patient enough and want to spend the Money there Should be Canon to C-Mount Adapters somewhere...i think?
Title: Re: Moonlit stills, Chronos suitable?
Post by: Sael on October 17, 2018, 06:36:57 PM
@Nikon1 6 or 12dB, I don't remember... I did abuse levels correction to hide noise however, because it's a black background with a bright object you can crush the shadows and hide a lot of the lower intensity noise. Attached is an example without the crushed blacks. Nikon to c adapters and Canon to c adapters are available on ebay for ~$40-$60CAD.

@NiNeff 600mm on a ~4x crop makes for ~2400mm 35mm equivalent. "magnification" doesn't really make much sense in the photography world unless you have a reference point. Some camera lines use a times zoom, but that's relative to the widest view of the camera. The field of view of a lens is mainly dependent on the focal length and the sensor size. A 50mm lens on a 35mm "Full Frame" sensor (arguably the most common lens and format in the film days) has about a 40 degree FOV, 600mm on a full frame is about 3.4 degrees, and with the size of the sensor on the Chronos it would be about 0.85 degrees. I guess that would be 47x then? Or 4x compared to the widest the lens goes... (150mm)
Title: Re: Moonlit stills, Chronos suitable?
Post by: NiNeff on October 18, 2018, 09:49:41 AM
I was using Magnification in the sense most Binoculars are displaying it. But actually I don't quite know how that is specified then. Googling reveals "an object viewed through 10x magnification glasses appears 10x times closer" which is not the same as 10x larger one might think. Also I have a feeling there's quite a bit of marketing involved so not really a good measure.
Title: Re: Moonlit stills, Chronos suitable?
Post by: Splaccut on September 06, 2023, 08:20:03 PM
sonic exe (https://sonicexe.io)
I'm no optics expert but I get the impression the Chronos has a high sensitivity image sensor.  It stands to reason this could work in moonlight for stills or even ordinary speed video.

For comparison:
I've previously used a Canon S5, 2002 model, for some low-light work and it does work for stars in the night sky but I couldn't get it to pick up anything non-transmissive in a just-after-dusk shot.

PS:  I do want a high speed camera as well.  The Chronos monochrome model would seem the right option to cover both jobs.
If you're specifically looking for a high-speed camera that can also handle low-light photography, the Chronos monochrome model could be a suitable option.