New scope for beginer

[barrie greenwood]

Hi guy

completely new to this game so please bear with me

ok my first scope was bought from jessops and is a skywatcher 130 mirror and focal of 900mm had it a little over a month and have been struggling with planets fuzzy and loss of detail at higher mag but im hoping the seeing is the problem

And yesterday I stumbled across a scope on ebay from a member on here call bigal1

anyhow bought this as it was a decent price and spoke to him at length he recommended this site

what I have found was this scope is also a sky watcher but a 130P and only 600mm focal but on a side by side it appears much more sharper on land test than the larger scope

My question is why is it the mirror or just a better scope in general just want to know which is the better one

Thanks in advance Baz

[Dave Lloyd]

Hi and welcome. Presumably the first is the 130m, this has a very good report on f.l.os website so it's a bit puzzling if it doesn't perform for you. Perhaps it needs collimating, a fairly straight forward process but as I'm a refractor guy others can it explain it far better than me. The 130p is another excellent scope. I'm sure you'll get sorted out in pretty short order on here.

[Timebandit]

Hello and welcome to SGL. From what you are saying both scopes are skywatcher 130 ,but with different focal lengths. In theory I would of thought the longer one of 900mm should be a bit better on smaller object's(a slower scope). But from what you are saying the 600mm focal scope is giving better views(faster scope)

There could be a number of factors, have both scopes been collimated correctly? Maybe the longer focal lengh scope is not very well collimated, well the shorter focal lengh scope has had its collimation adjusted spot on.

Maybe you are using eyepieces that one scope likes better than the other one. Eyepieces can react differently in different scopes giving different quality of images

Or maybe you just have different build quality in the scopes, maybe you have a poor mirror in the one withh fuzzy views but a good mirror quality in the scope giving good views. The quality of mirrors can vary from batch to batch even in the same scope products. 

I hope the above may be of help and could answer your questions☺ 

[barrie greenwood]

Hi

Thanks for the reply it is the 130m that's right is it worth keeping both of them ?

As for collimating haha yeah ive smashed my head to bits with that one but eventually got it and now use a combination of a laser and a cheshire tool

the one puzzling thing about it is if I set the secondry  mirror so the three clips are visible and its bang center with the Cheshire tool then use the laser tool it never hits the center of the prmary mirror now ive tested the laser on V blocks and that's fine so I then readjust the sec mirror to place the laser in the center of the primary and then recheck with the Cheshire and its off center again ??

Any ideas

Regards baz

[Timebandit]

Hello. As for collimation I use a collimation cap so a bit of a different method than you are using . So my knowledge is a bit limited on your chosen methods . I do know sometimes people collimation the hell out of scopes following and trusting a laser only to find out the laser is out and itself needs collimation(lasers really do need to be accurate to assist and get good results overwise they are just misleading). 

If it was me I would chose maybe  the cheshire method first and collimation the scope to as accurate as possible(do not then readjust with the laser). And then do a star test to check collimation using a high power eyepiece (more info and pictures on the web to what type of resultt) A star test will confirm how good your collimation has been. 

I hope the above helps☺

[barrie greenwood]

Yeah that what my plan was just waiting for a clear break in the cloud hmmm that could be sometime up here

Thanks for the replys guys much appreciated

Best regards Baz

[happy-kat]

Your laser collimator could actually need collimating and that is why it gives different results to the Cheshire.

There is a chance the second telescope you bought could have a parabolic mirror, the label on the side would likely say 130P. This is technically a better mirror then the spherical in the 900mm long 130M but your 130M should I think still be pleasing images.

[barrie greenwood]

Hi

Yeah it is a parabolic in the short one I think your right and most of my issues are down to the seeing

So what's the difference between the two I. E focal length I don't really understand why the longer focal as opposed to the shorter focal what in real world will the longer be better than the shorter and vice versa sorry to be a pain but I've jumped in feet first and I'm out of my depth

Regards Baz

[happy-kat]

The length is used to calculate magnification with eyepiece.

900mm / 10mm gives x90

650mm / 20mm gives x65

So the longer telescope gets you higher magnification from the same eyepiece.

The 900mm will be best for Moon and planets and bright clusters.

The 650mm will be best for DSO that are less bright.

The telescope focal ratio is length / aperture so the 650mm is f5 which is faster then the other at f7. The lower the number the more light that is kept. The longer the tube the light is more dimmed as it reaches the end of the path it travels before you see it in the eyepiece so fainter objects are more difficult to see.

[barrie greenwood]

Ahh right I see ( NO PUN INTENDED) so the shorter the tube the wider the fov more suited to deep space and the LONGER tube better suited to planets etc

Getting there slowly ?

Thanks happy Kat

[happy-kat]

Just updated my post with more info.

[barrie greenwood]

Makes sense as I've struggled to find M57 with the longer tube spent hrs looking for even a faint fuzzy blob I need the cloud to clear so I can take a look through the 650 and see if I can find it then

Next one dies any one know where u can get hold of a goto handset I know there is a buy and sell section but as a new member I can't get access as yet

Thanks guys

[happy-kat]

You need to use averted vision for DSO when finding hard to see.

Your tripod has a motor but you can't fit a goto handset if it is the tripod that I think comes with the 900mm.

[barrie greenwood]

No its the mount in the smaller one it's a skytrack I think

 

[happy-kat]

I would suggest you download Skywatchers manual for the mount/telescope you have as that will say what/if there are upgrades for the mount available.

[barrie greenwood]

Thanks again yeah I've done that and there is a goto for it

I've had a word with my local astronomy center in bacup and the guy there called Peter drew is a top guy has offered me the loan of one to try which is very decent of him to be honest.

Also collimating the both of the scopes and spend a good bit of time on them both now I'm happy with the results and the images are about on par with each other and not much in it just a little wider fov on the shorter tube

Thanks guys