Hopefully my last eyepiece question.

[stephec]

I'm looking for a 1.25 plossil around 30mm for a 150mm F5 reflector, there's plenty of choice available but is there anything that stands out? 

 

As it's to go with a 7 - 21mm zoom would I better off getting a 28mm and 35mm, or should the 30mm cover everything? 

 

 

[vlaiv]

30 minutes ago, stephec said:

I'm looking for a 1.25 plossil around 30mm for a 150mm F5 reflector, there's plenty of choice available but is there anything that stands out? 

I really like my GSO 32mm plossl, but not sure if it stands out against other 32mm plossl offerings.

31 minutes ago, stephec said:

As it's to go with a 7 - 21mm zoom would I better off getting a 28mm and 35mm, or should the 30mm cover everything? 

32mm plossl is maximum in 1.25" format without loosing field of view. It has field stop of about 27mm.

Longer focal length eyepieces in 1.25" are bound to have smaller FOV - and in principle show you same amount of the sky (same field stop) - only a bit more zoomed out in a bit narrower field of view (like 40mm plossl).

There is really not much difference between 28mm and 30mm or even 32mm - and I'm not entirely sure where you found 28mm plossl at all? Usually next step down is either 26mm or 25mm (probably same FL - just labeled differently).

[Louis D]

I agree that the GSO 32mm Plossl is quite good.  Some folks rave about the Vixen NPL 30mm, but at the end of the day, it's still a Plossl at twice the price, and that will show as astigmatism at f/5 at the edge of the field.

[Elp]

The vixen 30mm NPL is great, I actually use it more than my TV 32mm plossl. The vixen does have distortion at the edges but something about using it feels better, and I can use it with glasses, the TV I can't.

[vlaiv]

2 minutes ago, Elp said:

The vixen 30mm NPL is great, I actually use it more than my TV 32mm plossl. The vixen does have distortion at the edges but something about using it feels better, and I can use it with glasses, the TV I can't.

That is quite odd.

32mm Plossl has very generous eye relief - around 22mm. I never had problems with eye relief in such way. I did have issue of having too much eye relief when I use it with Mak102 (something about amplifying secondary leads to increase in eye relief), but never not enough of it. Granted - I don't wear glasses when observing.

[Mr Spock]

I have an old Meade 4000 series 32mm Plössl. It is amazingly sharp. 

[Elp]

1 hour ago, vlaiv said:

I don't wear glasses when observing

I usually don't, but when I'm doing manual alt az without glasses I can't see stars properly via my Rigel, so constantly putting them on and taking glasses off to look through an eyepiece is awkward, so I've decided I want to keep them on and get rid of eyepieces which don't comply.

[Louis D]

1 hour ago, vlaiv said:

That is quite odd.

32mm Plossl has very generous eye relief - around 22mm. I never had problems with eye relief in such way.

Perhaps the TV eye lens is recessed a bit much?

My Orion Sirius Plossl 32mm has the eye lens recessed so much that I can only just use it with eyeglasses.  The 26mm version is recessed a similar amount, making it impossible to use with eyeglasses due to Plossl eye relief scaling with focal length.

[Louis D]

1 hour ago, Mr Spock said:

I have an old Meade 4000 series 32mm Plössl. It is amazingly sharp. 

Is it one of the old Kowa made 5 element ones?  Those are exceptional if you can find them.

[Ratlet]

My 32mm svbony sv131 plossl is the bees knees.  I use mine with a 130pds and it is generally pleasingly sharp for most of the FOV.  

I use it instead of a finder scope.  Once I get close with the Rigel I use the plossl to get the last bit to target.  It's got shed loads of eyerelief so I can leave my glasses on when I check charts against the eyepiece.  If I don't wear glasses I find my eye gets too close to the eyepiece and I start getting blackouts.

[vlaiv]

9 hours ago, Louis D said:

Perhaps the TV eye lens is recessed a bit much?

It looks like it indeed is!

They probably wanted to make eye positioning easy with this eyepiece so they artificially shortened long eye relief.