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About BGazing

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  1. Pretty interesting news here until the end of the thread.
  2. If they are top and bottom (blue top red bottom, inverted in newton), it's atmospheric dispersion. If the target is low enough and your aperture big enough, it becomes visible. Other orientations are chromatic smear due to poor seeing. You may get both of them together. I've checked your Jup/Sat observing thread, dispersion is easily visible in the pictures you have taken...
  3. Yes, you will occasionally see chromatic 'smear', when the chroma is smeared in the east-west direction, or when you correct with ADC and the top blue and bottom orange disappear and then you get chroma occasionally 'dancing around' the edges but as soon as the seeing settles it disappears. But you can play around with it...return levers to 0 and suddenly there is unmistakable top blue bottom red. Tiny correction and it is gone and everything looks a bit better. We talk about strehl this spherochromatism that chinese vs premium vs doublet vs triplet but what AD does on planets is that it basically smears those subtle Jove colors all over the place.
  4. Played the whole night with ADC and binos on C8. The amount of lever correction needed with 1.25GPC is tiny, but results in a detectable improvement. Moons are elongated dispersion dots and when corrected become dancing fuzzballs (seeing, meh) without dispersion. One can also see AD on the Moon this low, while cruising top part it has a sliver of blue fringe (very thin) and the corresponding orange sliver at the southern pole. Seeing was not that spectacular, tbh, but what can one expect at 23 degrees in meridian.
  5. You can simply test it against the background...you will find the link in one of my earlier posts to a CN thread where the test and explanation to the test.
  6. 150x is perfect for that aperture, 200x if seeing is really good, or even higher if the floaters do not bother you.
  7. Fantastic prominence this morning...phone shot does not do it justice.
  8. 100 deg C and you have to heat them over 30 minutes, so it makes sense to get at least a few of them that need dehumidization.
  9. I did not measure, but then again when I use it in mono I use it with PM2.5 and I do not have to remove extension on Tak. Just use some barlow or (ideally) PM2.5 with t2 connection to ADC...if you happen to have one. Below f/10 you will get astigmatism. I would bump up even those f/9 scopes (DL?) although it just might be enough.
  10. Essential? Well, having a scope and an EP is essential. But really, in a small frac you might give it a pass...and in a bigger scope you will clearly see AD. It's one of those things when you remove it and you go 'a-ha!'. Sort of like when you go to your ophthalmologist and you think they got your prescription right and then they do the little astigmatism correction and it just gets better... The cutoff altitude may vary by aperture. Jove at current altitude takes a particular AD hit, just the nature of the target.
  11. Tried some more things last night - seeing was again meh, clouds came and went and distant flickering of the thunderstorms did not look like I will be observing much. C8 was not used, again only Tak with binos, with and without ADC. At around 100x in binos you can see AD. At around 150 it is not so pronounced (dimming, i guess, but it is still there). At 100x the moons have a bit of AD elongation. ADC clears that up and they become points. You certainly can use Tak without ADC and it is not overwhelming, but it is there and it blurs the picture. Also, the seeing somehow appears better with ADC (this was also observed by the others). Jury is out there if seeing seems better subjectively with or without binos...there's certainly less eyestrain when viewing through the running water with both eyes. More measuring stuff...when using binos without ADC I finally put the GPC in front of the diagonal to simulate 130x...and, believe it or not, it provides TOO MUCH back focus, I racked focuser out all the way with my extension and could not come to focus. It quite possibly would focus with the normal Tak extension (I use 47mm clicklock instead), or using normal diagonal with ep holder and 1.25 nose on Binoviewer, but at the expense of more magnification as per calculations above (approx 3.8x altogether). But if you are in dire need of backfocus, there's your solution, just put it in front of the diagonal and you are good to go.
  12. Yes, MK3 PA looks very elegant except that it has been unavailable for quite some time. I like the one knob adjustment. MkIV with a bubble level would be perfect.
  13. Well your astigmatism was a factor of the f/l. You have to push it past f/10 to do away with astigmatism... But yes, Gutekunst is a proper ADC for that scope.
  14. Have you used barlow/powermate with your ZWO/ADC? I never used it with fracs without PM2.5? I do not mind optical path and I love Zeiss/T2 system, it is just that Baader does not list if you are getting any additional optical path with it vis-a-vis the T2 coupling nut... I am just curious...
  15. I know. I was wondering whether the 'default' bayonette system of Baader binos adds optical path in comparison with the 'default' T2 coupling nut solution. The bayonette system I linked is 15mm optical path, that is for sure.
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