Settings and Filter

[Stargazer Jack]

Hi, I am wondering what would be ideal settings for imaging the sun. I don't really need exact settings but more like how much gain and whether I should use a histogram to help me with brightness. Also, is it worth purchasing a Baader Continuum filter for my telescope to help me when I image the sun and has anyone done a comparison with no filter and with one. Thanks in advance

[JamesF]

Assuming you're using the SPC880 for a starting point I'd set the frame rate to 10 and adjust the exposure and gain to give you about 50% to 60% histogram fill.

James

[GreatAttractor]

Jack, Solar Continuum would be best used with a mono camera. I tried it with Lifecam HD-5000 (color) and effects weren't encouraging. I did a comparison of filters using PGR Chameleon mono here:

Note that Solar Continuum alone leaks infrared, so it needs a UV/IR cut filter.

[GreatAttractor]

Jack, Solar Continuum would be best used with a mono camera. I tried it with Lifecam HD-5000 (color) and effects weren't encouraging. I did a comparison of filters using PGR Chameleon mono here:

Note that Solar Continuum alone leaks infrared, so it needs a UV/IR cut filter.

[JamesF]

Note that Solar Continuum alone leaks infrared, so it needs a UV/IR cut filter.

Just to be sure I understand, are you saying that the solar continuum filter passes IR that is already present, or that it emits new IR that wasn't there to start with?

James

[Stargazer Jack]

James, thank you for that advice. Would you suggest changing the gain more or exposure to fill it up or shall I just do it equally?

[Stargazer Jack]

GreatAttractor, thanks for the help with that it is better on mono cameras. Your comparison is also very helpful

[Merlin66]

It appears that there's a resonance band in the filter which may allow some IR to get through. This is very weak and may not affect all CCD cameras....hence the comment re UV-IR for imaging....

[Merlin66]

< Double post> ?????????

Why is this so??

[JamesF]

There's a problem with double posts at the moment. Or, at least, with the post you've just made being displayed after hitting Post. So you do it again thinking the post has not been made and end up with a double post.

James

[JamesF]

James, thank you for that advice. Would you suggest changing the gain more or exposure to fill it up or shall I just do it equally?

You may need to experiment a bit with that one. I might be tempted to set the exposure time as fast as possible and adjust the gain accordingly and see how it turns out, then increase the exposure and lower the gain and retry, then again and so on. See what works best for your kit.

James

[Stargazer Jack]

Thank you James, one last question, is there a limit I show put on the AVI or should I just aim for around 3-5 minutes for each one?

[JamesF]

Again, probably worth experimenting with, doing some runs of 1,2,3 or more minutes and seeing how things turn out. Things can change reasonably quickly on the Sun, so I wouldn't go made and start doing ten minute runs or something like that though. It's a huge amount of data to stack, for a start.

James

[GreatAttractor]

Just to be sure I understand, are you saying that the solar continuum filter passes IR that is already present, or that it emits new IR that wasn't there to start with?

James

Passes the present. I was especially confused during my early attempts with achromat and a Lifecam - I had a completely overexposed and impossible to focus image, even with Solar Continuum. Bizibilder suggested an IR-cut filter and that did the trick.

[markt]

Yes, you must use a UV/IR cut filter with the Baader Continuum, it is hugely leaky above 700nm...