Which webcam?

[sologuitarist61]

This isn't a side to imaging I had considered really as I have been using a DSLR, but am coming around to the idea for solar imaging (mainly to save weight on my focuser which groans unders the strain!!). What cameras are best for this sort of work (lunar as well) bearing in mind that the prices of Philips cameras has gone through the roof lately. Also be pleased if you could tell me what software you use for your choice of camera to give me some idea as to what combinations work and what doesn't. Also I note that most images through a webcam seem to be extreme 'close-ups', is there any way around that - full image sun for example?

Thanks very much

[pete_l]

For bright targets such as the Sun and the Moon you don't need the low-noise characteristics of a (cooled) CCD. A standard CMOS sensor will do the job.

The problem with webcams is the tiny little (i.e. cheap) sensors they have. Slap one of those on the back of your 'scope and you'll only get a small fraction of the full image-circle. If you want a full disk (about 0.5° FoV) with a webcam, you'll need quite a short focal length. Something like 60mm F/L for a small webcam chip.

[sologuitarist61]

For bright targets such as the Sun and the Moon you don't need the low-noise characteristics of a (cooled) CCD. A standard CMOS sensor will do the job.

The problem with webcams is the tiny little (i.e. cheap) sensors they have. Slap one of those on the back of your 'scope and you'll only get a small fraction of the full image-circle. If you want a full disk (about 0.5° FoV) with a webcam, you'll need quite a short focal length. Something like 60mm F/L for a small webcam chip.

Thanks for that Pete, perhaps staying wit a DSLR would be a good thing.

[JamesF]

I guess with a webcam you could create a mosaic image of the Moon. The Sun might perhaps be more tricky though. As they're both fairly bright objects then a suitably-modded Lifecam Studio might reduce the total number of panels required as it has a fairly large sensor for a webcam. Not sure how well you'd do with control of colour on the moon and the ST120 though. I get a fair bit of CA visually with mine.

James

[sologuitarist61]

I guess with a webcam you could create a mosaic image of the Moon. The Sun might perhaps be more tricky though. As they're both fairly bright objects then a suitably-modded Lifecam Studio might reduce the total number of panels required as it has a fairly large sensor for a webcam. Not sure how well you'd do with control of colour on the moon and the ST120 though. I get a fair bit of CA visually with mine.

James

I have seen from your other posts re web cams and that you have mentioned the Lifecam before James. It would seem that you favour it for bright images but not planetary, is that right? What software do you use with it?

[JamesF]

I have seen from your other posts re web cams and that you have mentioned the Lifecam before James. It would seem that you favour it for bright images but not planetary, is that right? What software do you use with it?

My feeling is that it needs plenty of light because the pixels are small (almost a quarter of the area of the SPC) and it doesn't seem to be as sensitive in the first place. If you're imaging with, say, 300mm of aperture or more then you may well be able to put enough light on the sensor for it to work well. A small scope just doesn't have the same light-gathering capacity and my experience was that I ended up with a very poor quality image. I think the lack of light may also cause the firmware's white balance system to get itself in a bit of a mess, too. Where the Moon and Sun are concerned however, there should be more than enough light to go around.

I have the Lifecam Cinema rather than the Studio, but I think the same applies to both. If the clouds ever see fit to give me the opportunity to see the sun again in this lifetime then I'll certainly give it a try.

James

[sologuitarist61]

Thanks for that James, that is interesting. I too am down on aperture so it might well be worth looking into and aperture isn't so important for solar anyway, however, thanks for the tip.