Messages

16

Chronos User Discussion / Re: Focusing Troubles

« on: October 03, 2017, 06:00:10 PM »

Once the option to zoom in returns that will be handy and will make things easier.
Until then, I've found putting a card/piece of paper with some sharp black/white text or lines against the subject, focusing that and then doing the shot works for me. But that isn't always possible.

17

Chronos User Discussion / Re: Segmented buffer?

« on: September 24, 2017, 01:27:31 AM »

Of course. It doesn't start recording at once, just gives the ready to record screen. So you can choose to wait for the save or hit record again.
I would imagine the interface shows  'Seg mode: 6.2s ava. *Saving 94% done*.'
I'm not sure. It would depend on how much space the final interface has. A spinner is a good idea.

On a related note, I wouldn't mind a 'your buffer is' display on the recording setting screen so playing with frame-rates/res shows how much time you have.

18

Chronos User Discussion / Re: Segmented buffer?

« on: September 22, 2017, 07:26:48 PM »

I got the impression that segmented memory was a planned feature and I believe it was going to operate like that, or something close.
Better still could be a more sophisticated version..

Mark in/out hit save and only /that/ segment is notched out of the buffer.  So if you mark out 2 seconds, then you'd get record time minus 2 seconds.
Depending on implementation, this could be done a few times, up to say, 4 times. With each marked-and-saved segment queued for saving in the background.
(Memory would be freed up each time you hit record. So you wouldn't get it back the moment the save is done)

19

Chronos User Discussion / Re: Filming a welder?

« on: September 21, 2017, 10:39:09 PM »

I'm informed that even high levels of IR won't get past the lens and damage the camera and if your lenses are made from soda lime glass then this will also work for UV,
https://en.wikipedia.org/wiki/Ultraviolet#Blockers_and_absorbers

I'd follow the standard rule, make sure the camera is half a meter or more away with a 10mm thick polycarbonate shield (Good idea anyway due to splatter/fumes/'no molten metal in camera' rule,etc)  you should be fine..  Remember that you can actually safely watch a welder if your more than a few(Like 4-5) meters away due to the inverse square rule(Not recommended, you'll still have minor vision bleaching but you won't have any damage for short amounts of time).

I plan to do a similar thing sometime over the next few months and this is what I'm planning on doing.

20

Chronos User Discussion / Re: [CLOSED] Pre-orders shipping yet?

« on: September 21, 2017, 06:06:22 AM »

So are there any shots of The Backyard Scientist's camera after you got it back?  Was the damage just on the main board or did it damage other things too?
(And for those who haven't seen: https://www.youtube.com/watch?v=9UYe8mxqKOM 

21

Chronos User Discussion / Re: Let's talk lighting

« on: September 18, 2017, 12:30:13 AM »

At least for smaller areas, a friend borrowed my camera and their lights were two or three 25 and 40W  LED 'spot lights'.. The kind with a grid of 3W LEDs each with their own lens. They are fairly cheap, waterproof(Not always a worry) and because they have a narrow beam, you can get a lot of light on a subject, at least up to about 8-9k fps and from a distance of about half 30cm to half a meter.
And at least at half a meter, the 40W 30 degree 'spot' outperforms my 100W  120 degree LED flood.

Huge powerful LED floods are great if you have large subjects or large splatter areas(Upside down mowers in your garage are a good example. but if your subject is fairly small, you can get away with a lot less light if you have good focus.  Or you can take a lot of light and make it much brighter...

22

Chronos User Discussion / Re: How to manually set the fps?

« on: September 16, 2017, 02:13:50 AM »

I.. didn't even think to try that.. I was hoping to use lower than full sensor bandwidth to give long record times to ethernet/esata.. But I didn't even think to try it just writing to main memory..

On my 4s camera, 800x600, at 1000fps..  I get 11.4 seconds of record time.   Brilliant!

This needs to be in the manual!

23

Chronos User Discussion / Re: Best Save-As frame rate?

« on: September 13, 2017, 12:47:49 AM »

Mostly, it doesn't matter. There are utilities in other threads to change the frame-rate as it's 'just a number'.  (1000frames per second record is still 1000 frames, regardless of if you play back at 30 or 60fps, just at 30fps it's twice as slow than at 60).  Your final framerate of your edited video is what will set the actual speed.
I tend to save and edit in 30fps just to make the footage last longer and because I can't tell the difference, plus speeding up or slowing down is easy to do in the editor and I record everything at that.
However experienced youtubers who have experience may have a different view because of something I just haven't encountered yet.

