help with images not focusing

[jokerb19]

So i have a question for the group. Last year i purchased an XT-8 and have used it a little since then but mostly for planetary work. I have found that on deep sky objects, i can never really get a good focus on them. They are extremely fuzzy, to a point that i can tell something is there, but not make out what it is that im looking at. This happens at any magnification using any eyepiece. I have these eyepieces

http://www.amazon.co...ds=orion lenses

I do my observing in an extremely dark setting, west deserts of utah. Any ideas/help would be greatly appreciated. I undertand im not going to get extreme detail without getting into photography but i really hope that i can at least tell a pinwheel galaxy is a pinwheel galaxy as opposed to just a blobby haze like it is at this point.

Thanks in advance!

[Carl Reade]

If the stars are focusing that sounds normal as to what you will see. To bring out more detail you require more apature and of course cameras see a lot more.

Cheers Carl

[ronin]

How good were the planets?

Was the banding on Jupiter clear.

The scope is f/5.9 so you should be OK with reasonable eyepieces and not have to go to extreme's.

Not 100% sure of the Sirius plossl's, had one and gave it away.

Have you checked the collimation of the scope, it may have moved and needs realigning.

Basing this on the fact that you mention using it last years and viewing at a dark site which I half suspect means transporting the scope there. All the nice bouncing around.

Are the galaxies you are looking at ones where you would realistically expect to see any structure?

I assume there is no dew forming on the mirror, to distort things, and that the scope has cooled down.

Could you borrow another eyepiece, something like an AT Paradigm or a TV Plossl. If still indistinct in one of them then it at least eliminates the eyepiece as the problem area.

Cannot think of much other then check and reset everything to the optimum position then try it again, but 8" f/5.9 should deliver reasonably sharp views. Have you tried it on Saturn at the same time just in case the atmosphere is turbulant as Saturn would come out a little indistinct also.

[acey]

What the others have said.

Focusing is what you do on stars and planets - nebulae and galaxies always look fuzzy (though sometimes there are sharp details in them, e.g. stellar cores or faint involved stars). If you're happy with your planetary views then your DSO views must be OK with regard to focus. Just a case of getting used to the look of these things.

With an 8" scope at a dark site you might just be able to make out the spiral structure of M51 at high power. You also might be able to make out the S-shape of M33 if you're patient. The sort of detail you're more likely to notice is overall outline (e.g. M104) or dark lanes (e.g. M64, NGC 4565).

[bingevader]

Very similar 'scope to mine.

I tend to use a nearby star to achieve focus and then bring the fuzzy in.

I mostly use the 32mm and 18mm on DSOs, because I find anything higher just results in a faint fuzzy.

You may get away with more if your skies are really dark and clear, it's transparency your after, but I'm delighted with the views from my back garden.

I concur with acey, I tend to get a good contrast from core to edges, some structure and a bit of detail if I'm lucky.

And that's good enough for me, splendid in fact!

Cheers

[DMA]

"west deserts of utah" you can't get much darker(very jealous).

Agree with others about eyepieces,don't skimp on them remember eyepieces are a long term

investment that could last you the life of your hobby mine cost more than the scope.

low f number scopes need to be well collimated to see detail in dso's.

Invest in a good collimator I don't trust the laser ones I have a Cheshire, I only have a

helical focuser so it's not worth me investing yet but maybe you should invest in a

autocollimator from catseye or farpoint.

Hope this helps

Dave

[jokerb19]

Awesome advice guys! I have not collimated since i got the scope, so i checked that and it is close, but not right on so im going to start there. Then im going to save for better eyepieces and a larger scope. I was actually looking at M51 the other night and all it looked like was a large blob and a smaller blob. Maybe that's all im going to get with an 8", i have a bit of aperture fever and i want ultimately a 12 or 14 inch dob. The planets look good, and i can see the banding on jupiter, but i cant really remember getting a really good focus on those either. I honestly believe that collimation will solve my problem. Thank you all

[jokerb19]

"west deserts of utah" you can't get much darker(very jealous).

Agree with others about eyepieces,don't skimp on them remember eyepieces are a long term

investment that could last you the life of your hobby mine cost more than the scope.

low f number scopes need to be well collimated to see detail in dso's.

Invest in a good collimator I don't trust the laser ones I have a Cheshire, I only have a

helical focuser so it's not worth me investing yet but maybe you should invest in a

autocollimator from catseye or farpoint.

Hope this helps

Dave

Just out of curiosity, what are some examples of some good eyepieces i could start saving towards?

[Moonshane]

collimation would not normally affect low power views of fuzzy objects like galaxies too much. if off slightly it affects high power views of brighter objects a lot more.

I think your 'issue' is one of managing your expectation slightly. if you can see a fuzzy blob, this is normal but with darker skies (like yours) you can only improve a lot of things with more aperture, and only then to a point. with faint objects it's more about describing what you detect rather than what you see. also, make sure you use as dim a red torch as you can (even red torches when bright affect night vision) and obviously don't use things like mobile phones/laptops unless in night mode and even then.......

[jokerb19]

collimation would not normally affect low power views of fuzzy objects like galaxies too much. if off slightly it affects high power views of brighter objects a lot more.

I think your 'issue' is one of managing your expectation slightly. if you can see a fuzzy blob, this is normal but with darker skies (like yours) you can only improve a lot of things with more aperture, and only then to a point. with faint objects it's more about describing what you detect rather than what you see. also, make sure you use as dim a red torch as you can (even red torches when bright affect night vision) and obviously don't use things like mobile phones/laptops unless in night mode and even then.......

Im starting to think that this may be an issue too. I expected everything to be black and white, but i thought i would at least be able to see structure in the galaxies, like the arms on a pinwheel, or at least some dust lanes. So far nothing more than blobs. If thats all im gonna get, then that is that, and i need to start looking into astrophotography if i wanna see more/better. Curse these weak human eyes.

[DMA]

Hello

This link will help you with what you can expect to see when looking at m51 with good

dark sky's and good atmospheric conditions http://www.clarkvision.com/visastro/m51-apert/index.html

TeleVue eyepieces are the ones that everyone seems to aspire to own even their std plossl

range are a cut above the rest but I'm too new to this to give to much advise on eyepieces.

many eyepieces have been reviewed on this site just do a search.

Also the longer you look at a dso the more detail your eye will pick out make sure your eyes are

well night adapted as said by MoonShane and your scope cooled to ambient temp.

Dave

[jokerb19]

Hello

This link will help you with what you can expect to see when looking at m51 with good

dark sky's and good atmospheric conditions http://www.clarkvisi...pert/index.html

TeleVue eyepieces are the ones that everyone seems to aspire to own even their std plossl

range are a cut above the rest but I'm too new to this to give to much advise on eyepieces.

many eyepieces have been reviewed on this site just do a search.

Also the longer you look at a dso the more detail your eye will pick out make sure your eyes are

well night adapted as said by MoonShane and your scope cooled to ambient temp.

Dave

WOW. My view was no where near this good. No where near this defined. It was worse, far worse than even the 6 inch visual indicated. Im going to wait and see if atmospheric conditions and a cool scope produce some better results. Although it was near perfect darkness, i dont remember what the atmospheric "seeing" was rated at for that night.