cheap dso ep

[Naemeth]

I must admit I prefer Globular Clusters to Galaxies from my current observing location. The combination of relatively small aperture and heavy light pollution kills most views of Galaxies, they are only just detectable, sometimes only with averted vision. To me anyway.

[bingevader]

What a minefield!

A fairly baffling amount of info and a rather large selection of EPs!

On a budget though, you won't get a high powered EP with a wide FOV.

You don't have a 10" or 12" 'scope to go with some of the suggestions being made.

What's wrong with the BSTs you have, what don't you feel you are seeing?

I have the 11mm TV Plossl and my back garden is fairly dark, but I often think, "Hmmm, not." and back off to a lower powered EP for DSOs with an 8" 'scope.

I think, like in all things, you have to find what suits you.

To be honest at the moment, I'm enjoying the low powered 2" experience, the highest mag of which is around x67 which fits into Qualia's x60 - x90 suggestions!

As you said yourself, stick with the BSTs, find out what you enjoy the most and then maybe save up and buy something else.

Having said that, those Maxvision (Meade cast-offs) are a blooming good deal!

Cheers

[nightfisher]

I have ordered the maxvision 16mm, thought about selling the 15mm bst but decided to wait and see how the new ep is before moving any thing on, might have to replace my barlow, just not getting on with my current one, should have kept my x2 tal barlow

[michael.h.f.wilkinson]

On the topic of optimal exit pupils for DSOs, there isn't one

I agree that 1.7mm is very useful; my 17T4 delivers that in my C8. However, on certain galaxies 2.2mm is better (enter the 22T4), others do better at 1.2mm (forward the 12T4). I would dearly have a 14mm (XW or Delos?) to get 1.4mm in between. Certain compact DSOs like planetaries can be very good at 1.0mm or even 0.7 mm exit pupil. Wider field DSOs are superb at 3.1mm in the C8 (31T5 Panzerfaust), and even better (depending on conditions) at 5.03mm using the same grenade with the 80mm F/6. Just like I try to match magnification to seeing conditions in planets, I match exit pupil to sky conditions and object properties in DSO viewing. So a 25mm Ortho in a 6" F/5 will deliver 30x magnification, about 1.3-1.5deg TFOV, and a 5mm exit pupil, which is a great combination for quite a few DSOs. The 16mm at 68 deg AFOV will deliver the same TFOV, but at 3.2mm exit pupil, which is often better. A Nagler 26T5 would be awesome, but somebody said something about not breaking the bank

[nightfisher]

Michael, great post, very helpful, i just hope the new maxvision/meade 16mm can take a barlow properly

[michael.h.f.wilkinson]

I had a Meade UWA 14, and it barlowed perfectly. Granted, that was with Meade 2x and 3x TeleXtenders, which are more like powermates than true barlows, but I seen no reason why they should not perform with a barlow.

[russ.will]

I have the ES82 14mm and the ES 1.25" Focal Extender, which is optically exactly what Michael had above.

I don't like, or at least have failed to get on with, barlows, but the Meade TE/ES FE are a totally different proposition. They don't change the physical relationship between the viewer and the EP, like a barlow does. If you have an EP that you are comfortable viewing with, then this aspect remains unchanged with these 4 element telecentrics. They are quite litterally like dropping in a higher power version of your current EP.

The ES82s have a slightly tight ER, so a decent barlow (Revelation 1.25" 2.25x 3 element @ £38?) wouldn't pose too many issues. But I would suggest that if you have invested in EPs at this level, then a telecentric multiplier is a comensurate investment to ensure consistent performance.

Russell