Firecapture settings

[Ozone]

Any recommended settings for Jupiter and Saturn? Ask 224mc, 6" mak

[symmetal]

Hi Ozone,

You want the exposure to be short to hopefully freeze the 'seeing' so on the 'Control' section set the camera parameters initially for an exposure of 10mS and unity gain of 135 for the ASI224, gamma off (unticked). Click the 'More' tab and adjust the brightness (camera offset) so that the left edge of the histogram is close to the left edge but not clipped. To get the colour looking about right you'll need to set the Blue gain to about 95 and the  Red gain to about 55. You can set the colour gain more accurately by looking at the Moon and adjusting them for a grey image (all three histogram colour bars the same length.) The rest of the 'More' options can be left as they are for the moment.

You now need to adjust the exposure and gain to get a bright but unclipped image, with the right hand edge of the histogram around 80% of max. If it's too bright reduce the exposure or reduce the gain. If your exposure is down around 2mS or so reduce the gain to alter the histogram. If it's too dark  you can increase the exposure which will reduce your max FPS and possibly make the image less sharp due to the 'seeing' bluring the image. Try increasing the gain to get a brighter image. You can use quite a high gain value where the preview looks very noisy but when stacked the noise is dramatically reduced. If you alter the gain a lot you may need to readjust the brightness setting.

On the 'Image' section select Max size to make finding the planet easier and then select a ROI so that the planet fills most of the frame. Leave it at 8 bit capture (don't tick the 16 bit option). If you have debayer icon ticked on the column to the left of the preview window so that you see a colour image you can't select 16 bit anyway. If you record enough frames (more than 50) the 4 bits lost by selecting 8 bit over 16 bit (12 bit really for ASI 224) are recovered anyway (as long as there is noise in the image, which there will be.) Select AVI or SER video format. SER is the preferred Astro format as it allows 16 bit recording and is recognized by most/all stacking programs. The free SER Player is a handy program to preview your SER files and show useful info.

Select the arrow to the right of the debayer icon and tick the option 'Temporarily disable debayer' so that you don't debayer while recording, just while previewing. Debayering takes processor time and reduces your FPS. Your stacking program will do the debayering for you.

On the 'Capture' section click the 'limit' button to select your video recording duration. Start with 30secs. You can go longer, 2 minutes or more to get more frames but need to be aware of Jupiter's fast rotation which can start blurring a long video when stacked. Saturn rotates more slowly so that isn't such an issue.

Under 'Status' check your actual FPS. The 'max' value is limited by your exposure setting. At 10mS max is 1/10mS =100 FPS. With a relatively small ROI you should be getting at least 50FPS, though it depends on your PC hardware speed.

Now click the Record button on the 'Capture' section. With a small ROI you hopefully won't run out of RAM before the end of the recording which will cause your FPS to drop right off. If you have an SSD disk installed to record on, the RAM won't be an issue as it can normally write the images to disk as fast as they are being read from the camera.

This should get you started. When you get more familiar you can play around with the settings to see if you can improve things a bit more. 

Alan

Edited July 27, 2019 by symmetal