isn't switching between 1.25/2 inch eps annoying?

[Moonshane]

it's the adapter that reduces the focuser tube from 2" to 1.25". it's usually threaded for filters. like the one in the middle of this focuser First Light Optics - Dual-speed Crayford focuser for Skywatcher 190MN

[rwilkey]

The star diagonal is usually threaded for filters, so it will not matter what size ep you use, so a 2" diagonal will serve all....

[Macavity]

I think it ironic that (quite a few?) common, mid-range, 32mm, "70 deg" - TWO inch eyepieces, yield little extra TRUE field of view (experimentally!) than a good, wide, 1.25" eyepiece. But frankly, the latter aren't common. Not convinced all this "chopping and changing" achieves a lot, but a 2-incher always looks more impressive?

But then, I don't own that many quality 1.25" eyepieces either. <G> Seriously though, I sense, to REALLY exploit two inch format, one might have to move to "better" eyepieces, wider (35mm... 40mm...) field-stops etc. But then, many a telescope won't work with those. At some stage, I HOPE to buy (afford!) a "compromise" Pan 35 (and a Pan 24?) and cease the "internal debate"...

[rwilkey]

My advice is not to go too far down the focal legnth road, I find 2" 32mm perfectly adequate, but it is also best to stay in the higher numbers for wide-field, although I have just purchased a 7mm 82* Ax, I like to experiment I have to admit, but it can also be expensive, I love my 1.25"s as well, I use both between two scopes.

[John]

I think it ironic that (quite a few?) common, mid-range, 32mm, "70 deg" - TWO inch eyepieces, yield little extra TRUE field of view (experimentally!) than a good, wide, 1.25" eyepiece. But frankly, the latter aren't common....

I can remember when 32mm Erfle eyepieces in the 1.25" fitting were advertised as offering a 65 degree apparent field of view. I bought a used one once and measured the field stop diameter - exactly the same as a 32mm plossl, which I should have guessed if I'd known back then about the limitations of the 1.25" barrel

As is often said, the number of astro objects that need a true field of view wider than 1 degree is pretty small but that does not seem to have dented the appetite one bit for wide, ultra-wide and mega-wide fields of view. The other benefits such as sensible exit pupils with fast scopes and darkened background sky are an atrraction as well of course.

[rwilkey]

John, I totally agree with you, so you will not be rushing out to get the new ES 120* at $1000 then?

[Macavity]

I might've settled for an Ethos 17mm - And "be blowed" with the rest?

But it might be a bit short on eye-relief, AND...

[rwilkey]

TV's out of my range I am afraid, just bought another Ax off of ebay, 7mm, great, half the price of a new one, that's how I get 'decent' ep's (the only way I can afford it!)

[coffee_prince]

are there any dob 2 inch threaded focusers for a dob?

[Moonshane]

not sure what you mean. do you mean the drawtube? i.e. to enable you to add a filter to something in the focuser to be able to use 2" eyepieces with filters and not have to keep swapping between eyepieces?

if so then unfortunately no nut you could use an extension tube if your out travel allows it (these are usually threaded) or you could use a filter changer but again these need adequate focuser travel.

[rwilkey]

Not talking about the draw-tube, just the diagonal, which can be taken out quite easily, usually held in by 2 or 3 thumb screws.

[Moonshane]

is it not a dob he's referring to?

[rwilkey]

Sorry, if it's Dob, then I stand corrected! In this case the 2-1.25" fitting will take the filter as has already been mentioned, I was thinking of a frac, of course.

[Moonshane]

no worries, maybe it's me that's got it wrong - wouldn't be the first time!

[coffee_prince]

Yes its for a dob, so no threading. Pants