Celestron x-cel lx 7mm

[infinityrko]

Tried this new Celestron x-cel lx 7mm eyepiece last night and i found it was way out of focus all i could see is the moon light and not the moon tried focusing it in wit the focusing on my scope but still to no luck.  

[Dave In Vermont]

Welcome to SGL - good to have you aboard!

It would help if you told us what sort of telescope you're using. And then go over what you did point-by-point. Then we very likely can get you going.

Is this a new telescope? I know the eyepiece is, I ask as if you have been using it awhile, it would help to know what other eyepieces you have used and how they are working for you.

Clear skies,

Dave

[infinityrko]

hi dave just got my new celestron cgem 925 sct telescope 

was just using the 25mm eyepiece that came with it and had good results then tried the x-cel lx 7mm eyepiece and could only see a bight light with no detail 

[Dave In Vermont]

Okay -

So a Celestron 9.25 F/10 with a focal-point of 2350mm. So that gives us 335.71X. That's some pretty good magnification. How was the 'seeing'? Did you have any problems using the 25mm EP that came with your scope? That would give you 94X. No problem getting that to a sharp focus? When you tried to rack the focuser to get the 7mm into focus, did it seem to run out of space? As in it was getting to what seemed a good focus and then you seem to have run out of enough travel?

I'm trying to determine how well you are aquainted with using a telescope. It sounds as though you may be rather new to all this. Not a problem, mind you - it just tells me how best to figure out how to approach the problems with you here. You shouldn't be having any issues that I can see yet. But you've certainly gotten me interested to work on a solution. Don't worry, we can get this sorted. I'm glad that your 25mm is working fine. That means your scope is mechanically sound. And you were able to get a good look at the total lunar eclipse! So you didn't miss out. I didn't go over 50X myself. We had excellent 'seeing' over here.

I'll be watching -

Dave

[infinityrko]

the 25mm was good then the 7mm lx was a big let down... all new to this 

[John]

Hi and welcome to the forum

300x is a heck of a lot of magnfication to use on a full moon. The surface would just appear rather featureless and washed out because it's under direct sunlight (until the eclipse started that is !).

The best time to view the moon is when it's going though it's phases and then there will be plenty of contrast and shadow along the boundary between the illuminated and dark hemispheres.

With an SCT you also need to allow it too cool down before using high magnifications - if you had recently bought the scope outside this might have added to the washed out appearance of the lunar surface.

[sungrazer]

Hi Infinity and welcome!

I, like you, am a Celestron 925 user with a collection of X-Cel LX EPs.  The focus knob can be quite tricky to "fine tune", especially under such high magnifications and where, as other members have noted, seeing may not be so good.  Personally I use a lightweight (plastic) ring spanner over the knob to allow for fine adjustments to the focus.  I can tell you that the X-Cel is nowhere near parfocal with the stock EP's supplied with the scope.  This means a fair amount of focus travel is required when switching between X-Cel/non X-Cel EP's (in my case over 1 full turn is needed).

In my experience, patience and a methodical approach will get you there, and it only gets easier.

Clear skies!

Chris

[infinityrko]

Hi Infinity and welcome!

I, like you, am a Celestron 925 user with a collection of X-Cel LX EPs.  The focus knob can be quite tricky to "fine tune", especially under such high magnifications and where, as other members have noted, seeing may not be so good.  Personally I use a lightweight (plastic) ring spanner over the knob to allow for fine adjustments to the focus.  I can tell you that the X-Cel is nowhere near parfocal with the stock EP's supplied with the scope.  This means a fair amount of focus travel is required when switching between X-Cel/non X-Cel EP's (in my case over 1 full turn is needed).

In my experience, patience and a methodical approach will get you there, and it only gets easier.

Clear skies!

Chris

ok so it to look at far away objects rather than the moon etc

[bingevader]

Not quite.

As people have already said, a lot depends on the seeing conditions and the brightness of the object.

Unfortunately, as you use shorter and shorter focal length eye pieces, you also dim the object you are trying to view.

There are plenty of very far away objects that would be just too dim to see clearly through a 7mm eye piece.

That's why people tend to say that as a general rule, the shorter focal length eyepieces are best on  brighter objects.

You problem, if the 'scope is focussed correctly, is the opposite, in that the moon is just too bright when full to observe clearly.

On a good day, with the moon in relief, and well focussed, in your 'scope 335x magnification should be wonderful.