36 replies to this topic

[City Kid]

With my XT8 I found eyepieces in the 6mm-8mm range gave me the best planetary views. If I were looking for one eyepiece for high power for that scope I would go for a 7mm unless you have steady enough skies for a 5mm or 6mm.

[SteveFour86]

I'm also planning to buy an Orion XT8 and am also thinking of buying 2 accessories that would go with it: a telrad and a planetary EP (the package only has a 25mm which I guess would not be ideal for viewing planets).

Do you guys have suggestions on what eyepiece would perform well with this scope? Or would it be better to buy a 2x barlow lens now and just double the magnification of the 25mm EP provided (instead of buying a separate EP)?

My suggestion is having a 32mm, 25mm, 18mm, 14mm, 10mm, 5mm ep's with up to 60 degree fov in your ep case. Now some will suggest a barlow for cost concerns, but if you can afford it get ep's spread out nicely that are parfocal. IMO a barlow is a pain in the rump, however if you can't afford a barlow with a 32mm, 25mm, and a 10mm will cover most of what I stated before.

[ebusinesstutor]

I'm also planning to buy an Orion XT8 and am also thinking of buying 2 accessories that would go with it: a telrad and a planetary EP (the package only has a 25mm which I guess would not be ideal for viewing planets).

Do you guys have suggestions on what eyepiece would perform well with this scope? Or would it be better to buy a 2x barlow lens now and just double the magnification of the 25mm EP provided (instead of buying a separate EP)?

You might want to consider the XT8i instead of the XT8. While both will give you great views, the i version comes with some extra accessories you may end up buying anyway which make the $200 extra cost a great value.

The XT8i includes these extra items the XT8 lacks:

• A 9x50 RACI Finder (value $85)
• A 10mm plossl eyepiece and a 25mm plossl - XT8 only has 25mm (value of 10mm plossl $46)
• Intelliscope (not sold separately)

This means you only pay $69 for the Intelliscope feature that gives you push-to technology to find over 14,000 night sky objects.

I really enjoy my RACI finder and I use it with a Telrad. The combination of the two are a lot more powerful and make it easier to find objects than the simple red dot finder that comes with the XT8 even if you don't use the Intelliscope function.

[Hdjedi]

I have to second Garlands comment. The RACI and the 10mm are both valuable and the push to technology is certainly worth it esp for the fainter stuff. I have the 10i and even though I use the push 25% of the time, it really makes a difference. Get a good chair too!

[JLovell]

I'm also planning to buy an Orion XT8 and am also thinking of buying 2 accessories that would go with it: a telrad and a planetary EP (the package only has a 25mm which I guess would not be ideal for viewing planets).

Do you guys have suggestions on what eyepiece would perform well with this scope? Or would it be better to buy a 2x barlow lens now and just double the magnification of the 25mm EP provided (instead of buying a separate EP)?

I got a couple of Burgess/TMB planetaries, and will probably get another, slightly higher power for when seeing allows. Astronomics has them for less than $60 and a little discount for entering your user id from here. They seem really good for the price. I just ordered a Meade 4000 QX 2" 36mm from adorama.com for $50 and free shipping. I don't know how long that price will last. I've been told that eyepiece works well in our scopes for DSO, although I haven't looked through one. I saw the low price and just took a chance.

[OneEyedLeela]

With the 5mm TMB EP, is the view still sharp? Or is the 9mm TMB more useful (with regard to image resolution)?

[JLovell]

I can see a lot more on Mars (the only planet I've looked at since I got them.... it's been the only one out when I have the time to take the scope out. Other planets might have different results. Mars is hard to see well because it is so small compared to Jupiter and Saturn.) with the 5 when everything is still enough to use it. Mars is still pretty small with the 9, although I can faintly make out the ice caps and some darker areas with it. It is quite a bit bigger with the 5, although frequently a bit blurry at best focus. I've seen it really sharp in the 5 a couple of times when I got the scope really well cooled and had good seeing, at least in light polluted close in Atlanta burbs. The 9 is always clearer unless everything is just right in the sky. Maybe a 7mm or so would be a nice one to try... bigger views, but not as blurry as the 5? I still want to get a slightly higher power one to see if it'll look good when everything lets the 5 gets sharp. One nice thing about the TMB's is that there are a LOT of FL's for them in a relatively small range, and they are relatively cheap. I may just go ahead and get the 7 too when I get my tax return back.

[JLovell]

I like the TMB's because they are almost as sharp and contrasty as plossls, almost as cheap, and a lot easier to look through at the short FL's. My 6.4mm plossl has a TINY eye lens and eye relief is so short, it is almost like I have to touch my eye to it to see. All the TMB's have large eye lenses, enough eye relief that I think glasses wearers (I'm not one, so I don't know that for sure) can look through them, and have just enough more FOV to make tracking a little easier.

[City Kid]

Whenever I use a 9mm eyepiece in my XT8 the view is almost always sharp. When I use a 7mm (actually 6.7) the view is sharp more than half of the time and the detail seen is much better than in a 9mm when the atmosphere steadies. A 5mm eyepiece in my XT8 shows more detail than either a 9mm or a 7mm but the atmosphere only allows me to use my 5mm maybe 25% of the time. I do all of my planetary viewing from my backyard and in all directions I am viewing over roof tops so it's rare that I get a truely steady night. For me a 7mm is the best compromise between the magnification I want to use and the magnification the atmosphere will allow me to use. In a perfect world it would be nice to own a 9mm, 8mm, 7mm, 6mm, and a 5mm. that way you would own whatever works best that particular night. However, if you are only starting with one I wouldn't go any shorter than 7mm unless your skies are steady most of the time. If you will only own one high power eyepiece you will probably want one you can use most every night.

[TMK]

I'm also planning to buy an Orion XT8 and am also thinking of buying 2 accessories that would go with it: a telrad and a planetary EP (the package only has a 25mm which I guess would not be ideal for viewing planets).

Do you guys have suggestions on what eyepiece would perform well with this scope? Or would it be better to buy a 2x barlow lens now and just double the magnification of the 25mm EP provided (instead of buying a separate EP)?

Sounds like a good plan, however dont underestimate the importance of an observing chair. Keep that high on your list.
I would get the barlow first though.

[City Kid]

I definitely have to agree on the importance of an observing chair. Not being comfortable will hinder observing as much or more than bad seeing.

[JLovell]

I put a link for making a chair for about $20 in the frugal astronomer thread.

I'd also like to second the idea that about a 7mm planetary eyepiece is probably the ideal one to have in these scopes if you only get one. The more I think about it, I'm going to get that one first, then get a 3 or 4 later.