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A few questions on observing the sun


beamer3.6m

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I thought I may give solar observing a go with the Bresser Skylux 70mm. Not the greatest scope in the world but it shoudl do the job.

My questions are these:

1. What is the best way to filter this scope.

2. What would you use to image - webcam or DSLR

3. What magnification do you need to get the whole sun in an image

Cheers guys

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Having gained a recent practical introduction to the subject...

1: I think I'd go for a bit ot DIY and cheap / effective "solar film" of some kind.

2: Again, I'm "limbering up" with the cheapest possible Webcam (May afford a DSLR later)

3: Mostly down to (the dreaded) [a]rithmetic?

Visually, you just need a magnification that can accommodate the whole of the solar (or lunar <hint>) disk?

On [3], more specifically, the solar disk is ~0.5 deg across so, at prime focus of MY 500mm Startravel ST102, the resultant solar image is (approx) 500 x TAN(0.5) = 4.36mm! (by calculator). The most immediate problem is that the chip on SOME (many) webcams ain't big enough to accommodate this! I have had some success, using an ATIK 0.5x focal reducer and I'm moving (if it ever arrives) to the "Orion Starshoot Solar System Color Imager". With a 1/2" diagonal chip. :(

FWIW, I have had SOME success with solar imaging. I found a "Fringe Filter" helped, with a basic Achromat - against the "Purple Haze". I even found I could (to some extent) "Stack" Alt-Azimuth webcam "movies", as the Sun drifted across field. I KNOW I'm never going to excell at this, with a setup like mine, but it's quite fun, anyway? Have explored a bit of Eyepiece projection too. Again, the dreaded calculations... PLUS added uncertainty of image scale too! But, quite a fun to TRY to understand? :angry:

My limitation is, as ever, (my absence of) observing site. I STILL think I can do a bit of "White light Solar" and Lunar work. And, for closeups, maybe with my MAK127 and my "posh" Thousand Oaks Glass solar Filter. I sense this is (yet another) way to spend money though... :mrgreen:

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I'd use an old cheap eyepiece and use that to project image onto a white card, then photo image off the card, i'd also mask some of the objective to stop possible overheating and block off the finder just in case.

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Hi I use the Baader solar film on my ST120.

I use my 9mm orthoscopic frames the Sun nicely.

I do take afocal pics using a compact camera and generally these can show nice detail of sunspots.

Cheers

Ian

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