Got a NexStar 6SE for Xmas - Eyepiece and clarity issues

[Seanace1]

Hi All,

This Christmas I recieved a NexStar 6SE Schmitt Cassegrain scope :headbang:and am hoping to get some interesting astro-photography pictures with my Rebel T2i. I have done some reading and realize this is no "for dummies" notion, but had a few newbie questions I was hoping someone could address that I cant seem to figure out on my own...

The scope came with a 25mm eyepiece and I was able to easily begin using it. I also got a tele-xtender, t ring and an xcel 5mm eyepiece. Little did I know the Xcel eyepiece wont fit inside the tele-xtender, however, camera aside, for some reason using the 5mm eyepiece everything is extremely blurry. The 25mm eyepiece is a bit clearer but is also somewhat blurry. Per the instructions I blurred a star in focus and the "halo rings" seem symmetrical which would seem that collineation is ok (is that correct?). Are things just blurry!?

In regards to pictures of planets and the moon, I know the ALT AZ mount wont work for tracking, but can anyone suggest basic ISO, AV or TV settings as a place to start? Random guess: 800 ISO, 1.5 sec exposure, auto aperture?

Thanks so much!

Sean

[Demonperformer]

Sean

I have a 6SE, and here are a few tips from my procedure:

For the moon, I use ISO 100 and between 1/10s (for a thin crescent) and 1/250s (when near full).

Aperture will always be f/10 (unless you use a barlow lens/reducer lens).

You can take planet images with a DSLR, but most people get a webcam and get maybe 1000/2000 frames on an avi and stack the best ones using registax. The image scale is better and the results are quite presentable.

You can also take DSO images with your DSLR, as long as the object is compact enough. depending on how well you align the scope you should be able to get 30s subs easily.

As you say, it is not for the faint-hearted, and there is tons and tons to learn, but simple shots of the moon is a good place to start.

HTH

[Peter Drew]

Hello Sean, welcome to SGL. The 5mm eyepiece will give 150X magnification with your scope, this is towards the higher end of its potential, a blurry image at this power is likely to be because the scope has not reached thermal equilibrim, the object in view is low down or the general seeing is poor. Your description of the out of focus star suggests that the collimation is at least OK. I don't think eyepieces are intended to fit into the tele-extender. You will be able to photograph the Moon and planets with the alt-az tracking, at 800 ISO you will need only about 1/25 second exposure, better to use 200 ISO. Fortunately, with a DSLR you can experiment at will.

[smudgeball]

Hi Sean

Welcome to SGL.

Great to see another 6SE owner

Pretty much ditto the two replies you've already had.

You'll learn to ignore the lure of magnification.

If your scope hasn't cooled properly you will get a hazy image.

Remember that if your scope is looking over rooftops then there will be heat rising and that can cause the image to be fuzzy.

Whatever the imperfections in the view, the more you up the magnification the more those imperfections are ALSO magnified.

You'll see comments on here about "good seeing" and that's the real trick to removing some of the things you've mentioned.

You'll get there.

Have fun and enjoy the 6SE....a great scope

(don't let those pesky dob owners tell you otherwise )

Regards

Neil

[Demonperformer]

Sorry to have to contradict Peter, but a 5mm e/p on the 6SE (1500mm focal length) gives 300x magnification - although I agree you need good conditions to stand that magnification.

[Grunthos]

The 25mm eyepiece is a bit clearer but is also somewhat blurry.

Are things just blurry!?

Just a thought.

Was your scope starting to dew up? Do you have a dew shield or alternatives? SCT scopes are notorious for dewing up...

[Seanace1]

I actually had not considered the temperature variation... I took the scope out of the 75 degree house to a 30 degree yard and began viewing in about twenty minutes.. At the moment jupiter was above my house very high in the sky and i am only about 20 miles outside of baltimore. Im going to head out west and see if I can find some "good seeing".. Thanks for all the replies. In regards to the extender it takes the omni, plossls, I ordered a 9mm and a 4mm, and have the 25mm which came with..

[LukeSkywatcher]

I just bought an 8SE which came with a 25mm E-Lux. The FOV on the EP is 50 degrees so i will keep it and try it. It may be better then a couple of other 25mm i have quality wise.

[E621Keith]

I have a 6SE. I usually give it at least an hour to cool before using it. The view shouldn't be blurry with the 25mm. Even with small amount of dew, it should still be sharp. However, if you are taking the scope from a warm house to a sub-zero garden then the thermal current can really degrade the image.

Like DP said, 5mm is pushing the scope and you will need exceptional seeing to use it at 300x. I am surprise it won't fit in the TeleXtender, assuming it's the Meade model, because both should be using the 1.25" standard. However, if you use a 2x TeleXtender with a 5mm on the 6SE, it will give you 600x magnification, which is beyond the seeing limit in most location and the limit of the scope. The result will be a blur.