1.25 or 2 inch EPs?

[johngccfc]

Hi,

If you have the choice, as I have, which would you get?

I've read Robins Eyepiece Guide so have a basic understanding of the differences but wonder what people actually choose in the real world.

For example, do you have a mixture of the two?

Thanks

[M4lcs67]

Yep, I do. Mainly 1.25's, but I do have one 2" which is excellent in my C9.25 ota. My train of thought was to free the capacity of the tube by buying an eyepiece that would do the 9.25 justice. I have a 2" diagonal as well. If possible there is no point in getting a scope with a large apeture then restricting what it can see by putting a 1.25 in it. Of course that shouldn't be the only consideration and I use my 1.25's a great deal. The thing where the 2" eyepiece comes into it's own is when you want to see a large piece of sky when observing a big cluster or something of that kind. You can get it all into the fov.

[planet15]

Most of my EPs are 1.25", but I have a 2" Vixen 30mm EP, which came with the Orion DX300 12" reflector. That 2" EP is considerably larger and heavier than any of my 1.25 Eps, but the FOV is almost double - wide wide FOV is what you get.

Last night I was scanning the sky with it on SW200P, and it was breath taking - I felt as if I was flying across the night sky between the stars.

I don't now prices for these 2" Eps, but I would guess they are more expensive than 1.25" Eps even by looking at the build quality. If money was no object, yes, 2" EPs would be great stuff.

[Stu]

As said, field of view is the reason to go to 2" eps. The field stop of the ep defines the limit of the field and this is of course bigger in the 2".

I believe that the TV Panoptic has the widest fov in the 1.25" format, with a 68 degree afov. In my 106mm, it gives a 2.37 degree field. A 22mm Nagler (2") has slightly higher magnification but a 2.61 degree field. A 31mm Nagler takes this to 3.69 degrees, enough to fit the entire Veil nebula into it which is wonderful under a dark sky.

In summary, a mix of 1.25" and 2" is good, with 2" being great for the longer focal length, wide field objects.

Stu

[johngccfc]

Thanks for the replies. The reason why I'm asking is because I have a couple of 1.25s, a 10mm and a 25mm and wish to get a lunar filter, look into barlows, and perhaps a higher power ep than 10mm.

In my position what would you do?

Thx

[johngccfc]

also, Malc, how many amps is your Maplin power supply?

Thx

[M4lcs67]

Hey John. This is the powersupply I have

http://www.firstlightoptics.com/power/maplins-xm21x-7a-138v-regulated-mains-power-supply.html

[rwilkey]

Hi John, in your position I would try and improve on the ep's that came with the scope before getting a 2" ep, though I have to admit, one of my earliest purchases was the Sky Watcher PanaView 32mm, which I have never regretted, still my most used ep. You only really need one or two 2" ep's, depending on what your viewing preferences are, mine are starfields and open clusters, so the low power 2" ep really suits what I want to see.

[S.A.M]

I think two inch EP's are better, they let in more light to your eye and hopefully have a clearer view of the item you are looking at? No good for high power as I think there are not many EP's below 30mm in the two inch range. As Robin said good for wide field views of which Open Clusters are a favourite of mine.

Peter

[Moonshane]

I have 14 eyepieces and only one is a 2" eyepiece. There's no difference really in quality (assuming the same quality of eyepiece) but 2" just give a wider field, more cost and weight. I'd recommend one wide field low power 2" eyepiece if you can buy good quality but if you have a restricted budget then good quality plossls are hard to beat, especially at longer focal lengths.