eyepiece and barlow

[jacob5800]

hi just bought a sky-watcher 150/750 6inche diameter telescope  two eyepieces came with it  super25mm  and a super10mm basic eyepiece,  bought  one two inches barlow luminos  2x.5  and one two inches eyepiece  Antares 31mm  anybody ever tried those eyepiece and barlow.  was that a good choice  thanks for reply to this

[damnut]

Hi There,

The luminos barlow is a great piece of kit. I have not had the Antares 31mm but do have the Antares 34mm 70 deg. These are made in Canada & I found the 34mm to be a very good ep.The Antares will provide you with 24X.

[ronin]

A lot will depend on what it is that you are intending to look at. One other factor is the 2 supplied eyepieces they are likely to be not very good I would expect Huygens or Ramsdens.

I have tended to simply ignore the suppiled items when suggesting eyepieces, the idea you can use the supplied or buy newer options depending.

My "rule" is one at the f number, one a bit longer, then a wide and a medium.

In yours that is 5mm, a 7mm or 8mm, something up at 30mm then a medium at around 18mm.

How you achieve that  is up to you the 31mm and a 2x barlow will give 15-16mm so wide and medium, the shorter end is really 2 eyepieces.

Better give a bit more information on the barlow as 2x.5 is not a recognised format, do you means 2.5x ?

If so then one problem is that as the barlow power goes up the usable eyepieces goes down, a 5x balow and a 15mm EP is too much, even a 20mm EP with one is questionable.

Antares tends to be fairly good, think they are made in BC so you could fly over and complain in person if you like. I have 3 or 4 of their W70 eyepieces.

Decide what it is that you intend to view as some are of reasonable size, M42, M45, so going to high magnification and narrow field of view is pointless. 100x on M45 and M42 will put only half of either in view.

Personally I prefer eyepieces only, no barlow, and owing to the selection now not sure what advantage 2" eyepieces have in realistic terms. An Antares 25mm W70 will give 30x and a field of 2.3 degrees in your scope. Of the familiar objects I can only drag M31 into mind that will not fit in.

[jacob5800]

A lot will depend on what it is that you are intending to look at. One other factor is the 2 supplied eyepieces they are likely to be not very good I would expect Huygens or Ramsdens.

I have tended to simply ignore the suppiled items when suggesting eyepieces, the idea you can use the supplied or buy newer options depending.

My "rule" is one at the f number, one a bit longer, then a wide and a medium.

In yours that is 5mm, a 7mm or 8mm, something up at 30mm then a medium at around 18mm.

How you achieve that  is up to you the 31mm and a 2x barlow will give 15-16mm so wide and medium, the shorter end is really 2 eyepieces.

Better give a bit more information on the barlow as 2x.5 is not a recognised format, do you means 2.5x ?

If so then one problem is that as the barlow power goes up the usable eyepieces goes down, a 5x balow and a 15mm EP is too much, even a 20mm EP with one is questionable.

Antares tends to be fairly good, think they are made in BC so you could fly over and complain in person if you like. I have 3 or 4 of their W70 eyepieces.

Decide what it is that you intend to view as some are of reasonable size, M42, M45, so going to high magnification and narrow field of view is pointless. 100x on M45 and M42 will put only half of either in view.

Personally I prefer eyepieces only, no barlow, and owing to the selection now not sure what advantage 2" eyepieces have in realistic terms. An Antares 25mm W70 will give 30x and a field of 2.3 degrees in your scope. Of the familiar objects I can only drag M31 into mind that will not fit in.

I mean 2.5x sorry made a mistake

[Roy Challen]

"not very good I would expect Huygens or Ramsdens."

I don't think that's entirely correct Ronin. Being achromatic eyepieces, they will only work well in an achromatic telescope. So, limited -yes, but poor- not necessarily. My Zeiss huygens is incredible in my f/16.4 achro frac. I have another huygens from a less well known maker that also produces excellent results.