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What short focal length EP for a frac?


dannybgoode

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Played with the TMB 105mm LZOS last night (650mm FL) it very easily managed my 4.9mm - crystal clear viewing and it’s obvious that the scope will take more magnification. 

I think a nice 3mm would be a good match but there’s so many to choose from ranging from £50-£300+. 

Budget is flexible - I just want a good one that will match the scope well. Any thoughts?

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6 minutes ago, Stu said:

I would say either a Televue Delite, or how about the Vixen HR Planetary 3.4mm or even 2.4mm? They have near legendary status and I'm sure the scope will cope. 

Thanks for the thoughts.

I was looking at the Vixen’s and contemplated the 2.4. 270x magnification though may be the reserve of nights of better seeing?

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I use the Tele Vue Nagler 4mm-2mm zoom a lot more than I thought I would with my refractors and even with my 12 inch dobsonian. They are superb for a zoom (very close to specialised short FL eyepieces in performance) and that instant variability is very handy when playing with high and very high magnifications. 50 degree AFoV and 10mm of eye relief might not suit everybody though but the eyepiece is very compact.

My other very high power options are the Pentax XW 3.5mm or the 21.5mm-7.2mm zoom plus Baader 2.25x barlow (gives a very useful 9.55mm - 3.2mm zoom).

All these have given me great results (eg: Split Sirius, E & F Trapezium, moons around Neptune & Uranus etc, etc) in my refractors so I don't tend to feel the need for more specialised high power eyepieces such as the Vixen HD's though those are clearly excellent alternative options as would be a 3mm Delite.

Your scope should be able to handle 300x and even more under excellent conditions (my Tak 100 and Skywatcher ED120 can and do) so having an eyepiece to exploit that does make sense.

 

 

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Assisted by helpful advice from members of this forum, I purchased the 3.4 Vixen HR and the Tak TOE 4.0 mm (I’d sold some stuff so the purchases were guilt free ?).  Both, imv, are absolutely fantastic eyepieces!  I even tried Barlowing the 3.4 on the Moon with a x2 Powermate just to see what happened. Seeing and, with the .24mm exit pupil, floaters, of course, came into it but in terms of performance, comfort and useability the eyepiece couldn’t be faulted. This was with the 980mm fl TEC 140. Last night I tried both of them in my 6in f6 Newt (which has excellent optics) giving about x270 and x230 - magnifications I’d rarely consider using with that scope. Same conclusion. Fantastic eyepieces! I’d go so far as to say that, with certain targets and applications, they’ve opened up for me a whole new way of observing.

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I would go for one of the Nagler Zooms and echo Alan’s & John’s comments above..... I have recently acquired the 2-4 to accompany the 3-6 and they are simply wonderful eyepieces ? They are also very compact and unobtrusive. 

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On 11/02/2019 at 20:56, dannybgoode said:

Thanks all for your thoughts. Will keep an eye out for a Nagler 2-4mm. And the Tak TOE is looking a decent contender too. 

Will report back once I’ve decided :)  

Is the scope driven or undriven?

If undriven, widefield will help in locating and nudging. I have 3.5mm Nag T6 for that. If driven, there is a lot of purists' choice to chose from, mind the eye relief, though, and try not to go under 0.5mm exit pupil.

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On 11/02/2019 at 07:32, dannybgoode said:

I was looking at the Vixen’s and contemplated the 2.4. 270x magnification though may be the reserve of nights of better seeing?

I think that would be stretching the capacity of the scope a bit and would not get used very often.

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I have now bought the Vixen HR 2.4mm and am very pleased with it. Have given it a whirl on lunar obs and the night was far from perfect - lots of atmospheric disturbance - but it still performed admirably. 

Unfortunately I can see the 3.6mm being a necessity also :)  

The optics of the TMB are essentially perfect and I think I’d even be tempted to try a 1.6mm. Ok now that really might be pushing my luck but it would be interesting to at least give it a go. 

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1 hour ago, dannybgoode said:

I have now bought the Vixen HR 2.4mm and am very pleased with it. Have given it a whirl on lunar obs and the night was far from perfect - lots of atmospheric disturbance - but it still performed admirably. 

Unfortunately I can see the 3.6mm being a necessity also :)  

The optics of the TMB are essentially perfect and I think I’d even be tempted to try a 1.6mm. Ok now that really might be pushing my luck but it would be interesting to at least give it a go. 

Boy, everyone is raving about Vixens...stay me away from temptation.

3.5 or 3.6 would give you 185x, so there is a pretty big jump from that to 270x on 2.4. Delite 3mm instead (or in addition), for 215x?

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2 hours ago, BGazing said:

Boy, everyone is raving about Vixens...stay me away from temptation.

3.5 or 3.6 would give you 185x, so there is a pretty big jump from that to 270x on 2.4. Delite 3mm instead (or in addition), for 215x?

Resistance is futile ?

There is the Vixen HR 3.4 mm

Or the Tele Vue 3 to 6 mm zoom is a lovely, versatile, eyepiece

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  • 3 weeks later...

It is important to be realistic when it comes to magnification and targets. My floaters vary, and even under super seeing 212x in FC100 DF was exposing some of them on the Moon. I did not feel like I wanted more magnification, I wanted less floaters. :)

I have now pulled a trigger on a second-hand Delite 4mm which will come in May, less power but a stopgap between 148x (Nag 5mm) and 212x of Nag 3.5. 4mm is 185x it may be just right for some nights and some targets, and AzGTi will deal with the narrower FoV. 

So for the OP, I guess something like 3.5mm T6 or a similarly powered Ep might be just what he needs.

 

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4 hours ago, BGazing said:

It is important to be realistic when it comes to magnification and targets. My floaters vary, and even under super seeing 212x in FC100 DF was exposing some of them on the Moon. I did not feel like I wanted more magnification, I wanted less floaters. :)

A great excuse to increase your aperture to decrease floater visibility. ?

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