24

Chronos User Discussion / Re: Need a tutorial on shutter speed

« on: September 12, 2017, 07:20:46 PM »

I know it's been linked elseware. But this should be a 'must watch' video for owners of High Speed Cameras:
"The Challenges of High-Speed Filming" by SlowMo Guys:  https://www.youtube.com/watch?v=_lZvF-YyP0s

And David:  If there is space on the screen you could do   180°(50%)   as the shutter display and make both happy.
Edit: I would be tempted to put the shutter to 50% by default, except the Chronos seems to have less motion blur than the Phantom. But maybe I'm seeing things? (or not seeing them)

25

Chronos User Discussion / Re: Chronos 1.4 Footage Thread

« on: September 12, 2017, 07:13:13 PM »

I'm assuming the popcorn is in a pan? And it's not just being cooked by the lights?
(Played with some focusable studio lights myself, ended up boiling the water in the tray I was dropping things in, so I'm not going to rule things out.)

26

Software Dev / Re: "Missing" the out point when saving.

« on: September 08, 2017, 02:21:33 AM »

In a previous post:  http://forum.krontech.ca/index.php?topic=26.msg164#msg164
Tesla_500: "The SD interface is limited to 48MHz @ 4-bit, so cards above 24MB/s are of no benefit. I've had good luck with normal class 10 cards (10MB/s). Higher speeds may be beneficial later when RAW saving is available, but there doesn't appear to be any benefit for compressed saving, except maybe if you turn the bitrate up very high."

So I made sure I got 40Mb/s + cards. (The common speed up from that point).

What I'm /really/ curious about when it comes to writing out raw data.. Is this RJ45 connector on the side that has some kind of high speed twisted pair interface that can handle rather a lot of data?   (Or even the esata interface in a pinch) Maybe directly off the sensor, trade off resolution/fps for external storage?    1000fps,  800x600(or lower).. But writing directly to disk, rather than the RAM buffer?
But that is just me dreaming for now.

Edit: I've said it to David and I'll say it here. It's very nice knowing /why/ each limitation exists.  In this case, it's 'because the interface maxes out at that  speed'. Not 'Oh, we thought you'd buy the next version if we capped it there'.  That it's a hardware limitation, not a software one. Makes each one, while sometimes frustrating, understandable.

27

Software Dev / Re: "Missing" the out point when saving.

« on: September 07, 2017, 11:02:36 PM »

As far as I know, the camera only has a USB 2.0 port. Without knowing internals of the processor, USB should have better throughput than SD,  However the big limitation seems to be the encoder and I seem to recall much over about 12Mb/s(I'm likely wrong.) won't make any difference. My 80Mb/s cards write no faster than 40Mb/s ones. 

USB drives have hugely different write speeds and it's not as well documented as on SD cards.  I've got old USB 2 drives that write faster than huge but slow USB 3 drives(They /read/ fast, but write is bad). There should be utilities/benchmarks out there to test them, but you'll need to find one for your platform.

28

Chronos User Discussion / Re: trigger cable for IO1 (BNC)

« on: September 05, 2017, 06:14:41 PM »

After a depressing amount of research it turns out most '75 ohm' cables are actually 75 ohm coax with 50 ohm connectors. I was worried about compatibility as how the insulation and center/shield ratios are different. I believe the connector on the camera is 50 ohm specked one?

Tried using coax and while it looks like a great and makes for easy lead construction(That you can buy pre-made cables), I've found that it's typically annoyingly heavy and stiff.
Been using simple twin speaker or audio wire, picking based on feel and what I can get easily. Soldering to the BNC connector is annoying(You can get ones with terminals but they don't look as good) but the finished cable is light, portable and if I had my camera handy I'd take a photo.

I do also recommend spending the extra to find a switch with a nice positive 'click' when you push the button. It works fine with even touching wires together, but without the 'click' I've sometimes missed shots thinking I've hit the button but didn't or didn't realise I'd triggered it already.

29

Chronos User Discussion / Re: Accessories! (User designed ones)

« on: September 05, 2017, 05:51:51 PM »

I have no interest in producing these for anyone, before anyone asks. Your local hacker/makerspaces/fablabs will have them.. Plus I'm quite OK with krontech offering them, changing my design or even making whole new ones that are far better based on the idea.
Blaid_Strae, on krontech's download page is the 3d models. I went with clear acrylic as I like the look(I didn't include some structures just so you can see the text on the camera's front:) and that was the machine I had better access to at the time, however a 3d printed cover based on the same idea that has a baffle down the center, cone shape that fits over the lens mount and is better designed that how I've done it and fits the camera's curves perfectly would be a less pretty but far superior design.

30

Chronos User Discussion / Re: SD card size?

« on: September 05, 2017, 12:16:55 AM »

The biggest size file I've made sofar, using the full 4s buffer of my camera and one of the high framerates is about 300Mb.
But normally you mark in/out just the event you care about ad get a few seconds, or fraction of a second realtime. It also takes ages to write the full buffer.
So typically files end up 30-130Mb.