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Jessun

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Everything posted by Jessun

  1. Jessun

    Is this the death knell for CCD cameras?

    Very interesting. I remember a colleague who bought a 40" Plasma for £10.000 back in the days. Early adopters will always pay the price. I'll stick with CCDs for a while longer, because I'm used to them and don't mind spending some more time on a target to make up for lower QE. It's interesting though how the rise of CMOS blows life in the age old argument about sub length - short vs long, which was often simply dealt with on a theoretical level. /Jesper
  2. Jessun

    Dual rig ccd cameras

    I ran three ED80s simply bolted down. It's easy to adjust one ring 'sideways' (Dec) to match the FOV of the other. Then I used tinfoil to make shimmy bits for 'up and down' (RA) if that makes sense. I got fairly close. I got some adjustable saddles from FLO but never got to try them out before breaking the rig down. May or may not be better. /Jesper
  3. Jessun

    Which scope for NB ?

    I'm with Olly on this. You certainly have a whole arsenal to experiment with. I think you'd be hard pressed to tell the difference. I used ED80s with some success at 1.8 arcsec/pixel. I print 6000*4800 after a PS enlargement and they look great. Well, to me at least. Aperture is great for max theoretical resolution if you have seeing and a camera to match, but f-ratio makes for quicker exposures of course. You're comparing 5.9 vs 7 native? Fairly similar, insofar as conditions on the night will have bigger influence. NB is great for big structures of course so I'd go for max FOV. (Which is what I'm working on myself at the expense of resolution) /Jesper
  4. Jessun

    OTA Alignment

    Can you rid focuser from the compression ring setup and start from scratch at that end? It's a 2.5" focuser? Ought to be threaded on the inside. /Jesper
  5. Jessun

    Remote musings

    I agree, what a kit! Good luck with the build! Got the Atik 16200 with EFW3. As you say, that's probably the easy bit to get running. Looking forward to the updates! /Jesper
  6. Hi SGL members! As I'm moving to 2" filters I wish to sell my 1.25" mounted filter setup. This setup consist of a kit of Baader LRGB as seen here for example: https://www.teleskop-express.de/shop/product_info.php/language/en/info/p563_Baader-LRGB-CCD-Filtersatz-1-25----Interferenzfilter---4-Filter.html @268 Euros plus the piece de resistance, the Astrodon 3nm ones; Ha, SII, OIII. New they are 608 Euros a pop.... Example: https://www.teleskop-express.de/shop/product_info.php/info/p5153_Astrodon-1-25--Narrowband-Filter-H-Alpha-3nm-mounted.html I will part with the LRGB set for £150 and the Astrodons for £450 each of £1200 for the lot of three. That is effectively most of the haggling done already. These filters rendered me six AAPODs in one year alone, and that was with mediocre OTAs and substandard processing skills... I can accept PayPal, UK or French, UK or European Bank transfer, I can ship from the UK or France, no problem as I tend to go back and fourth. Let's say £7.50 per filter shipping cost for insurance purposes. They will also be available for pickup in London shortly. The filters have never been cleaned or wiped. They have lived in Atik Filter wheels as long as I had them. Below: LRGB set to the left, Astrodons to the right. /Jesper PS There might be an ATIK EFW2 up for grabs too once these are gone ;-)
  7. Just curious here, where can these be bought at that price. I shopped from the vendor in the link. Perhaps that was a mistake.... /Jesper
  8. LRGB sold. NB still available.
  9. Jessun

    Whale Galaxy, two scopes.

    Silly good! /Jesper
  10. Jessun

    When to use use light pollution filters?

