1 modded Lifecam HD + No Idea = Mars as a Star

[nictori]

Well, I finally found a spare eye piece and proceeded to mod my expensive HD cam ($40...gotta love it ). Mod went well so off I went outside and figured it didn't matter what the seeing was like....my huge 3" scope was gonna take a blumming photo or die in the attempt.

Happy to say that the cam worked well....really realised that a barlow would be great.....and found that Mars is really a star...no really...it is.....couldn't be the lack of skills I have...hee hee...

Anyway....not the best pic of Mars but I'm happy the thing actually worked. Now just have to upskill myself from completely inept to slightly useless...

Only way is up from here....

Mars 1st Attempt 23 Apr 2012 9-17pm.bmp

[samtheeagle]

Looks like you need to drop the exposure time down a load The camera is soaking up too much light and is saturating, hence the star-a-like picture. There's plenty of info on the forums here, have a bit of a search and a browse around, you'll have it all figured out in now time!

[JamesF]

I think that star-like effect might well be initially due to a high gamma setting. If your gamma setting isn't zero, I'd wind that back as far as possible and then work from there with the gain. I tend to start from the camera defaults, zero the gamma setting, take the frame-rate down as low as I dare given the seeing (usually I work at about 10fps with my SPC900, but the Lifecam could go faster if the seeing is poor), get the longest exposure I can given the frame rate and then set the gain at the point where there's enough brightness that the image is reasonably clear. Ideally you want as little gain as possible, but you need enough that in processing it can be distinguished from noise. I can't really tell you what's wrong or right there I'm afraid. Experience is really the best tutor there.

Mars is shrinking rapidly, as it were. As we travel away from opposition, it's taking on a gibbous phase and becoming a rather more tricky target, so it will probably take a bit of practice. It hadn't occurred to me that the change would be so pronounced, so I'll be trying to image it whenever I get the opportunity over the next few months just to watch its progress. To demonstrate what I mean, these four images were taken on the 17th March:

and this on 21st April:

I had to raise the gain setting significantly for the later image because of the reduced light levels. Interestingly, the polar icecap already appears to be growing again. Part of me wants to believe it's an optical delusion. It seems amazing that we'd be able to see the change in size of the ice over such a short period.

Haven't managed to try my modded Lifecam Cinema out yet. I'm still layering the paint over the LED to try to block it out. It's exceptionally bright. I'm half-tempted to cut a tiny square of insulation tape to fit over it and "glue" it on with a bit more paint.

James

[samtheeagle]

Excellent example of how quickly the apparent size can change

When I nerfed the LED on my lifecam I just used a good size blob of black acrylic paint, job done. What sort of paint are you using?

[JamesF]

I'm using some smooth hammerite because I happened to have it lying about. I've done three coats, but whilst it's much reduced in brightness it's still clearly visible and will generate reflections inside the camera housing. My son might have some acrylic paint somwhere. I'll see if I can find it and daub a blob of that on it next.

James

[samtheeagle]

I didn't apply coats, I dropped a bomb

100% effective, not a jot of light getting out of there now.

[JamesF]

Perhaps I just need to be brave and apply a larger dollop of paint.

James

[JamesF]

I have just done so. I shall test it once the paint dries. Now who said that wasn't exciting, eh?

James

[samtheeagle]

[rjsc2001]

Hi

Can you tell what setup you used to take this wonderful pictures? Was it with the 3" scope?

And you did stack them, didn't you? how ? with what program?

thanks

Ricardo

I think that star-like effect might well be initially due to a high gamma setting. If your gamma setting isn't zero, I'd wind that back as far as possible and then work from there with the gain. I tend to start from the camera defaults, zero the gamma setting, take the frame-rate down as low as I dare given the seeing (usually I work at about 10fps with my SPC900, but the Lifecam could go faster if the seeing is poor), get the longest exposure I can given the frame rate and then set the gain at the point where there's enough brightness that the image is reasonably clear. Ideally you want as little gain as possible, but you need enough that in processing it can be distinguished from noise. I can't really tell you what's wrong or right there I'm afraid. Experience is really the best tutor there.

Mars is shrinking rapidly, as it were. As we travel away from opposition, it's taking on a gibbous phase and becoming a rather more tricky target, so it will probably take a bit of practice. It hadn't occurred to me that the change would be so pronounced, so I'll be trying to image it whenever I get the opportunity over the next few months just to watch its progress. To demonstrate what I mean, these four images were taken on the 17th March:

and this on 21st April:

I had to raise the gain setting significantly for the later image because of the reduced light levels. Interestingly, the polar icecap already appears to be growing again. Part of me wants to believe it's an optical delusion. It seems amazing that we'd be able to see the change in size of the ice over such a short period.

Haven't managed to try my modded Lifecam Cinema out yet. I'm still layering the paint over the LED to try to block it out. It's exceptionally bright. I'm half-tempted to cut a tiny square of insulation tape to fit over it and "glue" it on with a bit more paint.

James

[JamesF]

Hi

Can you tell what setup you used to take this wonderful pictures? Was it with the 3" scope?

And you did stack them, didn't you? how ? with what program?

You're confusing your attributions. I'm not the one with the 3" scope. I took these with a 127 Mak, Revelation 2.5x barlow, exension tube and SPC900. Stacked 2700 frames out of 5400 in Registax.

James

[rjsc2001]

Oh, ok

sorry for the confusion

[Delboy_Hog]

James, cracking pictures! I've seen a few people on here with the 127 + barlow + extension + SPC900 combo. Is it a set up you get on well with? The results certainly look impressive!

[JamesF]

Yes, I find the 127 Mak a great scope to own. And whilst it's taken a fair bit of time to get the hang of planetary imaging (not to mention completely stripping the scope and rebuilding it, and motorising the focuser) I enjoy imaging with it. Whilst not wishing to blow my own trumpet too loudly, I think that set of four Mars images is perhaps as good as it's possible to get with the setup I'm using under UK skies.

I find the 2.5x barlow plus extension gives me somewhere between 3x and 4x normal image scale, but if I step up to a 4x ImageMate I really struggle to overcome the mirror shift when the focuser changes direction -- it's enough to take the right across the camera sensor and more at that point. I think that's probably a weakness of the design and the only way to overcome it would be to fit an external focuser. That does seem overkill considering that a decent focuser would probably cost more than the OTA and that I'd personally be better off getting my permanent setup sorted so I can start using my C9.25 again

(To be fair to the scope I should point out that I bought it second hand and I'm not even sure the person I bought it from was the original owner. It has always shown signs of plenty of use. A brand new one may not suffer the same problems as mine, or perhaps not to the same degree.)

James