Meade 9.7 series 4000 or Baader BCO 10mm or another suggestion

[spaceboy]

OK so I have so far narrowed it down to either a Meade 9.7mm series 4000 with a FOV of 52° and eye relief of 5mm costing £26 or for £50 a Baader classic ortho 10mm with "approx." 50° fov and no mention anywhere of eye relief. The Baader is my first choice out the two but coming close to double the cost I have my doubts I will see a great deal of performance difference with a f/8.33 scope. I did though want a 10mm eyepiece to offer 60° fov but other than the TV radian I can't say there is a lot to pick from. Needless to say the Radian would be double the cost again and that would be used.

Out of the Meade and Baader which would get peoples vote. It would be nice to know how the eye relief differs between the two as well as the eye lens size if anyone has this spec to hand ??

Or is there a hidden gem out there I have over looked ?

[bish]

Do you live near Dudley? I've got a  9.7mm 4000 if you wanted to borrow it to try out.

[John]

An ortho will have eye relief very similar to a plossl of the same focal length.

For an eyepiece that is optically in the top drawer even compared to eyepieces such as the 10mm Delos I reckon the 10mm Baader CO is excellent value.

Frankly I'd happliy fork out the extra to get the Baader CO over the Meade 4K plossl to be honest with you, even if the Meade was one of the better Japanese made ones.

 

 

[Charic]

I've always wanted to own a Plossl set, and of the few I own already, Im favouring the Revelation Astro eyepieces.

 

[Highburymark]

The eye relief is pretty tight for both but is slightly more generous on the Baader - an estimated 8mm. 

[spaceboy]

Thanks for the replies guys.

I admit I was always leaning in the favour of the Baader so I think I'll hold out a little longer in the hope one will come up used..... but in the mean time if your offer stands Bish and I may take you up on it if you don't mind? The plan is to use it for solar observing so I could always bring the scope to you one clear day and we could share thoughts on the Meade's preformance ??

[John]

If it's solely for solar observing then the plossl might be just as good. The Baader CO has a definite edge on nighttime stuff. I don't do much solar but when I have (white light filter and PST) I've found low cost plossl eyepieces seem to do as well as much more exotic eyepieces.

 

 

[spaceboy]

This was my thinking when comparing prices as well as performance. A slower scope plus only really using the centre of view to observe due to the sweet spot. I guess I should have mentioned all this in my opening post

As mentioned before I was hoping for something around 60° fov as I find this works well. I know you don't achieve the whole 60° due to the restrictions imposed by the blocking filter but you do seem to sense more room around the disk despite the apparent vignetting.

[bish]

No problem. I use it for solar too. You're welcome to come over for a tea and solar session - you're more than welcome to borrow it if you want.

[spaceboy]

Thanks mate.

[YKSE]

I would go with John's suggestion, BCO over Meade plossl everytime.

Abbe orthos usually have slightly longer ER than plossls, 0.8x of focal length compare to plossl's 0.7x, it can be easily seen from BCO's specification table and Televue's table for plossl.

Orthos are known to have better scatter light control, which is one of the most important charateristic for observing bright objects like the Moon, planets and the Sun. Better coatings reduce reflections and increase light throughput, the technologic development in coatings is also in favor of newer BCO than old Meade plossl.

Nowadays plossls (Meade included) are in fact Achromat pairs, not asymmtric doublet as the original design, the central sharpness is not as good as Abbe ortho, as we can see in the diagrams in the middle of  this page:

http://www.telescope-optics.net/eyepiece_aberration_2.htm

The difference is not much, but adding all these factors up, we have a self-evident winner here, IMHO.

 

[spaceboy]

How the hell you found that spec sheet YKSE I will never know as I tried every key word I could think of in Yahoo searches (most brought up more [removed word] than eyepieces) but thanks for posting.

I think I was always going to go with the ortho tbh as I had the 6mm and couldn't fault it, The only reason I let it go was it wasn't parfocal with my Fujiyamas. Plus it will come in hand for night time observing I'm sure.

Just a case of waiting for a used one now. I would buy new but whenever I buy something new a week later I can guarantee a mint used one will come up for half the price

[YKSE]

Just my OCD with numbers, had to dig it out for my stuffs.

[spaceboy]

Thanks for all the advice guys.

After some time using an old Helios silver/ black top 10mm Plossl a 10mm BCO came up used so I decided to take the plunge.

I have had a few sessions comparing the two but straight away the larger eye lens of the BCO helps get more comfortable settled in to position and there is a noticeable if not small increase in eye relief over the plossl.  I have mentioned before in a thread some time ago that the cheap silver top plossl does a remarkably good job in solar scopes

Again there is a subtle improvement in edge correction in the BCO but if you really look for it you can see some softness. This is not something seen in the higher end orthos but then again the BCO at 50° AFOV offers a further 8-10° fov over traditional 40-42° orthos so in truth the edge performance is more than acceptable even to a picky eye.

I find daytime observing comes with it's own challenges and unlike at night where you can move on to another target if you feel eye strain or pivot to one side to block stray light and for this reason I have found my first choice eyepiece for solar observing is the BST starguiders with long eye relief, large eye lens and screw up eye guard. They offer excellent views in white light and Ha and are far more comfortable to use during the daytime than other eyepieces I have experimented with. I do for some unknown reason in any ortho I have used for Hydrogen alpha found a slight flat spot on the solar disc? It was this reason that lead me to eventually going with the BST starguiders and the same phenomenon is present on occasion in the BCO. It isn't always apparent and focusing often tweaks between edge features and the centre disc becoming more contrasted / sharp. For want of a better explanation it is almost as if in orthos the depth of the solar surface is more obvious. I'm sure this can't be the case as I'm sure when you focus an eyepiece it is in fact focusing on a point in infinity and not an actual point on the surface ????

All said and done on this occasion I needed a 10mm focal length ep to fill the magnification gap left by the 8mm and 12mm BST which the BCO seems to comfortably fit the bill. The longer eye relief and larger eye lens of the BCO is more comfortable to use over the plossl and the winged eye guard is a god send for daylight solar observing.

 

 

[YKSE]

Looking good

I find the volcano top 10mm BCO does give more usable ER. I can tilt my head somwhat to see the field stop while wearing glasses, but couln't do it with Maxvision 16mm, despite 12mm ER there (the concave eye lens in MV shortens the usable ER too).

I too,  find the winged eye guard very helpful in solar, my 18mm BCO pair have always the eye guards on for shielding off the Sunlight.