First use of scope

[rogergps]

Hello all.

Just managed get out for the maiden use my first scope (SW Heritage 130p). Clear skies, so good night for it. I managed to see Jupiter fairly well - could clearly see cloud bands at 63x. Couldn't see any colour but wasn't expecting to. Very happy with Jupiter.

Then went to M31. Bizaarly, I could see the core brighter than with my 10x50 binos, but couldn't see as much of the surrounding "smudge". Moved to Plaeides and again couldn't see this as brightly as with my 10x50s. Not sure if I am doing something wrong or if this is what I should be getting.

I had a quick bash at collimation but didn't do the step by step - just checked I was seeing my eyeball down the middle. Focus on Jupiter seemed fairly good so I assumed it was all good.

Any tips/guidance welcome.

Thanks

R

[Aussie]

Hi I've just started using scopes myself so this is probably wrong advice but hey I'll give it a go. As scopes increase in magnification images become darker so your scope which is viewing at a much higher magnification then your binoculars has a dimmer image. Try viewing using the lowest magnification that you are happy with and see if the image is brighter.

[pvaz]

Maybe you're squinting when using just one eye to look through the scope. Try a towel or a black cloth over your head so it will block all light. That way you can have both your eyes open.

It may sound silly but it works. Just the other day I was struggling to detect the great red spot in Jupiter and, once I stopped being lazy and went inside to get my black cloth, it just poped out.

[rogergps]

Thanks guys. Didn't even think about the magnification, even though I have been told about it several times. Thanks Aussie. Will use the 25mm eyepiece which will bring me down to around 25x (I think).

I reckon I was squinting aswell so this may well have affected the view.

Thanks again

R

[rogergps]

Not sure how far this is possible so bear with me.

How far can you practically reduce magification down to with a small telescope like a 130p (F/5)? If I wanted to increase the brightness of an object without being too fussed about magnification, could I reduce down to say 15x or 10x mag. Just thinking about getting as much light/brightness in a possible.

I know the bigger the apeture, the more light I'll get i.e. get a bigger scope. But right now I'm limited to 130mm apeture so just seeing how far you can flex the variables.

Many thanks for the help

R

[matt c]

Don't forget that M31 is so large in the sky it fill your entire field of view, it might be difficult to distinguish the body of the galaxy and the sky

[matt c]

Personally stick with the 25mm, they say that if you use a piece lower than that with f/5 the exit pupil becomes larger than the pupil of your eye, so in effect your wasting light. Maybe the more experienced guys can go into more detail about this than I

HTH

[BazMark]

In the SW 1145P scope I used to have, the Pleiades used to look their best at about 20-25x. They would all fit in the field of view and looked magnificent. In many respects I wish I still had that little f4.4 scope as my Mak127 even on it's lowest power (37.5x) and with it's much smaller FOV looks right through the middle of them. They actually now look better through my 10x50s. In time I can see myself going back to an f5 or 6 scope for the nice wide FOV.

[Chris H]

With the 25mm ep the Plaeides in your 5 inch scope should look better than with the bins. Yes it's more mag and your looking with only one eye but you have more than twice the light gathering ability of the 10 x 50's.

The lowest mag you could go down to would be x20 with a 32mm Plossl, this would give you a whopping 2.4 degree field of view. Enough to fit in all of the Plaeides and over half of the Andromeda galaxy. Beyond this the exit pupil begins to get over 7mm and you'll just be wasting light.