Blurry Planets - Baader x2.5 Barlow

[Dan Watts]

Hi all,

I wondered anyone can help...I'm still and learning as I go and by getting involved on here.

I recently bought the Baader x2.5 Barlow as an add-on for my 8-24mm Baader as I thought this would be the best way to go for planetary work with the scope I have. I really wanted to get as close as I could to seeing the lines on Jupiter, Mars and its polar caps etc.

I have used it a couple of times and also with a Baader Neodymium IR-Cut Filter but found that no matter how much I tweak the focuser it still is a little blurry and no where near as clear as I would of hoped...Whether i'm never going to get a great view of these planets as I am thinking, would pushing the zoom too far and the conditions (even though they are clear) cause this?

I admit, that when I look at it without zooming in too much, it does look good, very bright, but good...As you zoom in too far, is this where the problems arise even if conditions aren't that bad?

I have collimated the scope using a laser so I know it can't be that...Thing is when I look at the moon I can get in real close and it like viewing in HD so I know it's not any mirror or scope issues.

Maybe a fixed focal length would be the way to go...mmm, I'm not sure.

Any views or assistance would be greatly appreciated.

Dan.

[Thirdway]

What scope do you have?

I have a 200p and with the 8mm zoomed in it can look a bit blurred, depending on conditions.At 7mm the telescope has just about reached its limits, so if you are using a scope of that size with a Barlow then the lens is magnifying greater than a 4mm lens which would be way to much for most scopes, never mind an 8" Newtonian. Take into account thermal currents, collimation faults, atmospheric distortion, a bit of wind sway and moosture on the lens and it's going to be really bad

I usually mag at about 9/10mm max, nice and clear. If you have no street lights and can track the planet then you can easily see the lines on Jupiter and the Cassini division on Saturns rings. Mars I have had better results defocussing using slightly.

[Dan Watts]

Hi,

Sorry, I thought you might have picked my scope etc up on my Signature...It's a Orion XT8.

yeah, you made a lot of good points there, there are lights from people's houses etc...I guess as well, with the moon being at near enough full moon, that isn't going to help either! lol.

I think maybe i'm expecting miracles to happen...I think more patience is required!

Thank you for your help with this

Dan.

[assasincz]

I am currently in a market for some Baader Orthoscopics...having read various articles, I believe this is the way to go in planetary observation.

[John]

I think you are trying to use too much magnification. Without the barlow the zoom is giving a range of 50x - 150x magnification. With the barlow (2.5x) you get 125x - 375x. The max that would be useful on Jupiter would be around 200x, on Mars perhaps 250x. More than that in things will get larger but blurry and less defined, mostly due to the seeing conditions. That assumes the scope is in good collimation and is fully cooled.

[E621Keith]

Have you check collimation on your scope. In a good night a 200mm f5 should be able to handle 250x. I haven't use the Baader barlow so I can't comment on its quality.

The seeing last night was very poor, none of the scopes at my astro club meet could pick out any details on the planets. If you were observing last night, may be give you should give it another go

EDIT: Sorry, I just realised the orion is a f6. 300x (4mm) is a bit much for most nights in UK

[Dan Watts]

Thank you for all your replies...As some of you have mentioned, I maybe using a little too much magnification I think.

I have prob seen too many pictures of some really good quality pics on here and thinking I can just see every minor detail...At the end of the day, my scope is only an 8", not the Hubble! lol.

Patience id def a virtue, I could really do with going to some dark sites to really get an idea of my scopes capabilities...The back garden has a lot of pitfall's with next door neighbours lights, streelights out front etc.

Thank you all again for your time

Dan.