Best Eyepiece for DSO's

[Indibush]

I'll soon be wanting to upgrade my next eyepeice to view DSO's. I'm wanting a good one to suit a Sciywatcher 250PX.

If possible I would like to stick to a 1.25, but if you think a 2" is better for DSO's, ok. I have a budget of around £100, but could go a bit higher.

Thanks in advance.

Tony.

[Paul73]

For DSO hunting you need good contrast. For your scope something in the 18-25mm range is ideal. I'm not sure if they are still around, but the 20mm MaxVision would be my choice. Or, the pricier EXplore Scientific 68° 20 or 24mm.

If you are after nebula. A UHC or OIII filter will help.

Paul

[Dom1961]

This has been reduced, and although shipping may cost more, it's still cheaper than UK http://www.bresser.de/en/Astronomy/Accessories/Explore-Scientific-68-Ar-Eyepiece-24mm-1-25.html

[ronin]

The problem of "best eyepiece for DSO's"  is that DSO's come in an assortment of sizes, and you really need to match the field with the eyepiece to the size of the DSO.

For simple clarity you probaly cannot beat the TV plossl.

The 32mm in yours will give about 37x and so 1.3 degrees, the 25mm will give 48x and just over 1 degree.

As said it depends on the object, M42 is often said to be 1 degree as is M45, whereas the N American nebula is in effect 2x2 degrees, M13 however is 1/3 of a degree. All DSO's but I suspect needing 3 different eyepieces for the best results for you.

[Moonshane]

The answer to this is really "the one that fits the observed object within the field available whilst framing it nicely". As above this will vary by object and scope. A selection of eyepieces to suit different purposes is a good start.

[Indibush]

Yeah, so I'm thinking I might get a couple.

Just want to clear up one think. I was just looking at the focal length to determine how much of the sky I see, but the one in the link above is a 24mm with a 68degree field, but something like a Vixen NPL 40mm only as a 50 degree field. So I'd see more of the sky with the 24mm???

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[Indibush]

I'm looking at the Skywatcher Panaview 2". Maybe a 26mm and 38mm. As anyone tried these?

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[Dom1961]

You'd see a larger area of sky with the 40 mm but the 24 mm will show a larger field when you look through the eyepiece. So the circle that you see when you look through the eyepiece will be bigger in the 25mm. If you have light pollution I think the 40mm will show the sky as too bright. http://astronomy.tools/calculators/field_of_view/ will help you compare

[Indibush]

Thanks for that Dom. That's helped a lot. I see I still have a lot to learn.

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[ronin]

Yeah, so I'm thinking I might get a couple.

Just want to clear up one think. I was just looking at the focal length to determine how much of the sky I see, but the one in the link above is a 24mm with a 68degree field, but something like a Vixen NPL 40mm only as a 50 degree field. So I'd see more of the sky with the 24mm???

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Only a couple???   

At last a set of something or other.

Preferably a couple of sets, just in case.

Cannot have too many eyepieces.

The 40mm NPL although a plossl will have a restricted field, caused by the bit on the end as it acts as a field stop, so you will find it is only about 40 degrees not 50.

[John]

The maximum apparent field of view for a 40 degree eyepiece in the 1.25" fitting is around 43 degrees. In the same fitting a 32mm can have 52 degrees and a 24mm 70 degrees. Each will show you about the same amount of sky but at different magnifications. Personally I think it's advantageous to have a little more magnification fi oyu have some light pollution to content with so the 24mm 70 degree eyepiece is probably the most effective for DSO's under those conditions.

[chrisg18]

 a good quality zoom eye piece is perfect. baader hyperion 8-24? cheaper than 2 eyepieces.

[swamp thing]

Only a couple??? 

At last a set of something or other.

Preferably a couple of sets, just in case.

Cannot have too many eyepieces.

I disagree with this. 

I know this was probably a tongue in cheek post, but this kind of thing can confuse  new comers to the hobby into buying loads of kit they simply do not need.

2-3 eyepieces and a barlow is quite sufficient in any scope for deep sky work. 

[YKSE]

I disagree with this. 

I know this was probably a tongue in cheek post, but this kind of thing can confuse  new comers to the hobby into buying loads of kit they simply do not need.

2-3 eyepieces and a barlow is quite sufficient in any scope for deep sky work. 

Exactly Steve!  if you are more interested in using your stuffs than collecting eyepieces.

[mdstuart]

Just wanted to add that for DSOs there are eyepieces that are better than others in terms of the % of light they let through which is a factor when looking at faint dsos. Basically less glass helps....higher quality glass helps and good coatings help. Some people consider quality ortho eyepieces are the best at this but they have a smaller field of view. If someone can make a 82 degree field of view ortho eyepiece that would be the one for DSos!

Mark

[John]

Just wanted to add that for DSOs there are eyepieces that are better than others in terms of the % of light they let through which is a factor when looking at faint dsos. Basically less glass helps....higher quality glass helps and good coatings help. Some people consider quality ortho eyepieces are the best at this but they have a smaller field of view. If someone can make a 82 degree field of view ortho eyepiece that would be the one for DSos!

Mark

I reckon the Pentax XW, Delos and Tele Vue Delite eyepieces get very close to this Mark. Even though they have lots of glass in them the light transmission is very high - somewhere between 96% and 99% I understand.

They are also a lot more expensive than orthos, granted

[Paul73]

A late warning about long eyepieces in an F4.7 scope.

The 40mm would have an 8.5mm exit pupil. This would be optimistic for the average owl, let alone the human eye. The sky would be very light indeed. I wouldn't go any longer than 30/31mm in your scope (I have the same one).

70° is a nice starting point. 80°+ gets very expensive. 24mm, 16mm, 10mm (and a good Barlow) would be a good starting mix. I obseved for ages with just a 24 & 16mm.

That has grown somewhat....... 30,24,20,17,12,8,6,5. This means that I spend quite a lot of time swapping eyepieces rather than observing. Sounds a bit pointless now that I say it.

You can get really hung up on eyepieces. Get a couple and go from there. In your scope, go for Quality over Quantity every time.

Paul

[Charic]

......I've never tried one but so many references  to the  24mm Panoptic as an ideal wide view EP with its 68°afov ?

 I viewed M31 from my obsy, using my basic skywatcher EPs and just wondered.........is that it?  I then invested in a 60° Starguider which was better in the field of view, but still not brilliant.

Then tried the same optics at a DARK site and was blown away. M31 really shines and is enormous, so I  needed bigger. The 2" 32mm Panaview does the job for me perfectly.

[MarsG76]

All I'm going to say is Televue Type 6. I use the Nager 11mm, and with a 82 degree field of view its AWESOME for close up high power DSO views... combine it with a UHC and prepare to be WOWed with the views.

[Indibush]

Ok, so I ordered the 24mm, but cos of the price drop and everyone talking about it, iv still gotta wait a couple of weeks for the next batch to arrive.

Thanks again for all your help.

Tony

[Indibush]

After a short delay cos of being out of stock, I finally got it.

Thanks to everyone for their help. Let's hope we get some clear skies this week end [emoji437][emoji437][emoji437]

Tony.

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[mdstuart]

Nice!