# Worth it to buy 2" eyepieces for Newtonian telescope?

• Stargazing
Greetings to all stargazers!

I am a happy owner of a Newtonian telescope 200/1200 on Dobson mount, more detailed specifications on this link (http://skywatcher.com/product/dob-8-traditional/). It has a 2” focuser with a 1.25” adapter. So far, I was using only the two included eyepieces, 1.25” diameter : Plossl 52° 25mm and Plossl 52° 10mm.

Indeed I’ve observed lot of beautiful objects (planets, star clusters, nebulas and few galaxies), but as I live in a suburb, the nightsky is not that dark as I’d like. To improve my observations of nebulas and galaxies, I am considering to buy a filter. Also I’d like to buy the planetary filters + polarizing filter for more comfortable observing of the Moon. And barlow lens of course too.

That is quite lot of accessories, and before I spend my money, I need to decide whether I keep using 1.25” or will switch to 2” barrel size, or maybe mix of both. Unfortunately, I don’t know anybody in my area using 2”, so I cannot actually try it directly and to have my own experience.

The main advantage of 2” would be to get wide field of view. The main disadvantage is that eyepieces and filters cost more.

Do you guys have an experience with using 2” eyepieces in similar telescopes? Would you recommend it?

Buying and using two sets of eyepieces+accessories. e.g. 1.25” for planets and 2” for nebulas and galaxies seems to be quite costly solution – but maybe you have other experience and a good strategy can be applied. For example, the planetary filters will be most useful for eyepieces with shorter length, esg. my existing Plossl 10mm, i.e. 1.25” fitting. The opposite might be true for nebula filters.

Many thanks for your opinions and recommendations!

Chronos
Gold Member
See here https://www.cloudynights.com/topic/503730-2-inch-vs-125-inch-eyepieces/ for some useful advice. Plossl ep's may not be ideal, depending on your viewing preferences, but, they tend to be fairly inexpensive - which explains why they are commonly furnished with scopes. You may wish to peruse the selection offered by OWL for reasonable options.

Thanks Chronos! I've seen the link, and some more discussions like this one, but I am still not fully decided.

However, I am thinking about the following strategy, which should allow me to invest to both 1.25" and 2" eyepieces in the future, and make the best of a single set of accessories:
- to buy a good 2" barlow lens (probalby 2x) with a filter thread and adapter to 1.25" eyepieces
- to buy all filters of size 2"

For observing the planets, I could easily use my existing 1.25 EP's (or eventually a new one) in combination with barlow lens via adapter. The planetary filters would be attached to the barlow lens

For observing deepsky objects, or just for browsing the sky, I could invest to some suitable 2" ultra-wide EP and nebulea filter, that could be used directly in the focuser or in combination with the barlow.

I am still beginner, so I would very appreciate if you can advise me whether the above make sense and could be working.

I checked the OWL's ultra-wide angle eyepieces - looks interesting. However for EU customers, usually it isn't a good deal to buy in US, due to custom fees and taxes :(

... hmm, maybe 2" barlow and 2" eyepiece is a bit clumsy combination. Wouldn't it be too heavy for my telescope?

sophiecentaur
Gold Member
2020 Award
... hmm, maybe 2" barlow and 2" eyepiece is a bit clumsy combination. Wouldn't it be too heavy for my telescope?
I bought all 2" lenses from the start (about two years) and they are very nice to look through. They are a bit pricy and the choice is limited. Also, my 2" Barlow and lenses were a bit chunky on the 200P Dobs I had for a while. But I had already solved the weight imbalance with bluetack and bits of gash metal when I started putting my DSLR on the focusser.
I am fairly pleased to have gone down the 2" route and have found that second hand astro stuff seems to be well looked after and, of course, not so many people actually want to buy 2". But you already know that Stargazing is expensive in money and time; It's often just a matter of changing priorities and coming to terms and the kids don't need new clothes and shoes every year .

