Beautiful clear skies but...

[mrwhippy14]

Hey guys. I set my scope up yesterday in Essex where the skies were perfect. I headed out at 8pm and finished at around 9.15 pm.

The scope was left to climatise for an hour (can't spell correctly.)

For the first time I aligned the scope with two stars. Betelgeuse and Polaris.

The first thing i headed to was a nebula that was perfectly in view. The Orion Nebula. I had only seen this in my binos before. I know not to expect what is in Star books in terms of the colour and clarity. But all i say was a white haze . I focused the Nebula in my 20mm ep with a barlow. Then i risked using my 6mm with the 2 x barlow. Awaiting the reddish/ purple colour i had seen in star books / programs ive been revising from.

I got a lovely view of the Pleides. However the colour wasn't very vivid. More white in colour than the blue i have heard of.

I got a view of Sirius that was above the horizon and a fence in my garden. It was shing a strong yellow but a blue red tinge was eveident.

I have heard of achromatic aberration i think. I know there are many varaibles such as the LP, the height / turblance in the night sky. But I really thought i could get a better view of the orion nebula. But i am happy that i managed to Align the Goto correctly (sometimes it was a little of double star clusters i searched for but on the whole ok)

Also I am one more step forward than my previous attempts to go outside. I wont be giving up any time soon but any help / tips / things to buy for my scope would be great. Thanks alot guys.

(i know my scope isnt the best so a new investment may be on the horizon this year ... excuse the pun.)

[John]

The photos you have seen are very misleading I'm afraid. Scopes and our eyes just can't rival what CCD's and modern processing can produce. Deep sky objects do appear as grey patches of light - one or two can show faint tints of colour at best but those are exceptions and only in large scopes.

You were also using too much power on the Orion Nebula - it's a large object so low or medium power (say 30x - 50x) is whats needed.

Your 102 F/5 achromat will show plenty of false colour but it should only be an issue on brigter objects - the moon, planets and the brightes stars - it does not affect deep sky objects noticably.

Not seeing views like the photos in books and on the web is a common issue with newcomers to the hobby I'm afraid but I hope you can get some enjoyable views anyway - when you consider what you are seeing it's quite awesome.

[mrwhippy14]

Thanks, yep i was still in awe in what I could see. The fact that I had this in my scope was very pleasing. I'll keep trying and testing different combinations of my ep's to give me better views.

[mrwhippy14]

Have you heard of a Fringe Killer. Would that help on planets etc. ?

[John]

Have you heard of a Fringe Killer. Would that help on planets etc. ?

It might help a bit but they do introduce a "tint" (generally yellowish) of their own.

To be honest a 102mm F/5 achromat refractor is best suited to low - medium power viewing of deep sky objects, clusters etc as the false colour gets intrusive above around 100x. It's not just your scope, false colour affects all achromat refractors to some degree - the longer the focal ratio (eg: F/10 rather than F/5) the less you get but you have to have an F/15 102mm to more or less escape from it - that's a focal length of 1.5 metres !.

You should still get some enjoyable views though.

[Carbon Brush]

Our eyes only resolve colour at fairly high light levels. We see the day in bright colours, but at night,looking around even with a full moon, it is very much a 'black & white' view. The camera can keep showing colour down to low levels.

So while the Orion nebula really is bright red, we see it as misty white. If you had a really big scope to gather lots of light, there would be enough to start to show colour.

In the UK dirty skies, we tend to think of stars as being mainly white, with a few that have a bit of colour. If you go to the clear skies of a hot dry country, a lot of the stars become coloured. This throws me every time I am fortunate enough to go on holiday to the likes of Egypt. Not only are the stars in the wrong place (latitude) but they are bright and coloured. I remember once getting confused looking at Antares - Surely it had to be Mars with that colour and brightness!

[John]

I've usually found binoculars better than scopes for showing star colours. Betelgeuse looks very orange through binoculars - but is a little more "washed out" with a scope. False colour does tend to mask the colours of brighter stars as well, unfortuntately.

This is starting to sound a little negative but it shouldn't be - your scope is capable of showing some very nice views but, like other scope designs, it has it's strengths and weaknesses.

[mrwhippy14]

Thanks guys. Greatly explained. I am going Turkey in Sept. Maybe i'll bring the binos with ive heard the skies are great there :S apparently.

Thanks for the heads up on the colours . I'll bear that in mind. I'm thinking of going to my first astronomy club on Weds.

[John]

Get your scope to Turkey if you can - a 4" scope under really dark skies shows wonderful views of deep sky objects - it's almost like doubling your aperture. You could always take the scope of the mount and put it on a decent photo tripod - the 102mm F/5's are pretty light and compact.