Looking at Mars.

[Myfeetapontheground]

So last night I had some great views of mars. (before the moon came up anyways). I was using a Orion XT8 with a 2X Barlow and a 6.3 mm Plossl eye piece, but I just could not get a clear image. It would just stay blurry. Any suggestions?

[Mr Q]

With the barlow and the 6mmEP, sounds like you were using too high of a magnification. For most scopes, a 4mm EP is the highest usable mag. and a 6mm should work better. Let us know how the 6mm alone worked out on your next observation.

[Myfeetapontheground]

I never even thought about that. I just left the Barlow on there from when I was centering it with a 25 mm ep. Thanks for the advice. I will definitely do that next time.

[Moonshane]

three things to consider :

cooling - ensure your scope reaches thermal equilibrium by leaving outside for maybe an hour before use.

collimation - ensure you check collimation before each use and adjust as required.

magnification - your stated set-up (assuming a focl length of 1200mm) would have been 1200 / 6.3 = 190x but x 2 for the barlow so 38x. This is generally too much nd as stated 190x will be a lot better and possibly the max on many nights.

hope this helps.

[Myfeetapontheground]

This probably makes me look stupid but I am not sure how to check collimation.

[knobby]

Very rough check is to point are a bright star and wind out of focus ... you should see a massive blur with your secondary mirror and spider in the middle! If its not in the middle its not collimated accurately. Rough but it gives you an idea

[Myfeetapontheground]

OK thanks, I will try that tonight. What do I do if it is not correctly collimated?

[Skybrowser]

You'll get a few answers on collimation on here but to see it being done, check it out on You Tube. Lots of vids on there and it's really quite simple. You will need a cheshire eyepiece or laser collimator and once you get the knack, it takes about two minutes or less to get done. Makes a big difference if it's way out to start with.

[Moonshane]

you really need a collimation tool like a Cheshire. a really quick check is look down the empty focuser and get your eye positioned so that the pupil is in the centre of the primary donut. if the mirror clips are not centrally positioned in the secondary then you will need to adjust. if you have never adjusted it (I do this each time I observe) then it will improve your views for sure.