lomidrevo
Do you guys have an experience with using 2” eyepieces in similar telescopes? Would you recommend it?
Two inch eyepieces are nice for giving the appearance of a wide field view. There are some downsides such as cost, spherical aberration, and the constraints on eye relief. You have to hold your eye at a very particular distance from the lens in order to see anything. Narrow field eyepieces are less fussy in this respect.
Buying and using two sets of eyepieces+accessories. e.g. 1.25” for planets and 2” for nebulas and galaxies seems to be quite costly solution – but maybe you have other experience and a good strategy can be applied. For example, the planetary filters will be most useful for eyepieces with shorter length, esg. my existing Plossl 10mm, i.e. 1.25” fitting. The opposite might be true for nebula filters.
Have you taken a look at the Baader hyperion eyepieces? They come with an internal barlow that you can swap out, which allows them to be used as either 1.25" or 2" eyepieces. They are not too costly (~$150). I have a few of them and think they are great, and preform about as well as the much more expensive televue eyepieces. lomidrevo Have you taken a look at the Baader hyperion eyepieces? They come with an internal barlow that you can swap out, which allows them to be used as either 1.25" or 2" eyepieces. They are not too costly (~$150). I have a few of them and think they are great, and preform about as well as the much more expensive televue eyepieces.

Thanks for the hint, I wasn't aware of this. I checked the detail on the baader pages, and it actually looks very interesting. E.g. in case of Hyperion 21mm, I could get 2" eyepiece with focal length 32.2mm by removing the first group of lenses (if I got it right). I will consider this option, for sure

But I had already solved the weight imbalance with bluetack and bits of gash metal when I started putting my DSLR on the focusser.

Could you pls share a photo of your solution, I like this "macgyver style" :)

sophiecentaur
Gold Member
2020 Award
Could you pls share a photo of your solution, I like this "macgyver style" :)
I no longer have the scope but it was very straightforward. I stuck some sheets of roofing lead on the tube, near the primary mirror. There was up to 0.5kg there and easily balanced the DSLR or heavy 2" lenses. Blutack leaves no marks on the shiny white paint if the OTA.
I would endorse the Baader lenses. I bought a Zoom (8mm-24mm) which is very good for sharpness and low flare, except at the 8mm setting, where it seems to drop off a bit. The focus seems to hold out reasonably well for all focal lengths but the 8mm where it goes bad. But you can't have everything for such a reasonable price.

yep, I had a look also at Hyperion Universal Zoom Mark IV 8-24mm eyepiece. Initially I wasn't really thinking about the zoom eyepieces, but for this one, there is lot of very positive reviews. Maybe what is a bit disappointing, the AFOV at 24mm is only 48°.
Is the sharpness at 8mm really that bad?

a small report about my progress (after reading lot of reviews and forums)....

Just yesterday I received the Hyperion zoom from Baader - the bundle including the 2.25x barlow. I had opportunity to try it today early morning, as the sky was clear. However, the moon is still very bright, and was high on the sky at my time. So basically it was the only reasonable target for my test. And I must say, I am really impressed. The image was sharp, providing very pleasant FOV and eye relief as well! I was stunned what details I can see when I attach the barlow. The combo 12mm FL with barlow (giving me magnification 226x with my scope) provided still nice and clear image. However 8mm+barlow (giving 333x) was too much this time - it was quite disturbed by the atmosphere. Maybe next time I have better seeing conditions. However, to be able to focus with the barlow, I had to connect it via 1.25" adaptor tube. The zoom EP itself provides very nice view, sharp and easy to focus. But I can confirm what sophiecentaur said above. At 8mm the focusing is slightly difficult, the stars are not pinpoint sharp.
Week ago I received also a 2" variable polarizing filter from Orion - I can only recommend it. Incredible how many details will pop up when you reduce the incoming moonlight. However this filter I cannot use together with barlow yet, I must get suitable extension+adaptor tube with 2" thread.
And I also bought PanaView 70° 32mm EP from Skywatcher, after reading lot of good reviews when used in scopes similar to mine. It is awesome to have such wide view! Very helpful when searching targets and for observing larger objects, e.g. Pleiades, Andromeda GX. The stars appear pinpoint clear in major portion of the FOV, however at the edges, I can observe coma a little bit. At least I think it is coma, anyway it is not disturbing me! I am still waiting for dark sky to see the whole power of this EP.
And I am pretty sure I will be getting soon a UHC / narrowband filter (also 2" size), but haven't decided yet which brand. Lumicon sounds great, but the price... :(
For the time being, I give up purchasing the color filters for planet observing. After reading more articles and reviews, seems they are more useful for astrophotography. And I read that polarizing filter could be even better help for some planetary details.

