Eyepiece gap and filters

[darthvader]

Ok so I havent spent any money for at least a month on astro equipment....

Been looking at a few doubles in the last few weeks and feel that I need another EP at around 10-12mm to split some of the closer ones. The stock 10mm EP aint great so any recommendations?

Also, I want to get a filter for the moon and a filter for nebulae (was looking at the dumbell nebula tonight)

Is it possible to get a good filter set for most requirements or is it best to buy individual filters?

Thanks

[gbarnett]

I like the 11mm ES82 in my dob and am really glad I bought it. Another option would be to get a Baader Classic Q 2.25x barlow for approx £45. The lens cell on it's own gives 1.3x mag. When used with your 16mm MV eyepiece the 1.3x mag will give you approx. 12mm and when used at 2.25x with the 16mm MV will give approx 7mm which will fit in nicely between your WO 6mm SPL and 16mm with 2 x X-cel barlow at 8mm. One warning though is that the 16mm MV will need 14mm clearance within the barrel for the 1.3x element to fit.

I'll leave the filter question to the experts as I've been pondering which UHC filter to buy (not an easy decision!   ) but with your eyepieces you may want to look at 2" filters and get a 1.25 - 2" adaptor and extension ring so that you can use which ever nebulae filters you get with both 1.25" & 2" eyepieces.

Graham.

[Dave In Vermont]

I am a certifiable Filter-Nut. I have more than I recall. So I know a bit about them. And if I may make a suggestion? Do not buy a set of coloured filters offered by many companies. You likely won't use them. Every amateur-astronomer seems to have these - growing mold.

I suggest you first find out what filters will help you to see the sort of objects you like better. Here is an excellent listing of many stellar entities and what works best for each:

http://www.prairieastronomyclub.org/resources/by-dave-knisely/filter-performance-comparisons-for-some-common-nebulae/

From there you can start looking into reviews of the different ones available from different manufactures such as Astronomik, Baader, Lumicon, etc. As for a Moon filter, I suggest a variable polarizing-filter set. These come as 2 separate cells that are rotated to each other to vary the dimming from 40% light throughput, down to 3%. A standard 'Moon Filter' that comes with many new telescope packages is a stock 13%. The variable ones leave that in the weeds.

Clear & Dark Skies,

Dave

[jetstream]

Filters: UHC or OIII

Brands: Astronomik or Lumicon

10mm: Baader Classic Ortho

IMHO

[Ruud]

Hi, I recently bought a 12 and an 8mm Delos.

Can't get over how good they are. I am financing the 8mm by eating macaroni for the next six months.

[jetstream]

Yes they are good, I have the 8mm and 6mm. It would be interesting to test the 10mm Baader Classic ortho against a 10E, and 10D, on DSO that is. No doubt the ortho will split stars as good as the Delos.

[Dave In Vermont]

Yes they are good, I have the 8mm and 6mm. It would be interesting to test the 10mm Baader Classic ortho against a 10E, and 10D, on DSO that is. No doubt the ortho will split stars as good as the Delos.

Ah! Another orthoscopic EP fan! For those subjects that benefit from the best resolution of fine details, the ortho has withstood the test-of-time. Not expensive - by today's standards - and needing one to get close-in to the outer lens, the view is it's own reward.

Clear & Sharp Skies,

Dave

[darthvader]

Hi, I recently bought a 12 and an 8mm Delos.

Can't get over how good they are. I am financing the 8mm by eating macaroni for the next six months.

that's what i call dedication !

thanks for all the recommendations/info people

I reckon i'm gonna go for the variable polarizing moon filter for starters - nice price too for the xmas list...

is the FLO one below ok anyone?

http://www.firstlightoptics.com/moon-neutral-density-filters/variable-polarizing-moon-filter.html

I am really impressed with the two existing Explore Scientific EPs I have so I'm tempted by the ES 11mm which looks a good price:

http://www.telescopehouse.com/acatalog/Explore_Scientific_11_mm_82__water_proofed.html

The Delos is mighty expensive:

http://www.telescopehouse.com/acatalog/TeleVue-12.0mm-Delos-Eyepiece-1.25-.html

is it worth the extra ? it's almost double the price ! (the 10mm is around the same price so I would probably go for the 10mm if i bought one of these)

I could afford the Delos but I like value for money   so it would have to be well worth the extra....

..now to look into those Astronomik or Lumicon UHC filters you guys recommended....

[John]

I don't think there will be a signficant difference between the Delos and the ES equivilent - it will be slight despite the large price differential. This does not seem to stop quite a lot of folks wanting the Tele Vue products though and Pentax too, which are in the same price / quality niche,

I owned a 10mm Delos for a few weeks to see what they are like and I found it a really nice eyepiece to use. I can't wean myself off my taste for hyper-wide views though so I've sold it on and I'll stick with my Ethoi, which cost even more of course !

[Ruud]

I read a thorough, mostly objective review of the Delos, Ethos , Pentax XW, Nikon NAV10-SW, Tak 10-UW and Celestron Luminous, compared to each other on an optical bench.

The measured values are:

• CA at the centre and at the edge of the field
• Wavefront error on an  f/3.5 and an f/7 telescope,  in the green and red, on-axis and off-axis
• Colour (warm, neutral, cool, etc.)
• Apparent field of view
• Transmission
• Viewing Comfort
• Ergonomics

Out of 20 points, Delos got 16 and Ethos 15 points, even though the Ethos got more points for the apparent field of view. These two were  the best in the test. The Takahashi and the Celestron scored worst: 10.5 and 8 points respectively.

You need to zoom in deeply on the pdf to see the differences in the CA, and please don't mistake the "ring of fire" at the edge of the Delos and Ethos for CA. 

Here is the review: http://www.cieletespace.fr/files/InstrumentTest/201306__6_oculaires_10mm.pdf

Yes, it's in French, but if you scroll down till you see this bit...

... and refer to the list of measured values above you should be able to understand the table.

[Moonshane]

another option is a used Televue Radian if you can find one. either a 12mm or 10mm would be £100 approx. OK it's 'only' 60 degree field but an excellent eyepiece.

for me the best value for money comes from used Televue Plossls and at about £50 used the 11mm is a peach.