Planetary Imaging with Omegon Camera in Firecapture - White balance?

[Tommohawk]

Hi all. Have been offline a while, sort of lost my Astro Mojo. But with Jupiter looking good thought I'd get set up again.

I got an Omegon 385MC couple of years back which works quite well but when I last used it I could only use Toupsky to capture. To be fair it's pretty good, but I now see that Firecapture can use Omegon cameras and thats what I always used to use in the past when doing mono.... so I'm trying to get set up with  that - some of the tools like image stabilisation when focusing are really useful.

Anyhow, I'm struggling with white balance and cant find a way to auto white balance or balance channels manually - does anyone know how? Toupsky had an auto white balance that works really well.

I've searched around, and I dont seem to have the WRed Wblue sliders that I've seen out there on the tutor type forums. TBH I neve really understood if the WB affects the recorded image or just the screen.

Anyone got any thoughts please?

[symmetal]

In  Firecapture's 'Control' section where you set the camera gain and exposure, click the button labelled 'More'. You'll see more camera options, and among them should be red and blue gain sliders. To get a reasonable colour balanced image on ASI cameras I usually have the red at around 45 and the blue at 95.

Firecapture doesn't have a white balance button, as for any object except the Moon or Venus, it would give the wrong colour result. Use the Moon to get an idea of where the Red/Blue sliders should be to get a grey colored Moon and those settings should be pretty good for the other planets. You can always make final colour adjustments later in your processing software anyway.

The red and blue gain settings will affect the recorded video.

Alan 

[Tommohawk]

Thanks for that Alan. Problem is I dont have those red and blue sliders even under "more" settings. I dont have another OSC camera to compare it with, but I'm guessing its something to do with Omegon SDK - not that I particularly understand what thats all about!

Is there no way of just manually tweaking the gain per channel under the histo settings?

[symmetal]

Pity those options aren't available with the driver as implemented by Firecapture.

The histogram just lets you see the results of changing the gain, exposure, offset etc., so histogram settings don't allow those parameters to be changed independantly as that would be confusing.

It's no great loss not being able to change the colour gain as that can easily be done in post processing anyway. I assume if the options aren't available in Firecapture they are stuck in the default 50% gain setting. If all three colours are showing on the histogram but the blue is around 25% that of the green and the red is like 80% of green then that looks about right.

Alan

 

[Tommohawk]

Thank Alan for all that - very helpful.

One of the issues I have with astrophotography  (and life in general!) is that my memory isnt so good these days. I find myself going over issues that I've either solved, or accepted that I can not solve, at some time in the past.

So, on Google searching these issues I now find a similar thread I posted some time back, and a response from your good self!!

That query had more to do with Bayer patters, but one conclusion I reached at that time is that for some reason FC can't deliver the frame rates that I get with Toupsky, and although FC has been updated, it still doesnt give fast rates - maybe because there is no USB traffic option for the Omegon camera. Heap size and buffer settings look good, and tweaks make no difference.

TBH I've always found frame rates on FC slightly variable, even with my conventional ZWO cameras. Touspsky seems to perfomr much more consistently re FPS. Cant think why as FC is obviously very sophisticated. I wondered if Toupsky was somehow cheating by compressing the files or something, but I dont think so - file sizes all look sensible.

I can live with the lack of on screen WB, and just fix in processing - just got to be careful not to clip any channel. So if only I could get the frame rates up with FC that would be great. Not sure if you have any thoughts on that? Maybe mention to FC dev, Torsten I think?

[symmetal]

Hi Tom,

I remember my previous posts to you concerning bayer patterns. 🙂

With regard to improving frame rates, these are good settings to use.

I assume you've got a ROI just covering the planet to avoid downloading unnecessary background sky data.

Use 8 bit capture and not 16 bit. Stacking will give you extra bit resolution up to around 12 bits anyway if captured in 8 bit.

Use an exposure of 3 to 5mS if possible to freeze the seeing. 5mS will theoretically allow 200fps though other factors will limit this. At 20mS exposure you will never get above 50fps.

Use a high camera gain setting to enable you to reach those shorter exposures, and still have a histogram peaking around say 75% It will look horribly noisy on the preview but stacking will remove pretty much all this extra gain noise.

