13 mm - 32 mm gap

[Moonlit Night]

My 32 mm plossl gives me x27 (ish) and my 13 mm gives me x67. How many of you would bisect these with an 18 mm (ish).

 

[Don Pensack]

Only if you find the 40x gap too large.

To decide on an eyepiece in between, figure out the halfway point in magnification, and divide the focal length of the scope by that magnification.  That will give you the eyepiece focal length to go for.

If your scope is 100mm or larger, I wouldn't think you would really need an in between magnification.

Edited March 8 by Don Pensack

[Moonlit Night]

Cheers Don. It is 102mm and that was kinda what I thought. Just checking in really. Thanks for your time, appreciated. 

[John]

I probably would put something in between the two but I prefer to have more options rather than less.

It might not get as much use as the 32 or the 13 though 🙄

 

Edited March 9 by John

[inedible_hulk]

I find my 18mm ES 82 useful in my 102mm  refractor. I use it a fair bit along with the 30mm UFF. Like @John says, sometimes it’s nice to have the option.

[Ricochet]

You’ve not included what I consider to be a vital piece of information, the focal ratio of your telescope, so that we can consider the question in terms of exit pupil. In my opinion the most important (DSO) eyepiece in your set is the one that produces an exit pupil between 2mm and 2.5mm with your telescope. I believe that your telescope is f/8.6 so the eyepiece that I would spend the most money on, and plan the entire eyepiece set around lies in the range 17.2-21.5mm, so in this case yes, you do need to add an 18.2mm Delite to your collection. However, in my f/6 scope the 13mm would generate an exit pupil in the 2-2.5mm range and so the 18.2mm would only be a luxury eyepiece rather than a necessary one.

[Moonlit Night]

Yes, it’s fl8.6, a Tele Vue 102 refractor. The 13mm gives me an exit pupil of 1.5 and the 32mm 3.7. Planetary and lunar observation are where my interests lie, hence the 4mm, 5mm, 7mm, 9mm spacing with the 13 mm and 32mm as fill ins for times of poor planetary position or white light solar. I plan my ocular choices based upon my personal interests, which I think is probably the way to go.

Edited March 10 by Moonlit Night
Spelling mistakes and additional information.

[mikeDnight]

I'd seriously consider the Altair 18mm UFF. It really took me by surprise because of the truly flat field and comfort it offers. The 24mm UFF is another that may be worth considering, as it will give a darker more contrasty sky background than the 32 Plossl, and from some accounts on CN delivers a more comfortable and flatter field than the 24 Panoptic, while at a fraction of the price.

[Alan White]

I would go with an 18mm as I have with a similar spread.
I have both the 18 UFF and 18 DeLite, similar but the TV wins by a small margin.

[Louis D]

I was thinking the same thing.  The Svbony 18mm UFF version, SV190, is only $81+tax here in the US.  That's way cheaper than the 18.2mm DeLite ($269+tax).  The spread in the UK is probably even wider.

[Naughty Neal]

Yes it is   Loius, 18mm Delite's  are £265/ $335 here in the UK  where as the Sv190  18mm uff can be had for £52/$66  (which I paid) in the winter /new year period  on AliExp. 

Buying via AliExp is all about timing and choosing the sales /offer periods for the real value in price.

Like wise with the SV215 at £75/$95.

 

Yet the UFF 24mm is not a bargain and the Flo priced Stellamyra 24mm uff is cheaper.

 

Edited March 21 by Naughty Neal

[Naughty Neal]

The 22mm Oberwerk in Angeleyes guise/branding  is approx. £70/$89 currently .