HELP!!!!!

[DAVPPK]

Hi to all, I really need help here. Yesterday, I looked at jupiter with my scope (see sig.)...It was there, a disk with 3 moons...problem being I could see NO detail in the bands whatsoever , even with the highest power on my EP (see sig.)...

also, the top of jupiter war reddish, and the bottom was blueish...again, why ???

I'm also having trouble pointing my scope, the finderscope is aligned, but just doesn't show the object when seen through the EP .

All help appreciated!!!

Regards,

Dave

[John]

My guess is that it might be the fact that you are using a low cost zoom lens with an F/4.8 newtonian - a scope which is pretty demending on eyepieces. The zoom eyepiece is not the optimum for planetary contrast and detail and may also be introducing some false colour into the image you see (the red and blue you are seeing on Jupiter).

Thats my guess - see what other ideas come forward.

On the aiming of the scope, if your finder is aligned accurately with the scope then something in the finder should be in the field of view of a low powered eyepiece in the scope. When setting the scope up you should align scope and finder using a very distant test object - miles away rather than yards away.

John

[Beulah]

John is most probably spot on - coupled with tempermental seeing with Jupiter - I haven't yet had any steady seeing to see any detail for long enough of the planet's surface.

[GazOC]

The red at the top/ blue at the bottom is probably caused by atmospheric refraction because Jupiter is quite low in the sky.

[peeceeTal2M]

Has the collimation been checked? The orion's collimation screws are not protected at the rear and its easy to knock a wing nut and put the collimation out! Also i agree with what John says, the Orions can be unforgiving with cheaper eyepieces and that is more than likely the cause of the colour your seeing. It also sounds as if the finder is not perfectly aligned, I always used a crosshair on the eyepiece to get good alignment.

[Psychobilly]

Possibly using too much magnifaction (to short a FL EP) for the conditions as well?

[DAVPPK]

Its only 60x I was using (21mm)

[Mikea]

The red at the top/ blue at the bottom is probably caused by atmospheric refraction because Jupiter is quite low in the sky.

That's interesting. My wife commented on this when we were viewing Jupiter about a month ago - still very low in the sky. Being supposedly partially colour blind (!!), I hadn't noticed.

[DAVPPK]

But did you see any surface detail??

[Mikea]

I could see the two dark bands, yes.

[nitram100]

Hey David,

I have the same scope as you and my first experience was similar, no detail....just a white blob with 4 dots orbiting it. Then i learned how to collimate as it as CRUICIAL with an F4.8 newtonian, especially for squeezing out every bit of planetary performance you can from it.

After i had learned how to collimate, i could see bands, the great red spot and shadow of the moons on the planet clear as day.

I would strongly advise you to buy something like this

Collimation - Cheshire Collimating Eyepiece

It's the same one i have and it's great. Also you need to centre mark your mirror if it isn't already marked., which sounds daunting, but it isn't difficult at all.

Read this webpage and it will show you how to easily centre mark your primary mirror. Once you've done all this the planetary performance will be much better. I couldn't even see the cassini division through my scope until i had learned how to collimate.

http://codeidol.com/other/astronomy/Scope-Hacks/Center-Spot-Your-Mirror/

I'm on your messenger i think, so if you need any more help give me a shout.

Also, one more thing. Make sure your scope is sufficiently cooled as this is also cruicial for planetary performance in a newt, especially a sealed tube like the Europa. I did a fan modification to mine and it reduced cool down time from 2 hours to a quick 20 minutes.

[Doc]

My first thought was collimation as well. Seeing no detail whatsoever does sound like a collimation problem.

Also being F4.8 you must have well corrected eyepieces. Being a zoom eyepiece I bet most of the false colour comes from this.

Do you see coma with this eyepiece. Do your stars have little comet like arms protuding from them?

[DAVPPK]

My first thought was collimation as well. Seeing no detail whatsoever does sound like a collimation problem.

Also being F4.8 you must have well corrected eyepieces. Being a zoom eyepiece I bet most of the false colour comes from this.

Do you see coma with this eyepiece. Do your stars have little comet like arms protuding from them?

When they were out of focus, yes. They did sharpen to pinpoints, though. Also, the back of my scope has only 3 tightened bolts..not sure how to collimate!! The secondary bolts work, though.

[peeceeTal2M]

are there 3 wing nuts on back of your scope? if so these are the collimation screws, thats why collimation is easy to lose, a tiny movement on one of those wingnuts is enough to throw collimation out.

[DAVPPK]

No, there aren't any

[Matthew.Blake]

Why not post a picture of the back of your scope so someone can annotate it for you.

[peeceeTal2M]

there might be a removable cap, a photo would help sort out your problem

[peeceeTal2M]

Hi Dave , you also said "the secondary bolts work" how much did you turn the bolts?? Without using a laser collimator or a cheshire you probably havent realigned the secondary mirror exactly right either.

[michigander]

When they were out of focus, yes. They did sharpen to pinpoints, though. Also, the back of my scope has only 3 tightened bolts..not sure how to collimate!! The secondary bolts work, though.

This seems like a good place to mention the the last three (used) scopes I've gotten have had all 3 adjustment screws completely tightened.

Having a 'screw loose' isn't always a bad thing!

Dana

[nitram100]

I remember when i took my scope out to the garden once and left it for 15 mins or so and when i came downstairs my brother said "I tightened those nuts on the back for you, they were a bit loose"