Author Topic: New to Chronos 2.1 questions  (Read 492 times)

paulrossjones

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New to Chronos 2.1 questions
« on: June 20, 2019, 07:32:48 PM »
hi, I don't know very much about the new Chronos, but it seems like quite a camera.

A while back I was keen to buy an old slightly faulty (that needed to be continuously connected to a laptop to work) 2k phantom that was eBay a year or two ago, but the price it ended up going for was 10k if I remember.
Looking at the specs of the phantom, the chronos is not completely out its league. sure the old phantom does 2000fps and has a super 35mm sensor, but the chronos 2.1 Can use a Speedbooster for the s35mm look, which will turn its Base ISO to 1600, and its less than a 1/4 of the weights, and only is 5k usd new. It shares the same dynamic range of 10 stops - same as the phantom.

Can someone help me with these questions?

1/ do you have to trigger the camera at the start of an event, or can you trigger after something happens? Ie like the Sony fs700? It is very useful to trigger after when you have something happening and you cant predict!

whoops, I can answer this, I didn't realise there was a second page to the tech PDF!

2/ Is there any samples of DNGS from the camera so I can see what the footage grades like? You tube doesn't quite do the footage justice.

3/ Can the camera be used as a normal camera when shot at reasonable frame rates, ie 24-30 fps?

yes, I have found the answer

4/ After the camera has been triggered- say for the 5 secs it records, with a very fast SD card, how long wouldI be expected to wait for 5 secs of 1080p DNGs to copy over? I know you guys may not have the camera, but someone who has the older camera kind of know- is the expected wait going very painful? will it 30 sec's or many minutes?

5/ I know there is some talk in some posts about a micro 4/3rds mount, is this available, or do I need to adapt from c-mount somehow? I would be keen to use a 0.64x metabones with canon full frame glass. What exactly is c-mount? an old screw in mount?

6/ What output is available for monitoring with an external screen? There's HDMI- but what does this output? 1080p? The screen on the back is not enough res to really work and focus easily.

7/ Does anyone make a cage for this to mount accessories?

Thanks for any answers, cheers Paul
« Last Edit: June 20, 2019, 07:39:29 PM by paulrossjones »

skronstein

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Re: New to Chronos 2.1 questions
« Reply #1 on: June 21, 2019, 08:51:10 PM »
2/ Is there any samples of DNGS from the camera so I can see what the footage grades like? You tube doesn't quite do the footage justice.
Here is some footage from aaronkondziela: https://www.dropbox.com/sh/1udpw4u6zs3sgeq/AADhYb-k_7OORKui9Q94CkLDa?dl=1
details about the footage in this post http://forum.krontech.ca/index.php?topic=271.msg1859#msg1859
and grade of that footage was linked here: http://forum.krontech.ca/index.php?topic=271.msg2206#msg2206

4/ After the camera has been triggered- say for the 5 secs it records, with a very fast SD card, how long wouldI be expected to wait for 5 secs of 1080p DNGs to copy over? I know you guys may not have the camera, but someone who has the older camera kind of know- is the expected wait going very painful? will it 30 sec's or many minutes?
If saving the whole 5 seconds, it will take more than half an hour to save the entire buffer of a 16GB camera. The Chronos 1.4 saves 1280x1024 CinemaDNG files at about 3-4fps, and RAW 12-bit packed format at 4-5 fps.  If saving in RAW 12-bit packed, the file will be 3/4 the size of either CinemaDNG, and the file can be converted to a set of DNGs using our python script: https://github.com/krontech/chronos-utils/tree/master/python_raw2dng
If you want to save only portions of the video to save time and storage space, it's easy to scroll through the footage on-camera and select a region to save.  You can come back to the camera after it's done and save more regions too.

5/ I know there is some talk in some posts about a micro 4/3rds mount, is this available, or do I need to adapt from c-mount somehow? I would be keen to use a 0.64x metabones with canon full frame glass. What exactly is c-mount? an old screw in mount?
7/ Does anyone make a cage for this to mount accessories?
We don't have an accessory cage or micro 4/3 mount or adapter available at this point. C-mount is a screw in mount.
Nikon1 seems to know a lot about lenses, so he may be able to help. http://forum.krontech.ca/index.php?topic=464.msg2481#msg2481
AimedResearch has made MFT mounts, but he hasn't been on the forum for a while. http://forum.krontech.ca/index.php?topic=97.msg802#msg802

6/ What output is available for monitoring with an external screen? There's HDMI- but what does this output? 1080p? The screen on the back is not enough res to really work and focus easily.
Video output is 1080p if the display supports it, or 720p if not.
« Last Edit: June 21, 2019, 08:53:21 PM by skronstein »

paulrossjones

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Re: New to Chronos 2.1 questions
« Reply #2 on: June 22, 2019, 06:02:13 PM »

If saving the whole 5 seconds, it will take more than half an hour to save the entire buffer of a 16GB camera. The Chronos 1.4 saves 1280x1024 CinemaDNG files at about 3-4fps, and RAW 12-bit packed format at 4-5 fps.  If saving in RAW 12-bit packed, the file will be 3/4 the size of either CinemaDNG, and the file can be converted to a set of DNGs using our python script: https://github.com/krontech/chronos-utils/tree/master/python_raw2dng
If you want to save only portions of the video to save time and storage space, it's easy to scroll through the footage on-camera and select a region to save.  You can come back to the camera after it's done and save more regions too.



Thanks for all the answers!

I am trying to imagine a practical scenario I would shoot - say a splash, many times and not take too long between takes. I am not use to very high frame rates (only really up to 120fps), so I guess at 1000 there's 200secs of footage for a 5 sec take(played at 25fps). when you only really need 10 secs a lot of the time when played back.
So would it be a case of shooting multiple takes and editing/cutting/selecting the footage off the ram inside the camera and storing only the "select" part of the event, then running another take with the available free space on the ram? If so, buying the camera with the largest ram would be the most useful?

Would it be easy to play the take and cut it down off the camera between takes?

Usually setups for between anything you want to slow down takes a bit of time to reset, so there is spare time to cut and throw away the unused parts of the footage, but probably not 30minutes worth!

Thanks again, Paul





skronstein

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Re: New to Chronos 2.1 questions
« Reply #3 on: June 24, 2019, 03:30:32 PM »
When starting a new recording, the previous one is replaced.

However, you can use the Segmented recording mode, where a fraction of the total buffer is allocated for a each segment. Each time the camera detects a trigger, a new segment is recorded. You can set any number of segments you like. A camera with twice the amount of RAM can record twice the number of segments, or segments twice as long.

The other exotic record mode is Gated Burst, where the only frames that are stored in RAM are the ones while the trigger is pressed, and shortly before it is pressed (called prerecord time, which is also configurable)

Currently, only external triggers can be used, meaning a pushbutton trigger or a signal generator.  We plan to have the red shutter button on the top of the camera to be usable for these modes too.