Messages

31

Software Dev / Re: Chronos V0.3.2 Beta

« on: June 08, 2019, 05:39:00 PM »

Ran the camera on an older version and everything looked fine, updated and found the same black calibration issues, so here's what I found.

#0 It only happens at frame rates above ~27kFPS
#1 It gets 10x worse at 4x analog gain, at 1x and 2x the image is pretty good. At 16x I get only gibberish for an image.
#2 The flickering seems to be related, it is most apparent when the vertical banding is present. I haven't measured the period of the flicker yet to see if it is the same at every resolution/fps.

Below I have attached 4 images taken at the 320x96 40420.4fps 20.08us 4x analog gain (worst case scenario but the effect is very similar down to ~27Kfps. I let the camera warm up (it seems to do that a lot faster now, the fan ran at full speed since the update) before taking the images. I had to convert them to PNG because the forum didn't like .TIFF files made by the camera.

0th image is taken before doing a black cal and before doing the factory cal.
1st image is after a black cal but before the factory cal
2nd image is after the factory cal but before doing new black cal
3rd image is after the factory cal and after a black cal

Hopefully this is helpful.

32

Software Dev / Re: Chronos V0.3.2 Beta

« on: June 08, 2019, 01:28:02 PM »

I'm going to restore a known good version then try the update again. If I get the same results I'll make some example files for you.

33

Software Dev / Re: Chronos V0.3.2 Beta

« on: June 08, 2019, 09:17:47 AM »

Update was easy enough and I like the new storage Tab in the utilities.

Black cal at 1x works well but with any more than that I get significantly more banding than 0.3.1 at higher frame-rates. I'll keep poking around to see if anything I do can make it better or worse. I have also noticed that there is some flickering, at higher gain is is more visible but it can be seen at 1x as well.

I also had "No Batt" after the first restart but that has gone away, not really worried about it.

Sorry for all the negative feedback but I am still impressed at the work that is going into the 1.4 and I am glad you guys are still working towards more features!

34

Chronos User Discussion / Re: Chronos 1.4 Footage Thread

« on: May 18, 2019, 02:24:25 PM »

The DNG output and white balance fix make it way easier to get clear shots now.

https://imgur.com/lHNb8lC

35

Software Dev / Re: Saved file's owner/group/permissions.

« on: March 18, 2019, 05:55:41 PM »

Awesome! Thank you! I had some serious head-on-keyboard time and never noticed that the x was missing.

36

Software Dev / Saved file's owner/group/permissions.

« on: March 16, 2019, 04:15:18 PM »

I am using ext3 so I can save >4gb files but the permissions made by the camera are pretty wonky. Is there a way (even if it's a one off change I need to make to my own camera) so that I can change the user and group that the files are saved under? I'm reasonably familiar with Linux and don't mind making backups of my OS microSD in case I brick something.

If there is no easy way then no worries.

Thanks for your awesome work!

-Nick

37

Chronos User Discussion / Re: Infinity focusing in the dark

« on: March 15, 2019, 04:17:52 PM »

If you set your Chronos to 30fps you can increase the exposure enough to let you focus. After you set the focus put the framerate back up to what you intend to record.

38

Software Dev / Re: Software Roadmap - 0.3.1, 0.4.x, etc.

« on: March 14, 2019, 10:17:47 AM »

Glad to hear you guys are still plugging along, each update and rc has made the camera more enjoyable to use. Good luck at NAB!

39

Chronos User Discussion / Re: Chronos 1.4 Footage Thread

« on: March 03, 2019, 01:26:47 PM »

"Expose to the right" is your friend. In photography this means exposing your subject as bright as possible without blowing out the whites and then darkening it in post processing. It will let you crush the blacks to 0 while keeping detail in your subject. Unfortunately the only way to practically do this with video is with an absurd amount of light >_<

40

Chronos User Discussion / Re: Workflow - Time

« on: February 17, 2019, 07:24:15 AM »

I can't find it now but there is a thread that mentions using an external drive enclosure with an SSD that is powered by the camera. SSDs are pretty light on power requirements, I can't see why you wouldn't be able to use one.

41

Chronos User Discussion / Re: Chronos 1.4 Footage Thread

« on: February 15, 2019, 09:05:11 AM »

Very cool, I like the light guards on the mirror and viewfinder.

42

Chronos User Discussion / Re: Chronos 1.4 Footage Thread

« on: February 13, 2019, 06:46:35 PM »

A sub-sonic ping pong ball this time, getting ready for a maker fair. Filmed at 20kFPS

https://i.imgur.com/Z6dLawL.mp4

43

Software Dev / Re: Software Roadmap - 0.3.1, 0.4.x, etc.

« on: February 11, 2019, 12:45:35 PM »

Thanks for the update.

I am excited to see hear the HTTP API is coming along, you guys are doing awesome work!

44

Chronos User Discussion / Re: Let's talk LENSES!

« on: February 01, 2019, 01:51:51 PM »

The Fujinon 2.7mm F1.8

I wanted a really wide lens so that I could get a reasonable field of view when using higher frame rates and this lens looked like it would do the job. You can find this lens on ebay starting around 150CAD, there are some sellers that have it listed for WAY more than that, it's not worth that much. If you want one keep looking and wait it out until you can find one for 200 or less.

The Good:
-It's wide! If you are using the full width of the Chronos' sensor you will get a 180degree wide field of view!
-It's fast! F/1.8 means it delivers a very bright image, it captures a lot of light.
-It's small, around 50mm long which is bigger than most c-mount lenses but WAY smaller than the SLR lenses I use.

The Bad:
-Fixed focus, there is no way to adjust the focus other than using the backfocus on the Chronos, you'll need to keep an allenkey.
-It's a little soft, being an F/1.8 it is a little soft but I didn't find it any worse than the other c-mount lenses I use.
-The price, brand new (with the adjustable aperture) it seems to go for 400 CAD and up, hold out for a used one on eBay if you can.
-Image circle, when using the full Chronos sensor the image circle doesn't entirely fill the frame, but given the field of view it's not a huge problem.


Setting the backfocus can be a little finicky, I found it was best to set the Chronos to a small crop (128x128 ish) and then adjust the focus. My copy came with a weird cap/adapter and 2 very thin plastic rings, adding just one of the rings will take the focus from infinity down to 1m or less, this lens is VERY sensitive to changes in distance between the lens and the sensor. Overall I am impressed, it's well built and despite being a little soft it more than makes up for it by giving a 180 degree field of view. For reference, in the last photo the lens is touching the glass of the window and yet you can still see the edges of the frame.

45

Chronos User Discussion / Re: Workflow - Time

« on: December 23, 2018, 01:13:47 PM »

Are you using the SSD in a USB enclosure or eSATA?

Currently I am using a 128gb USB thumb drive that is ok but not great.