sophiecentaur and Drakkith
sophiecentaur
Gold Member
2020 Award
For the time being, I give up purchasing the color filters for planet observing.
Yep. I try interchanging the various colours and any effective change in the visiblilty for different filters tends to be 'forgotten' in the time it takes for me to change lenses. I guess that the faster changes with a Filter Wheel would help to spot the differences. Maybe I haven't spent enough time at it.
The one filter that really makes all the difference is the 13% neutral Moon filter. I don't go blind in one eye with that one!.
Since changing from a Dobsonian mount to an NEQ6, I really appreciate having images staying still, even with high magnification. I know it makes a chap lazy but a GoTo and tracking really helps.
Slippery slope, though. Bread and margarine for dinner these days.

lomidrevo
Yep. I try interchanging the various colours and any effective change in the visiblilty for different filters tends to be 'forgotten' in the time it takes for me to change lenses. I guess that the faster changes with a Filter Wheel would help to spot the differences. Maybe I haven't spent enough time at it.
The one filter that really makes all the difference is the 13% neutral Moon filter. I don't go blind in one eye with that one!.
Since changing from a Dobsonian mount to an NEQ6, I really appreciate having images staying still, even with high magnification. I know it makes a chap lazy but a GoTo and tracking really helps.
Slippery slope, though. Bread and margarine for dinner these days.

Are you using the 13% filter for planetary observation?

The Orion filter I got is allowing to vary the transmission from 1% to 40% - seems pretty handful to be able to adjust it for various situations. For the moon yesterday, I think it could be somewhere between 10 and 20 % when I found the observation most pleasant. In the past, without the filter, it was quite "painful" to look at the moon more than 30 seconds, especially near the full moon. I must have gone partially blind for a few minutes after that - at least that was my feeling :)

GoTo scopes are very attractive, for sure! However, I am still at the beginning with by dobsonian, so enjoying it a lot. But I can imagine that some day in future, I won't resist and will be having bread and margarine for dinner as well :)

sophiecentaur
Gold Member
2020 Award
Are you using the 13% filter for planetary observation?
Only for the moon. I have been using an 80mm f6.5 refractor and the planets are not too bright without a filter. I have a 250mm Newtonian but don't use it much; bulky and heavy to set up and the 13% filter could perhaps help with that one. I try a bit of photography with my DSLR and I am having a problem with contrast range and choice of exposure but I don't think the 13% would help there.

And I am pretty sure I will be getting soon a UHC / narrowband filter (also 2" size), but haven't decided yet which brand. Lumicon sounds great, but the price... :(
For the time being, I give up purchasing the color filters for planet observing. After reading more articles and reviews, seems they are more useful for astrophotography. And I read that polarizing filter could be even better help for some planetary details.
A UHC filter is probably a good investment. I have a neodymium LP filter which I like a lot. Narrowband filters are a different thing though, they are only used for photography.

sophiecentaur
Gold Member
2020 Award
Narrowband filters are a different thing though, they are only used for photography.
The image through a very narrow band filter will be (proportionally) dim. I guess, when fully dark adapted and with a good dark night, you could be in with a better chance of actually seeing something.
But don't suggest that he gets into astrophotography - madness lies there (and poverty!!). I can feel my nerdiness growing by the minute since I got the astroP bug.

