Frames and AVI's

[IanL]

How many frames would you normally capture in your AVI's or do you just keep going up till you get what you are looking for in the avi and then spice it.

Ian

[[1ponders] (Paul)]

Depends on what you are imaging, the camera you are using (colour/mono with filters) frame rate available, seeing conditions.

What are you using and what are you imaging?

[Dennis]

Hi Ian

Let’s use Jupiter as an example, with the AVI being processed in Registax.

To avoid any surface feature blurring due to the rapid rotation of Jupiter (approx 10hrs Jovian "day"), the rule of thumb is to capture for no more than 90 seconds.

Next, when we go to process the AVI in Registax, I have noticed that I need to keep the file size to below 1 gigabyte and the number of frames in the AVI to less than 9999 I think.

The largest frame qty AVI I have processed was 3000 frames at 910,000 bytes and everything held together.

Cheers

Dennis

[ballaratdragons (Ken)]

I don't do very much Avi work. I do long Exposures, but for todays Sunspots Avi's I captured 2000 frames for each pic. Dunno why, or what the standard is, but it felt about right when I was doing it.

[IanL]

Good point Paul, Jupiter and Saturn using the Toucam 840.

Thanks Dennis, I was thinking about 50mb and about 400 to 500 this is what i have been doing over the past couple of weeks. I think i crank it up a bit and see how it goes. I was out tonight but the seeing was terrible.

Ian

[[1ponders] (Paul)]

Saturn you can go as long as you like as long as you keep it under 1gig as Registax won't like it over that. Also try to avoid frame rates faster than 10 fps as you will get too much compression of the frames. The better your seeing the slower your frame rate and the shorter your exposure.

Using an 8" meade SCT with a 2X barlow and a ToUcam I had to set quite a high gain and 1/25 sec exposure for Saturn and not so high for Jupiter. Set your gain to keep the histogram at around 200 (for Saturn and a bit higher ^220 for Jupiter. You will see when it is too high Jupiter will start to burn out at the equator). With Jupiter the smaller your image (less magnification) the longer you can record, but Dennis is correct, with an appreciable image size then 90 - 120 sec is usually accepted as the maximum exposure time before you start to get smearing from rotational effects. So with a ToUcam set at 1/25 sec exposure and 10 fps you should be able to snag between 900 and 1200 frames.

BTW the lower the gain the less the grain. There is a trade off though in that if the grain is too low you might start to experience "Onion Rings". You will know what they are when you experience them

[IanL]

Thanks for that Paul. Onion rings don't like the sound that. Roll on better seeing conditions.