Two other options which help but you may not have in camera 'More' settings are USB Traffic which can usually be set to 100% on planetary ROIs without causing corrupt or missing frame videos. The other is 'High Speed Mode' which reduces the camera A to D convertion bit resolution by 3 or 4 bits and so allows quicker data conversions. As you're capturing in 8 bit anyway which will still be lower than the High Speed Mode resolution this won't matter.

If these options aren't available a message to the FC developer may well help so good luck.

Finally an SSD is highly recommended for storage. FC allocates memory to a buffer for storing video frames and indicates the buffer size remaining while capturing the video. If this reaches zero your fps rate will drop considerably. Depending on your ROI size and heap memory allocated (used for the buffer) it can run out of buffer in just 15 secs or so. While recording, FC is also writing this frame buffer to disk so freeing that buffer space back up. A normal mechanical hard disk can't write fast enough and so the memory can't be freed up quickly enough to avoid it eventually running out. An SSD can write about as fast as the data is received so your buffer size remaining may not show any drop at all or drop slowly enough that 5 minute captures are easily done without it reaching zero.

Hope these help. 🙂

Alan

[Tommohawk]

Thanks again for that Alan.

I used to do quite a bit of planetary imaging with mono so am familiar with most of the setting options that you mention - always good to be reminded though! I'm using 8 bit, SSD, USB3, buffer and heap settings as normal.  Its just this Omegon camera which is giving me grief with frame rates BUT only with FC.

At 5ms exp full frame on Toupsky I get 120 fps as advertised, and 197 fps for 640x480 ROI.  On FC full frame is a very flakey 60fps, and 640x 480 ROI is 136.  

I'll try messaging Torsten and see if he has any thoughts. 

TBH my main issue here is trying to evaluate the camera - it doesnt seem to quite perform as well I would expect, and I'm not sure whether its something to do with Toupsky - so would be good if FC was working optimally. 

 

Edited October 10, 2023 by Tommohawk

[symmetal]

I checked the manual for the 385C and it's a 12 bit camera but I couldn't see any mention of a 'high speed' mode. On ASI 12 bit cameras this turns it into a 9 bit camera and it does significantly increase your fps.

However I did find this statement in the Omegon manual

Quote

Imaging through the ASCOM Platform is only recommended for deep-sky astrophotography. High framerates (recommended for solar-system astrophotography) are usually not possible via ASCOM. Windows DirectShow driver allow high framerate video capture when using the Omegon Pro cameras with third party software (e.g SharpCap). As a downside, the DirectShow interface doesn’t allow full control of all camera parameters.

In FC you're using the Ascom or DirectShow driver, so will have the issues quoted which may explain your problem. If you're using DirectShow this may explain why you have no colour gain controls. If you use the Ascom driver do they appear?

This FC webpage states that DirectShow drivers may not work properly with some cameras. DirectShow is a webcam driver so likely wouldn't have astro related features available. The Ascom driver not allowing high framerates is an issue with Omegon or Toupsky not having implemented a full Ascom driver and not a FC issue. Zwo cameras work fine at high fps via Ascom.

Alan

Edited October 11, 2023 by symmetal
Incorrect information crossed out

[Tommohawk]

Thanks again for taking the time to find those details. I couldn't find any options to choose drivers? Can you point me to where that option is in FC? Or maybe it's in Windows device settings?

I'm out at the moment so can't check anything. To restate, Toupsky does provide the expected high frame rate. It's only on FC that it's slow. My Zwo cameras work fine on FC. 

[symmetal]

Hi Tom,

I got it a bit wrong on my last post. Firecapture uses the native drivers when you select the camera manufacturer from the FC startup page (visible when no camera is connected). If it recognizes the camera, which means you've already selected the Omegon camera previously and the native driver is already installed, it skips the camera select page and uses the Omegon native driver.  You can choose to use Ascom on this startup instead of the native driver. Not sure how DirectShow drivers can be used as there's no option to select them in FC anyway as far as I can see.

So you should be using the native driver anyway in FC, the same as your Toupsky program uses. If you have options in the Toupsky program like individual colour gains, high speed capture and USB Traffic which aren't visible in FC, it's worth contacting Torsten.

It seems Ascom drivers don't have the options for high frame rates so any camera using Ascom drivers wouldn't work so well in FC either, including ASI ones.

Alan