But don't suggest that he gets into astrophotography - madness lies there (and poverty!!). I can feel my nerdiness growing by the minute since I got the astroP bug.
I think most astronomy lovers eventually get to the point where they say "I really want this new SBIG, I guess I don't have to eat EVERY day".

lomidrevo
A UHC filter is probably a good investment. I have a neodymium LP filter which I like a lot. Narrowband filters are a different thing though, they are only used for photography.
I was thinking about the UHC filters with narrower bands, like the one from Lumicon, or Orion Ultrablock, or Astronomik. Some other brands seems to name their products UHC, but are more similar to broadband LP filter. At least on the paper, I haven' try one yet.
In my town all streetlight is LED, so I am bit afraid that usuall LP filter won't help noticable

In my town all streetlight is LED, so I am bit afraid that usuall LP filter won't help noticable
In that case your probably right. A wideband Ha filter would probably help with pulling out some nebulosity. If the light pollution is bad in your area, then you may have trouble seeing much even with a filter. The problem being that if the ambient light level is too high, your eyes will not be able to dark adapt enough to pick out faint details. At this point, I think your only options would be to get a larger aperture telescope or travel to a dark location.

davenn
Gold Member
But don't suggest that he gets into astrophotography - madness lies there (and poverty!!). I can feel my nerdiness growing by the minute since I got the astroP bug.

I think most astronomy lovers eventually get to the point where they say "I really want this new SBIG, I guess I don't have to eat EVERY day".

one doesn't have to invest in specialised astro cameras to get awesome deep space images.
a reasonable DSLR camera is very versatile and it's still available for normal family/holiday pix etc

Dave

sophiecentaur
Gold Member
2020 Award
one doesn't have to invest in specialised astro cameras to get awesome deep space images.
a reasonable DSLR camera is very versatile and it's still available for normal family/holiday pix etc

Dave
That's correct in principle but trying to align and focus with an optical viewfinder causes my neck to ache. Live view or a connection to a laptop would help there. Then, old DSLRs have as many hot pixels as visible stars, sometimes. If your skies are good then there's no problem to get the occasional good shot. The Moon is a good girl for that - even when there's a bit of cloud it looks lovely.
I managed, last night, to get one (my first) reasonable picture of the Andromeda Galaxy. I could actually see a blurry image that occupied most of the sensor, with the dark band just discernible. Mostly I just see a small bright blur at the centre. That was between periods of obvious cloud and I got a 5 min exposure. Manual IR remote and timer and stomping around the garden waiting for a possible time slot. Consolation prize at the end was to have a general wander around the sky with the Panavision (spacecraft window) lens. Visual gave much better returns on my efforts but nothing to show for it later.
AS I say - madness and poverty. "We woz poor but we woz 'appy."

In that case your probably right. A wideband Ha filter would probably help with pulling out some nebulosity. If the light pollution is bad in your area, then you may have trouble seeing much even with a filter. The problem being that if the ambient light level is too high, your eyes will not be able to dark adapt enough to pick out faint details. At this point, I think your only options would be to get a larger aperture telescope or travel to a dark location.
indeed, the light pollution is not good at my place, but still is not that bad. For example, I was able find and see the nebulas in Sagittarius: M8, M16,17,18, even though they were not far from horizont (below 20deg) in August. Not mentioning M42, of course. An from planetary nebulas, e.g. M27. However, in M16, the nebuliosity was almost invisible, and I am pretty sure that lot details I missed in case of the others. I hope that a UHC filter of a good quality could improve it. But would be nice to have an opportunity to try such filter before spending money. Indeed, I might end up concluding that the money weren't worth for insignificant difference [emoji20]

one doesn't have to invest in specialised astro cameras to get awesome deep space images.
a reasonable DSLR camera is very versatile and it's still available for normal family/holiday pix etc [emoji2]

Dave
firstly, I would have to solve tracking for my dobsonian. Then DSLR and all the accessories - I might end without any dinner, at all [emoji3]

sophiecentaur
davenn
Gold Member
That's correct in principle but trying to align and focus with an optical viewfinder causes my neck to ache. Live view or a connection to a laptop would help there.

yup and even with live view on the back screen
This why I purchased a Canon 700D ... the LCD panel on the back is fully rotatable ... no more sore necks !!

Then, old DSLRs have as many hot pixels as visible stars, sometimes.

you may be surprised to discover how many hot /dead pixels even newer cameras have
This is why it's a good idea to take dark frames so that the hot/dead pixels can be accounted for and removed

Dave

sophiecentaur