Help pls, trouble understanding magnification

[Phil the Sparky]

Hi All
Well it has finally stopped rain so I took the new scope out on the deck. I found mars no problem but it is just a small dot in the eyepiece???

The scope is a sykwatcher bkp150 750 and I have a 2x barlows and a 10mm eye piece.

Do I need a different setup to see detail in mars or have I just set it up wrong?

Thanks in advance

Phil

[jjjnettie]

I'm just having a look at Mars now. I had to slot my 2.5x barlow into my 2x barlow to make it big enough to see surface detail. It's only a wee planet.

[Phil the Sparky]

Ok thanks for that jjj, hows the new scope treating you??
Might have to get some more eye pieces or barlows. I just have the 10 and 25mm and 2x barlows that came with it.

[barx1963]

Hi Phil
Your scope has a 750mm focal length, divide by the 10mm fl of the eyepiece gives 75x then multiply by 2 for the barlow gives you 150x. Mars currently has an apparent diameter of 10.4 arc seconds which is about 180 times smaller than a full moon. Even at 150x it will still be really small.

Malcolm

[Rob_K]

Hi Phil - this might help:
http://www.iceinspace.com.au/forum/showthread.php?t=86813

Cheers -

[Poita]

For mars I use the 3x Barlow or if seeing is amazing, the 5x powermate.
It is a speck of a planet.

[PeterM]

Hi Phil,

Try this software (the freeware version) it will help with eyepiece / barlow combinations and give a guide to what you may see.
If you need any further help pop in and see me at Sirius Optics on Saturday morning or over the next few weeks (Sats) you can catch Greg or I there.
http://www.telescope-simulator.com/
PeterM.

[Scopie]

400x will bring Mars up to about the diameter of a pen. You can clearly see the polar cap and some dark surface marking when the air stills. Depending on your apeture you might also need a moon or polarising filter (the latter more expensive) to cut the brightness down so you can see detail on Mars or practically any other planet.

[Phil the Sparky]

Thanks everyone for the help. Will get myself another barlows or eyepiece. The specs on he scope say it can go up to 300x's but I guess you could push that a bit further if your looking at something bright.

[pgc hunter]

You also have to keep in mind the atmospheric seeing. This refers to the turbulance caused by layers of air in our atmosphere moving in different directions and velocities. On most nights, you might find the image degrade as you increase magnification, this is because you are also magnifying the turbulance caused by the atmosphere and you'll end up with a fuzzy or "boiling" image. Some nights, you'll see this effect at only 100-150x, yet on other nights you can go double that and still get a good image when the atmosphere is stable.

[omegacrux]

I have the same scope 150x750 last night I used a 6mm and it wasn't bad so I put that on a 3x barlow even then you could only just make out detailes ( 375 mag I think ) but it would go in and out of focus very thin high clouds still fun though !