Can't see much through my new C11

[broadsword]

(Hello, I'm a newbie to SGL, sorry to start off without joining in on the welcome part).

I got into astronomy a few years ago with a Skywatcher Maksutov 127 and, although I experienced that first moment of 'but the DSO's don't look like the photos!' I soon got into the fun of hunting down the faint smudges and ticking them off. After a year or so lay-off I plucked up the courage/cash to go for the big aperture, a C11 with an NEQ 6 PRO mount. After a week or so getting the hang of polar alignement and sorting out the mount, finally got the perfect night last night to use the scope, perfectly clear and no moon. However, with something apporaching terror I found that the 6x or so extra light capture compared to the 127 was giving me effectively no extra detail at all. M81 and M82 still looked featureless, and M101 and M1 were still completely invisible. Worse, Jupiter and Mars were fairly featurelss blobs.

So, any ideas what could be wrong? Guess there's not much you can do to mess up the view through the OTA. A thought which occurred to me was whether light pollution is to blame. We live in a moderate location for LP (largeish village a few miles from Manchester). Although it wasn't a problem for the 127, could the C11 be capturing too much background light and washing out the detail? I did notice that, rather than inky black background I was expecting, stars were rather faint against a slightly greyish backdrop. Also one view picked up a strong yellow tinge from a street lamp, which hadn't been a problem before. So maybe filters are the answer?

Probably being a bit premature, but any advice appreciated......

[Daniel-K]

hi just wondering did you let it cool down?

[LukeSkywatcher]

hi just wondering did you let it cool down?

I agree. If the scope is not left outside to cool down then this could most likely be the problem.

[Daniel-K]

mine took about 2hours last night before it was cooled if its not cooled you will just see blobs as you described

[broadsword]

Well, I was outside a good three hours - in fact, at one point the objective completely misted over and had to be cleared with a hair dryer (I was actually hoping this was the problem, but to no avail!).

[Zakalwe]

I've recently bought a C11. On Mars with an 8.8mm EP I can clearly see surface detail. Jupiter will show multiple cloud bands.

Do you have a dew shield on it? It's possible that nearby lights are shining into the tube?

And very possibly it hasn't cooled suffiently. There's a big lump of glass in there, and if you bring it from a warm room to the outside then it's going to take a good while to cool.

[broadsword]

Zakalwe, see earlier reply about cool down. However, I was thinking of a dew shield in view of the misting probalem, so I'll certainly try one with a view to cutting down stray light ingress, thanks.

[Zakalwe]

£7.50 of camping mat and £3 of self-adhesive from B+Q.

Or you could spend £50 on an Astrozap

[broadsword]

Thanks Zakelwe. Saw just the thing in B+Q on Sunday as it happens.

Guess one problem I have is I've never looked through anything above a 5'' SCT before so don't really know what to expect. Anyone know any good meetings in the Cheshire/Mersyside area to go along to?

[umadog]

Do you have a dew shield? That will hopefully help get rid of the street-light glare and reduce the rate of dew build up a little.

Light pollution will make no difference to the planetary views so if you see Jupiter as a featureless blob then either the seeing is bad, the scope isn't cooled down, the scope isn't collimated, you have a dew problem (eyepiece or corrector), you're using too much power, or some combination of the above.

If the background is looking brighter than probably you're seeing the effect of a larger exit pupil. A larger scope will show a brighter image for a given power so that's almost certainly what's happening. Don't be afraid to use higher powers if the seeing supports it. A larger scope is better in light polluted as well as dark skies. The increased aperture won't cause you to see less in light polluted skies.

Do you still have the 127? If so, I'd set them up side by side and you'll see what the differences are. The darker the skies, the more the larger scope will pull ahead but should provide a better view on most objects. Also, it's possible that your expectations are too high. Most of the gain in terms of what you can see in most objects comes over the first 6" or 8". On a few occasions I would set up a 12" next to a friend's 8" and it's surprising how similar the views are. Of course there are differences in the view, but overall what you can see is rather similar.

You compared detail in galaxies and this requires experience as much as it requires aperture. Point the scope at a globular cluster: you'll notice a larger difference there, for sure. Finally, dark skies will make a bigger difference than aperture: take it somewhere dark!

[broadsword]

Thanks Umadog, I've clearly still got a lot to learn. Good call on doing the side by side comparison, I still have the 127. Just need the clouds to clear again..........

[swamp thing]

You compared detail in galaxies and this requires experience as much as it requires aperture. Point the scope at a globular cluster: you'll notice a larger difference there, for sure. Finally, dark skies will make a bigger difference than aperture: take it somewhere dark!

This is very true.

Galaxy features are tenuous at the best of times and TBH any slight haze or LP can have a massive effect on what you'll see.

Regards Steve