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View Full Version here: : The lowly Plossl still holds its own


MortonH
30-09-2014, 12:13 AM
On Sunday night I got out to a dark sky for the first time in ages. I'd acquired several new eyepieces since the last time and was eager to try them out.

The big surprise was the performance of the Tele Vue Plossl 25mm. The views were so crisp and natural. The only thing it gave up against my Panoptic, Delos and XF eyepieces was field of view. And the 50º didn't feel too restrictive either.

I feel a 20mm Plossl may be in my future...

Kunama
30-09-2014, 07:04 AM
I find I actually prefer the narrow field of view for my observing, I can concentrate better on my target (usually planets, lunar features or Sol) with the narrower FOV rather than scanning about.

I have switched back to Vixen LVs.

MortonH
30-09-2014, 12:53 PM
Before I got the Plossl and XF eyepieces I was used to at least 68°, so it's a little strange to have a narrower field of view. But as long as the object is framed properly it concentrates the mind on the object without being distracted by its surroundings. I still like the wider views to provide context, but for seeing more detail in the object itself, switching to an eyepiece with narrower field but better throughput works well.

The_bluester
30-09-2014, 01:59 PM
I have found a need for both wide and narrower fields. For most DSO's I find the widefield EPs much nicer to use as the SCT does tend to limit your true field, taking a wider ture field and spreading it over a larger apparent field I find nice and immersive.

Move over to planetary however and the shorter focal length Plossls I have take over without a doubt.

209herschel
19-10-2014, 06:10 PM
I'm happy to hear the positive comments on using the plossl. I'd set myself to get 2 or 3 Explore Scientific or perhaps a Panoptic if I got a good second hand one, but I've been using the GSO plossls that came with my 10" dob and I've been pleasantly surprised. I especially enjoyed the 25mm plossl. It's made me reconsider. I'm now thinking of getting the TV 11mm plossl (planetary/moon - with 2x barlow), and perhaps the TV 20mm plossl.

I'd be keen to hear anyone's thoughts on a TV 11mm barlowed v an ortho 6mm for planet/lunar viewing. My scope is undriven.

Cheers.

MortonH
19-10-2014, 07:03 PM
Another option is the Pentax XF 8.5mm. Mine shows a small amount of field curvature on its own but this disappears when used with a Barlow. So for the next Jupiter opposition I'm hoping this will be a good combination in my scopes. The XF's 60º AFOV will be welcome over the Plossl's 50º since my scopes are also undriven. The XF also has 18mm of eye relief.

simmo
19-10-2014, 10:52 PM
The ortho I use in a SW 10" and I find it good to use. Jupiter will slip out of it quickly but for the other planets it is not too bad. I have only looked at Mars, Jupiter, Saturn.

Will definitely hold its own against the TV I would think.

The only thing that holds it back maybe 60% of the time is the atmosphere.

I would agree with you Morton about concentrating on the object and narrow field of view. I only use orthos for all viewing and chose them for that characteristic. I would think that not having extra light sources like bright stars interfering when searching for extra detail is a bonus too. Good on you for adding a new patch on your observing sleeve :) and welcome to the S.F.O.V. Club.

Regulus
19-10-2014, 11:16 PM
I have the 9/15/20 and 32 Celestron SPlossls and am very happy with the them. Field of view suits and so upgrading will be to TV Plossls with 1, maybe 2, wide field 25 & 30+mm for the objects that are better suited to that sort of FOV.
The only reason for upgrading is the expectation of better contrast and perhaps better colour repro.
Trev

MortonH
20-10-2014, 01:34 AM
I have a Smart Astronomy 20mm Plossl ready for collection at the Post Office. I'll be interested to see how it compares to my 19mm Panoptic for contrast and transmission.

Still hoping to find a used Tele Vue or Parks 20mm, though.