    I always imaged form a city and never used LP filters. The resulting effect is a sickly orange that you can remove easily by simply balancing the colours in processing. A great deal of the LP comes from reflection of vapour and particles and you'll have to learn to fight these effects regardless of the use of LP filter. /Jesper
  11. I just looked at the prices as linked above. Was not aware they could be had cheaper. Ha purchase date: 05.08.2013 OIII and SII: 17.09.2013 LRGB: 28.08.2013 Cheers!
  12. Tricky one, since guiding traditionally relied on a human turning little wheels to keep a star in the cross hairs. These days with various software calculating centroids to a fraction of a pixel it's perhaps a different story. Any too precise theoretical calculations might perhaps tempt you to chase the seeing rather than stay put and guide on an average position - which is something that software can do for you over a vast range of scope 'ratios'.
  13. I've used little Shuttles for some time and as I'm downsizing my rig I'm experimenting with bolting one up by the OTA. The big fail vs. your wish list is the 12V. My particular ones run off 19V... Something I overlooked at the time of purchase to be honest. Apart from that this it's another route perhaps. My one runs a Celeron 1037U dual processor at 1.8GHz. A decent amount of RAM and an SSD helps with performance. I run TheSkyX Professional and other bits and bobs in this with ease. /Jesper
  14. Go with these ones instead: https://www.teleskop-express.de/shop/product_info.php/language/en/info/p6044_Baader-Astro-Physics-CDP-Gegengewicht-6-kg---rostfreier-Stahl---28-5mm.html They do 3kg versions as well. Superb quality. Personally I'd be diligent with matching bar and centre hole. Welcome to SGL as well! /Jesper
  15. Jessun

    Dual ED80 setup

    That Geoptic bar looks familiar ;-) I used three to run three OTAs bolted to the bar. I settled for shimmies but it was never perfectly aligned. I bought two adjustment saddles from FLO and then the project was decommissioned.... Never got to try them out. For me the problem was always the focuser. Even Moonlites weren't up to the task. Cool build you have there now! /Jesper
  16. Hi! I used to be a great fan of the RC design but have had much more use of refractors over the years. Setting the spikes/no spikes and halos/no halos issues aside I nowadays think a good quality refractor is the all around winner. Easy to use, handle, clean, transport, store etc. Hubble and all other big ones would be refractors no doubt if it wasn't for weight and engineering drawbacks. Luckily today we have such a wide range of CCDs/CMOSs to choose from that it's easy to match scopes/cameras vs the seeing you can expect. What a delightful problem to have on ones hand! /Jesper
  17. Jessun

    Help with a OSC ccd

    I'm sure you have found this box, but it's easiest to use on a daylight image first time. Block of the scope with cardboard or something leaving just a smallish hole helps if you can't get exposures short enough not to flood the CCD. Only a few options the matrix can be set at. You'll find it!
  18. Jessun

    Help with a OSC ccd

    Don't toss the camera or indeed the images in the bin just yet. There are just a few de-bayer options to choose from. Try them all, perhaps best to try without the IR block since it you test it out in daylight the filter can cause a confusing tint on the finished debayered image. But no problem in keeping it there for astrophotography. I always had one in. Keep trying. Both AstroArt and Nebulosity can do the job. /Jesper
  19. I see this effect with my OIII filter in particular. I have to deal with it separately in processing. I almost think it's a CCD cover glass artefact, just because no other part of the imaging train is rectangular. It looks like you may want to experiment with different flats too for vignetting. /Jesper
  20. Jessun

    Guide Scope Mounting

    Hehe, calm as a cucumber. The two biggest myths I've come across regarding astrophotography concerns f-ratio and field rotation. Guiding is tricky enough as it is, with finding a guide star, getting software to work, avoiding oag prism artefacts etc etc, that it's only right to point out the single thing budding photographers don't need to worry about. /Jesper
  21. Jessun

    Guide Scope Mounting

    Your typical gem can rotate in ra and dec. Assuming pa is spot on, what part of the metal structure on the mount warps itself along this third axis? /Jesper
  22. Jessun

    Guide Scope Mounting

    I for one don't think that you can introduce field rotation by pointing the guide scope in a different direction. Only polar misalignment can cause this. But it's useful for sure to aim at the same general direction to permit the scope to track at the correct speed. Atmospheric diffraction plays tricks as you go close to the horizon. I agree that the complexity of various mounting systems add nothing really to the final result - often quite the opposite. Might as well just superglue the thing on :-D /Jesper
  23. Jessun

    An improved Crayford or not?

    I like the thinking. (Not knowing what I'm talking about really since I'm no engineer) My Feathertouches are in storage at the moment so I can't examine them. They work. I used to have Moonlite's but pretty much threw them away in anger. There were bearings all over the place and the draw tube wobbled like crazy from the get go. /Jesper
  24. Jessun

    January 29, 2018: Full disks as single stack and 13-pane mosaic

    Superb! I have no knowledge of lunar imaging but this sure looks splendid! /Jesper
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