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Everything posted by Jessun

  1. Jessun

    Dedicated DSO camera confusion!!!!

    Hi, I would start with this site: http://www.newastro.com/book_new/camera_app.html Download the CCD Calculator. It's similar to the one in the advice above, but personally I like this better. Three quick questions to answer: - What is the resolution that is useful at your location? Measured in arcsec/pixel, this is determined by the quality of your sky. In this context it has nothing to do with the number of pixels on a given CCD, it's just a figure that applies to your location and perhaps your ambition. At this stage you will need to match the pixel size of a CCD you consider with a certain focal length to achieve this ballpark number. - What area do you wish to cover in one frame? Narrow for planets or large for nebulas? The actual CCD size determines this. Costs typically go up as they increase in size. - How fast would you like to expose? Having found the resolution you'd be happy with and the focal length of a scope matching this, it's time to look at f-ratio, in other words as you maintain the focal length you open up the aperture of the imaginary scope. Each inch adds a lot of money. As to cooling, it's not as simple as cooler is better. It depends on how one particular CCD handles heat. Some CCDs are more forgiving than others and manufacturers match the cooling needed to the CCD. They can only cool a certain number of degrees below ambient temperature so your location might be a factor. In a hot country with warm nights it's worth looking at cooling specs. Astrophotography is complicated and most rigs you'll see are slightly different to suit the user - or the user's budget. Part of the hobby is to learn enough to find your perfect rig, and this is time consuming. I have spend days looking at the CCD calculator alone... Good luck! /Jessun
  2. Jessun

    Mount Stops Slewing

    Shot in the dark: does the handset have a battery? /Jesper
  3. Looks superb and very innovative to me! /Jesper
  4. Jessun

    The future for mounts?

    Amazing how such wobbly and thin looking cogs can be so strong. Always wondered what an industrial robot would be capable of carrying a scope. It would be quite a sight. /Jesper
  5. Interesting thread. Did anyone run a CMOS with at least 5 or 10 min subs? Would amp glow or something else destroy the image? /Jesper
  6. Hi! I have looked through a telescope only a handful of times, using the dark hours exclusively to image. The scope back then was a SW120ED and the eyepieces cheap ones. Now I'm breaking up my imaging rig which leaves me with one or two APM LSOZ 105/650 to use for visual work. The questions that pop up are: - Is there a great difference looking through one scope vs looking through some kind of bino setup? - For the scopes above, what eyepiece could you recommend for Moon and which one for DSOs? I have no budget for a nice collection... I literally know nothing in this field of the hobby. /Jesper PS Perhaps better suited in the 'Getting started with observing'. Total newbie here...
  7. Question from a CCD guy, why are CMOS files larger? Not just the added pixels? /Jesper
  8. Jessun

    M31 (Esprit 150 core + ED 80)

    Absolutely stunning! Great colours! /Jesper
  9. Hm, 21.8 + about 15 = 36.8. About 18mm left. Might be some other OAG out there that you can squeeze in? With the stuff I use, M68 rotator and the Riccardi M63 reducer I'd be at about 74.5mm. 75.6 is recommended so I still have room for a stamp! OAG? Nope... but never used one. /Jesper
  10. Got a reply from Vince as well. The square threaded plate around the CCD window of the 16200 comes off and the EFW3 bolts on from inside the wheel housing. (I'd be willing to guess that one might drill holes in the EFW2 as well for this purpose). The back focus saving is about 5mm. Great stuff!! /Jesper
  11. I'm thinking about stepping up the filter size, but I'm at loss regarding the many different sizes around the 2" mark... The new Atik EFW3 comes with wheels in either 2" or 50.8mm according to FLO. To me that's pretty much the same dimension. Astrodon sell 50mm unmounted, so what version of this FW would I need? /Jesper
  12. Jessun

    50.8mm, 50mm, 2" filters???

    Yes, odd mistake to do. In any case the Astrodon filters are listed as 50mm. /Jesper
  13. There were still some odd lines in there, and what looked like rotation. (as if the software tried to align the flat - well flats don't move...) /Jesper
  14. You can always add a fuse if you want to. I cut all my cig plugs and went for banana plugs or XLR plugs. /Jesper
  15. Jessun

    50.8mm, 50mm, 2" filters???

    Yes indeed! I'm confused by the options here. Giving it another thought I realize that 2" is 50.08mm and not 50.8mm but that hasn't solved the mystery. All I ever used was 1" or 2" mounted filters. Gives me something to hold on to as I handle them... /Jesper
  16. Very odd indeed! The flat looks inversed and way to blotchy without showing a single dust bunny on any optical surface, and I don't get the sharp lines in the stack either... The luminance with no flat looks amazingly flat as it is. I have no idea what's going on here! /Jesper
  17. But just to be sure, I'm asking a question here, and I don't know how these units might fit together. /Jesper
  18. For rotation I have for years relied on these: https://www.teleskop-express.de/shop/product_info.php/info/p6983_Baader-M68-Zeiss-Gewinde-Schnellkupplung-und-360--Rotation.html But they build 25mm so I'm keen on not busting my available back focus. It worked a treat with the EFW2 and the Atik460 and I can't afford too many millimetres... /Jesper
  19. Attaching this to a 16200 it says that the front plate can be removed to shorten back focus. Do I understand this correctly that the square threaded piece, that's bolted with what looks like 6 screws onto the 16200, can be removed and that the EFW3 is then bolted straight to the camera body so it sits flush? What thickness is this piece? Or even better, what would be the total back focus using this method of attachment? Thankful for any input :-) /Jesper I see these small holes being perhaps the way to facilitate the bolt on?
  20. Jessun

    More supermoon hype...

    That in itself is rather a positive thing I'd say. No one in the target audience is calculating the resolution benefits for imaging... If it can get people interested in the grander scheme of things, just a tad past Instagram, I'm all for it. Personally, I detest that pesky orb at any size ;-) Ok, it was good for evolution, but now it can jog on... /Jesper
  21. I'd be inclined to agree with Alan on this one. Get something easy to use that has the goto and tour function. I wouldn't mind one myself :-) /Jesper My daughter at 2.5 years old was happy with just a simple bird watcher scope.
  22. Jessun

    Hi from south of France

    Welcome to SGL Anthony! It's a great source for knowledge and friends. Good little scope you have there too! /Jesper
  23. Jessun

    Astronomers and flight...

    Don't know what you're talking about ;-) My ol' friend:
  24. Jessun

    CLS-CCD EOS Filter

    Or balance the colours in software to combat the LP. I never used an LP filter and live in the centre of a large city. Jesper

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