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Flocking a 250PX – is it worth it

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Hi all,

I've already posted this on my blog, but I thought I'd share it here as well, as I know it's something of interest to a lot of people. I spent a good chunk of last Saturday actually flocking the scope, and most of Sunday morning re-collimating it, and on Sunday evening I managed an hour and a half under the stars checking out whether it made a difference.



I set up the scope for about 8.30, and got straight on with viewing Jupiter. The scope hadn't had time to cool properly, and the seeing was somewhat unsteady, but the GRS was very obvious at x250, the brick red colour also obvious, but little other detail.


Deciding that I stood the best chance of detecting whether the flocking made a difference would be when viewing faint objects, I swung the scope round to M101 and then M51. The former was little more than a smudge, but the latter had clear signs of spiral arms and bright cores, definitely a little more contrasty than I remember. 


The Sunflower galaxy in Canes Venatici was very bright, but had little detail on show (I put this down to the seeing being unsteady, and the galaxy being still quite low). 


The Leo Triplet was brilliant. Nice and high, all three galaxies were bright and sharp in the 24mm MaxVision (x50). NGC 3628 was very obvious.


I panned down through the bowl of Virgo, spotting over a dozen galaxies, but I've viewed this area before with better contrast and detail. I put this down to the seeing, and the fact that the constellation was still so low in the east.


As galaxies were on the agenda for the evening, I thought I'd go for the nine shown in the bowl of the Big Dipper in the Sky & Telescope Pocket Sky Atlas (prompted by a recent SGL post). I managed four of the nine (I'm pretty definite I got the lower ones - NGCs 3982, 3998, 3898 and 3780 - the latter, if I'm right, mag 12.65 and an incredible 146 million light years a way; and a new record for me!).


I decided to try a couple of star clusters (the Owl and Double in Cassiopeia and Perseus). Both were very clear and sparkly, with, I'd say, a definite improvement in contrast. Subtle, though ...


Finally, I swung the scope round to Orion. Wow! This is where the difference was immediately  obvious. Although I didn't see more in the Great Nebula itself, de Mairian's nebula was brighter than I'd ever seen it, and just below it, the Running man practically leaped out at me, a very obvious darker band sandwiched between two brighter sections, plus other detail/structure. I swung the scope up to where the Horse head nebula should be (never seen it), and again wow! Although I didn't spot the HH itself, there was very obvious dark nebula in the area, and I feel sure that, had I had more time, I'd have bagged the horse.


So ... flocking: is it worth it? I'd say definitely yes. The obvious nebulosity around Orion itself makes it a no brainer, and I feel pretty confident that it helped with the Leo triplet and the four out of the 'nine in the bowl' of the Big Dipper. As for star clusters, the jury's still out, and I think it would take a side-by-side comparison with an un-flocked scope to really be sure.



Hope you find that useful.


Edited by kev100
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Nice report Kev and some excellent objects in your report. I recently bought a 12" Dob and one of my first tasks was to 'flock' the upper part of the scope. I had previously flocked a 6" and 10" Dob and I did find that the contrast was slightly improved. The other night I had serious frost on the outside and inside of the tube but only on the bare metal part. The flocked area was clear.

As regards the HH I wish you luck because it is so hard to see. I have only viewed it once and that was with a 16" Dob with a 19mm Panoptic EP and an Astronomik O-III filter at the SGL star party a few years back.

Must now finish flocking the bottom end by the primary mirror.

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Sounds like your a happy man,tell me what is your sky like as far as light pollution goes and did you flock the whole scope.

I have been thinking of doing this on my scopes,but just hav,nt got round to it yet.

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Thanks guys,

Hi Paul, I'd say my sky is pretty good, really. Andromeda and the Perseus Double Cluster are usually naked eye objects, for example, more so obviously when higher in the sky. Seeing was a little unsteady on the night, though, and there was a chilly breeze. I did flock the whole tube. It was fairly easy, really, and a rolling pin really helps keep the material straight and bubble free.

Mark, I know the HH is probably going to test the 10 inch, if not be beyond its capability altogether, but I was surprised by the dark patches in and around where it should be. Never seen anything like that before, so fingers crossed :)


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Kev I always use this diagram to try and view the HH. I am certainly going to have a go with the 12" and my Thoudsand Oaks H.Beta filter.

I hope to be able to flock the whole tube but its a solid tube and I am not sure my arms will reached the middle part.


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Hi Mark,

Yep, that's a useful diagram, and showing pretty high magnification. I was using my 24mm EP (and without a filter) which gives x50, so I know it's not possible to see the HH with that, but as I said, I was very surprised at how much there was in the area, when previously there was nothing. Dark mottling, I guess is the best way I can describe it ... darker patches, lighter patches, all pretty faint, to be honest.

I followed a Cloudy Nights post when I did the flocking, and did the middle section first. Lining up to the seam in the tube helped, as did using a rollin pin, as I said, but the 250 is only 1200mm focal length, so wasn't too hard to reach in there.


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