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Re: How many eyepieces should we have?

Posted: Wed Sep 29, 2021 6:44 pm
by Jones
Go minimalist, low power eyepiece, zoom, Barlow, prism diagonal.
Zoom is a Nikon 7-21mm, add 2.5x Barlow it becomes 2.8-8.4mm.

Zoom is available from Japanese discounters on Ebay for around $250.
Much better than any astronomy made zoom. Optical quality as good as XW-Delos.
Field of view approx. 50 -65 degrees.

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Re: How many eyepieces should we have?

Posted: Wed Sep 29, 2021 7:35 pm
by Bigzmey
Jones wrote: Wed Sep 29, 2021 6:44 pm Go minimalist, low power eyepiece, zoom, Barlow, prism diagonal.
Zoom is a Nikon 7-21mm, add 2.5x Barlow it becomes 2.8-8.4mm.

Zoom is available from Japanese discounters on Ebay for around $250.
Much better than any astronomy made zoom. Optical quality as good as XW-Delos.
Field of view approx. 50 -65 degrees.

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Utility of a good zoom EP is hard to overlook. I have my travel observing set configured similar to yours with a zoom and a barlow (both Baader in my case). The weakness of this approach however is the lack of low power wide field views. Leaving optical quality of zoom vs fixed FL discussion aside, even simple 32mm Plossl will provide 52% wider TFV compared to your zoom and Pentax XW 40mm will provide 2.6x wider TFV.

Re: How many eyepieces should we have?

Posted: Fri Oct 01, 2021 5:08 am
by Jones
I dont spend a lot of time at low power. The 24mm gives about 45x in my 10", almost enough field to frame the double cluster in Perseus. Move over to Casseopia and all those little star clusters you need at least 100x to expand them to 1/2 your field of view. The zoom at 12mm is up to it's full field of 65 degrees and everything looks real nice. If you are pressed for money a zoom makes alot of sense. The spotting scope eyepieces give you optical quality for the price of 1 premium astro eyepiece.

I wrote a review of this lense when I first got it, it's a few pages back in this section.

Re: How many eyepieces should we have?

Posted: Fri Oct 01, 2021 12:34 pm
by Piero
I agree that the number depends on the scope. I have a set per scope, plus some "jollies"..

- 16" f4: 30 APM (jolly), 24 Pan, 12.5 Docter, 8 Delos, 6 Delos, VIP barlow typically set to 1.82x and used with Delos
- 4" Tak: 30 APM, Zeiss zoom (these two use 2" barrel and are used on DSOs); 9 Nagler, 5 ortho, 3.4-2 HR (planets and double stars)
- TV-60: 24 Pan, 9 Nagler, 3.4 HR, 2.4 HR (jolly)
- 12" f6: 30 APM, Zeiss zoom +/- VIP barlow

I am considering to replace the 5 ortho with a 5 Nagler. Although the ortho works very well, it is too short ergonomically. I need to be careful not to hit my face with the corner of my 2" diagonal.. With my 1.25" TV everbrite diagonal, it is even worse, because my nose hits the diagonal screw, which is installed to the right, and I observe with my left eye. :Astronomer1:
For these reasons, I've been pondering about a 5mm Delite too. Although this would work well, I don't particularly fancy its super tall appearance, compared to the Nagler and the HRs.. In addition, the larger AFOV of the 5mm Nagler means that this eyepiece could also be used as a jolly with the 16" f4. It would also fit in the TV-60 bag if I want a "DSO-only" set (24P, 9N, 5N) with that telescope. On the other hand, the quality of the Delites is reported to match the Delos and this eyepiece would mainly used with the Tak.. :Think: :Think:

You see, this is an example of why people have a lot of eyepieces....! Rumination over rumination about what the best is for your equipment! :flame: :lol:

Re: How many eyepieces should we have?

Posted: Fri Oct 01, 2021 5:29 pm
by Lady Fraktor
You should have enough to fill a medium sized barrow. ;)

It is all about variety!