File Size using TouCam

[shaneaust]

I'm using a Dell Inspiron 3200 laptop in conjunction with my 10" Dob to get some vids of various planetary objects. The laptop is running Win 98 as it doesnt have the necessary RAM to run XP (hardware limitation rather than simply not enough RAM). I'm also utilising a TouCam Pro 840k to do the image capturing, via .avi files.

When I use TouCam on this PC, I usually take a 10 second shot, at 25 fps. Not a lot of frames involved, right? So you'd expect a small-ish file size, right?

What I usually end up with is a file size of ~ 35 meg, for an avi file! :eyepop:

I transfer this file over to my desktop PC which runs XP and is reasonably powerful. I have a file conversion app that I use to "convert" that .avi file into yet another .avi file - resultant file size is then ~ 3 meg max.

Anyone know why the original .avi file is so large?? Is it because of the hardware involved (slower laptop) or the fact that W98 is being run?

Its not a major hassle, but my HDD on the laptop is only 5 gig or something and I worry that one night I will have a spectacular opportunity to get some good shots, only to find out that I've been recording too long and have run out of storage space.

TIA.

Mick

[ballaratdragons]

Hi Mick,

sorry, but I don't understand about pooters, but I do know that a toucam is a hungry beast. I run my toucam in 2 different old, small lappies and both handle it well but they both have XP on them.

Try running the toucam through a USB2 card. It helps.

[shaneaust]

Thanks Ken - I did try that but it didnt make any difference to file size. :shrug:

[ballaratdragons]

Mick, this is what I usually run my Toucam at: 58.14Mbps @ 640 x 480 pixels.

Most of my Avi's are about 10 - 15 seconds long.

10 seconds x 58.14Mbps = 581.4Mb

[[1ponders]]

Hi Shane.

The way I understand it is the the avi only acts as a method of stitching individual bmps together and at 640x480 each bmp is 901kb.

There are three things you might want to consider.
1. don't compress your avi. Leave it at the larger size then run it through Registax. You will get better adjustment with your final image and achieve better results with the least compressed avi. 250 meg files are not uncommon for me. Even 500 meg happens now and then depending on what I am shooting.

2. Even though you will get less frames, think about capturing at around 15 fps. Any faster than this and your images start to suffer from compression. The standard is usually around 5- 10 fps.As a general rule, if the seeing will allow it the slower the better with a ToUcam. One thing you can do if you don't have tracking is to collect a series of avies and then join them together with Virtual Dub (free) or convert all your avies to bmps (again using Virtual Dub) and then run all the bmps together in one run through Registax. It is a lot of work though.

3. If you haven't already done so, have a read of Iceman's Astrophotography with a Dob (http://www.iceinspace.com.au/index.php?id=63,201,0,0,1,0). He has been through exactly what you are trying to do, planetary imaging with a non-tracking Dob. We are still wondering about his sanity :lol:

[shaneaust]

Ken: That is really interesting...how in the heck do you set the TouCam to acquire images at megabytes-per-second instead of frames-per-second?? I didn't think megs-per-secod was possible with that cam - I know on mine it's not poss....

Mick

[ballaratdragons]

I do capture at 'Frames per second'. I looked in Properties of my Avi's and it tells me that they are captured at 58.14Mbps.

I generally stay on 25 fps for Solar system, and 5 fps for deep space on Long Exposure.

I don't understand all the figures, I just looked in 'Properties' for you.

Are you capturing at 640 x 480 pixels?

[shaneaust]

Okay, that explains it - my avi properties on the laptop are about 900kbps..but when I use the converter, it converts at 224kbps.

Yep, I am capturing at 640 X 480.