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mytola

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    81
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About mytola

  • Rank
    Nebula

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  • Gender
    Male
  • Interests
    Astronomy, photography, karate
  • Location
    Norway
  1. mytola

    EQ6-R

    I think the site is Australian, so that price could be in Australian dollars which translates to ~1 880 USD
  2. A lot of very nice detail there, really nice!
  3. Thanks! For me the SA has worked out very well - It's very quick to set up and easy to align. With the Atik and f4 lens wide open I can get by with short subs. What I find somewhat tedious is finding the target - i spend a lot of time on this as I don't have any viewfinder and haven't yet found a good way to attach a finder scope to the rig.
  4. Finally a semi-successful attempt at LRGB after a couple of failed attempts. Focus with the blue filter on is the mantra now! Had strong wind and unfortunately the moon was full or near full, so I've got an unresolved gradient problem, but if I crop it's bearable. Also got some irritating persistent background color "blotches" that might be due to this gradient - don't really know - Any suggestions on their source are welcome. Vitals: 40 s L exposures (~50 subs) 10 s (2x2) R, G and B some biases and flats Skywatcher Star Adventurer Canon 70-200 mm f4 @200mm Atik 314L+ mostly @ -20degC Xagyl ultra slim wheel Baader LRGB filters Processed in Pixinsight - what an amazing image processing tool. I do processing of Seismic data in my day job, and this tool is very intuitive for me to work with. The 2x2 binned RGB subs were heavily undersampled, resulting in annoying black rings around the stars after registration/stacking if using the default interpolation. Found I had to use b-splines to avoid this issue. The first image is the raw lrgb and the second is a crop and rotation with some processing applied.
  5. Awsome set up! Just a side question, is that a canon lens used as the guider?
  6. Three scopes... 81 mm apo for grab and go and imaging 8" C8, my main observing scope since the min 90s 12" Orion dob with push-to. Newly acquired and still pretty untested, hopefully an at least temporary cure for the worst aperture fever...
  7. Wonder when/if we'll see diffractive optics in telescopes...
  8. Ronin, That's what I'm thinking as well, but until just now, after people have noticed this using photometry, they've marketed the scope as f/5.9. They certainly did that when I bought the scope.
  9. Thanks for your answers people! Might be some gap between the pixels, I don't know, but several people have gotten similar results that I have with different cameras. Ronin, WOW, WO has changed the spec on the page, it was listed as f/5.9 before! Dealers still list it as f/5.9: http://www.teleskop-express.de/shop/product_info.php/info/p1323_William-GTF81-5-Element-Flatfield-APO---81mm-f-5-9---FPL-53.html
  10. All, Take a look at this image run through an online astronometry app: http://nova.astrometry.net/user_images/92471#annotated This was taken with an Atik 314L+, which has a pixel size of 6.45 um. Based on this, we can calculate the focal length of the optics used to take the picture: arcsec / pixel = 206.3 * ( pixel size [um] / focal length [mm] ) Doing this I get that the focal length of the optics is 543 mm. Now, in my scope specs, it is stated that it should have a f/l of 478 mm...quite different, and in my opinion, not really acceptable. For imaging, it will be f/5.9 vs f/6.7. Can I have done something wrong here? Would be nice to have some opinions on potential mistakes. But I know others have come to similar results with the same scope and different sensors. I have sent this to the manufacturer, asking if they agree, and if there's been a mistake in the marketing, but no reply... Anyone have similar experience?
  11. I agree that some scopes that are marketed as imaging scopes really are unsuited. But there are physical reasons for the fact that companies don't make cheap fast scope for imaging I think. As I've understood for refractors, the faster the lens system, the more difficult it is to control the aberrations...you need more complex systems with more glass, which means more elements that can get out of collimation with the optical axis, thus more precise manufacturing and QC needed...and expensive low dispersion glass is needed to avoid ca. Someone correct me if I'm wrong, but for catadioptric scopes like RC or SCT, I think it's a matter of the size of the central obstruction...a faster scope needs a bigger secondary mirror, so you need to make a trade-off. Then some include a reducer, but then you have all the problems coming with a refracting system again.
  12. I'm using the EQ6 weights I have, I just had to pop out the plastic tube inside the hole to fit them.
  13. I guess it depends on budget and what you are going to use it for...I wanted something light and not too long when folded so I could tie it to my backpack. if you're just going to use it in the same place I would go for something bigger than the report 3012/72. Those Ayo mounts look very sweet by the way...is there any english sites selling them?
  14. Hi Simon, Is those 7 kg including a mount? have the report 3072 tripod I'm very happy with it. Using it visually with the skytee 2 and C8/WO gtf81, and that works well, while approaching the weight limit of the tripod, I really like the feeling of the Berlebach. Dampens vibrations really quick. Andreas
  15. Pingster, Agree, it's realy practical. I got mine used, and it had a replacement dovetail clamp on the side, so I'm comfortable mounting my C8 there. Only thing I find a little tricky is to balance the short refractor with a long eyepiece when viewing near zenith, but I guess that's not the fault of the mount.
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