Messages

151

Chronos User Discussion / Re: Triggered Exposure Mode

« on: October 08, 2017, 04:48:17 PM »

Hi Doug,

In triggered exposure mode, the frame rate display does not show the actual frame rate, only the maximum you can run it at. You can't run triggered exposure faster than the camera is set to, it will drop frames.

The exposure control will control the shutter speed, provided you are triggering the camera at or below the frame rate it's set to. If you for example set the camera to 30fps and provide a 1000Hz trigger signal, undefined operation may occur. Let me know if you still have the problem with the shutter control when operating within limits.

Sound is not supported yet.

David

152

General high-speed discussion / Re: Multiple Cameras synced together

« on: October 07, 2017, 10:54:46 AM »

Set the master to frame sync output in trigger settings, and the slave cameras to shutter gating mode. Then connect all the cameras BNC ports together The master will then control the frame rate and shutter speed of the slaves, and they will be synchronized.

Edit: The slave cameras must be set to the same or smaller resolution, and the same or greater frame rate than the master camera.

David

153

Chronos User Discussion / Re: F-stop when using lenses from 35 mm camera

« on: October 07, 2017, 12:27:51 AM »

Hi - crop factor affects both focal length and f-stop - so f/4 on a 35 mm sensor will look like f/16 on the Chronos' sensor.

Unfortunately that's not correct. F-stop does not change with crop factor. f/4 on a 35mm sensor is the same as f/4 on the Chronos sensor. The only way the f stop will change is if you are using a speed booster.

Effective focal length will change, for example Chronos is about a 4:1 crop factor from 35mm, so a 28mm lens on Chronos would be like a 112mm lens on 35mm.

154

Chronos User Discussion / Re: C moutn adapotor

« on: October 06, 2017, 12:04:11 PM »

Hi Scott,

Check if your adapter has a facility to rotate the C mount relative to the B4 mount, sometimes you need to loosen a few screws to do this. If it doesn't support that, you can install the adapter on the camera, then loosen the set screw on the bottom of the camera using the included allen key. This lets you rotate the entire mount ring and lens/adapter assembly relative to the camera body. You can then re-tighten the set screw with the lens oriented correctly. Not that this will effect backfocus, you'll need to check your backfocus after doing this, and potentially rotate the lens by full turns to get the backfocus set properly.

As far as I know there is no standard orientation for a C mount, the lens will end up at an arbitrary rotational position when installed. Some lenses such as the Computar 12.5-75mm can be rotated relative to the mount to correct this, by loosening a black ring near the lens mount.

David

155

Chronos User Discussion / Re: Focusing Troubles

« on: October 03, 2017, 06:23:31 PM »

What settings are you typically using for aperture when you're having focusing problems?

Sometimes I find it helps to leave the aperture wide while focusing then close it down after, the increased reduced depth of field makes it easier to find focus.

156

Chronos User Discussion / Re: Streaming capacity

« on: October 03, 2017, 12:17:49 AM »

Hi Roger,

The h264 encoder is currently limited to 60fps due to driver issues. It's in the pipeline to try to speed it up, it should be capable of about 120fps at 720p based on pixel rate.

David

157

Chronos User Discussion / Re: 12 Volt power adapter.

« on: September 24, 2017, 09:00:18 PM »

I've used this laptop power bank with with Chronos, and it works perfectly. This one runs the camera for about 6 hours, and includes the proper plug adapter.

http://www.ebay.com/itm/Durable-30000mAh-Laptop-Battery-Charger-Dual-USB-Power-Bank-Pack-For-Cell-Phone-/152220326205

158

Chronos User Discussion / Re: What will the HDMI output resolution be?

« on: September 23, 2017, 11:07:44 PM »

1280x1024, with smaller resolutions scaled up to that resolution, and an option for 720p. Possibly also a clone of the on-camera screen at 800x480.

The 5V output should be good to 50mA as per HDMI spec.

159

Chronos User Discussion / Re: Trigger by application

« on: September 22, 2017, 06:17:27 PM »

Hi Eric,

The API required to do that is still being developed. Right now you need to control the camera using the onboard touchscreen.

It's probably about 2 months out till we have the API ready, but you'll be able to either save compressed files to some device such as a network share and then play them, or you can stream live video or playback video off the camera via RTSP to a video player.

Is there some preferred method you have for doing this? It would be good to have input on what people want to do and how they want to do it.

Regards,
David

160

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

« on: September 20, 2017, 09:55:44 PM »

They said they made several extra cameras to go beyond the current orders. So your wait should be just at the end of the existing orders in front of ya.

My deliver date is tomorrow.. cant wait..

Guess I need to finally decide on a sd now..

Well I have my SD card already here, just have to have some fast stuff to film so get some practice. Cat drinking water, Cat + laser pointer, hit-n-miss engine, gun stuff.

I'll also need to get some clarification on the "Do not expose the camera to molten metal". I presume they are talking physical contact and not simply close proximity.

"Do not expose to molten metal" refers to getting molten metal on or in the camera. Added this to the manual after a certain user broke their camera by getting molten metal inside after they built a liquid Pewter squirtgun.

161

General high-speed discussion / Re: Measuring Speed

« on: September 18, 2017, 07:24:44 PM »

I've been calling those things a "Scale" or "Scale sheet". For small ones, you can just print something out on a printer, calibrated to whatever your favorite unit is, 1cm wide lines work well for something that fits on a normal printer. It's really easy to draw out the scale lines in Paint or a similar program, then you need to figure out the print scaling, this usually requires a few test prints and measuring the size that actually came out.

For bigger ones, the best option is to mark out and mask off a piece of wood with masking tape, and paint the stripes on.

162

Chronos User Discussion / Re: Let's talk lighting

« on: September 15, 2017, 02:00:15 PM »

As a rough estimate, for a color camera, you'll need about 7 lux per fps at f/2 and 360 degree shutter.

So at 4000fps, you'd need about 4000fps * 7 = 28,000 lux. If you want to run f/4, you'll need 4x as much light, so 110,000 lux which is about noon day sunlight

I'm afraid you'll need far more light than those Manfrotto lights will provide, unless you're putting them right next to the subject. At 1m (3') distance you'd need 18 of those lights for f/2 4000fps

163

Chronos User Discussion / Re: Focus Aid

« on: September 14, 2017, 09:45:59 PM »

The zoom function was in the very early prototype cameras, and was switched out for focus peaking. An option for zoom will be back in the next update.

164

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

« on: September 14, 2017, 09:42:17 PM »

Did you press enter after setting your frame rate?

You need to enter the desired frame rate, press enter, close the keyboard, then press OK.

165

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

« on: September 13, 2017, 11:44:18 PM »

So far we've shipped 118 Kickstarter rewards and 67 of 157 store/PO orders, for a total of 185 cameras shipped out of 275 orders. 90 cameras remain to be shipped.

We're doing about 20-30 per day, so expect mid next week for getting everything out.