BCO 6mm

[Bart]

I just received a new BCO 6mm and was dying to test it on Jupiter. Got up early this morning and it was quite misty. Not ideal. Got J in the ES11mm (x113) and then went straight to the BCO6mm (x208). Yeah, good, but not as clear as I expected. Tried the barlowed 11mm to get close to the 6mm and although bigger, it was still reasonably clear and no worse, I'd say, then the BCO. Went back and forth between the BCO and the barlowed ES and not sure there was much of a difference (except very noticeable FOV and ER!!!). Tried the Nagler 4.8mm (x260) for the fun, haven't used this much sice buying it secondhand. This is going to be lovely when the seeing allows. The ER is bad, but liveable with, especially for the clear views. I'm going to like that a lot I think.

So, first thoughts are not overly impressed. The higher mag barlowed ES gave as good as the views through the BCO and with a lot more comfort. The coditions weren't great, mind you and the mist finally dewed up the primary even. Must try it again in better conditions. Its tiny and light, compared to the big 82 and 100* beasts in the case, almost a plaything. Even the ES 11mm looks like a bit thing compared to it! Mmmmmm, undecided at present.

Barry

[Stargazer_00]

Hi Bart,

A fair summary I'd expect. The ES 82 11mm is a nice eyepiece and will give good on axis views. I did find it gives a little yellow CA on bright objects like Jupiter, especially as it drifts to the outer field.

For the price the BCO should provide good on axis views. Comparable if not better than the barlowed 11mm for a significantly lower price.

Giving 200x+ it won't show its full potential on any but the best evenings but on those nights it will be worth its price. It's light scatter, colour fidelity, sharpness and contrast would probably beat the ES on axis on a perfect night. I believe John said this was comparable to a BGO in performance and the 6mm BGO I have wipes the floor with my ES eyepieces on axis on a good night. BGOs are TeleVue quality on axis, no doubt.

[Damo636]

Nice report Barry! I haven't seen Jupiter yet this time around, actually haven't seen much of anything lately! Stick with the BCO, under better conditions it will probably come into its own. In fairness though, any differences from the barlowed ES will probably be very subtle.

[michael.h.f.wilkinson]

Nice report. The subtle differences I would expect require really good conditions to evaluate, Wait till Jupiter is better placed, and for better seeing, then you might see a difference.

[JamesF]

And bear in mind that the ES11mm new is probably three times the price of the BCO and the Nagler around five times(?).

James

[John]

Interesting report.

Having done a lot of comparing eyepieces over the years, I'd say give the Baader a chance under a number of different conditions / objects before making any decisions. I'll bet there will be some circumstances where the well controlled light scatter of the ortho comes into it's own and it pulls slightly ahead of the eyepieces with more glass in them. Thats why I keep a Baader GO 6mm as well as a Tele Vue Ethos of the same focal length. There are a few occasions when the BGO just pips the Ethos, showing Sirius B is one of them

The BCO's are really, really close to the BGO's in performance except for a softness at the edge of the field of view - that extra FoV that the BCO has over the BGO as it happens !. On the tough target of splitting Sirius I found the BCO 6mm equalled the Pentax XW 5mm with the BGO 6mm just making spotting the "pup" star a little easier.

Much of the time, in the central on axis part of the FoV, many eyepieces do perform very similarly though to be honest.

[Bart]

Thanks for comments. Will definitely keep it and test it under differing conditions. Had a few bob to spare and couldn't resist a 7mm Nagler on ABS today

[John]

When will it end???

I'm not sure it ever does

[alan potts]

Bart,

Nice report Barry and not what I first thought I would read.

I think it may well give you a different story to read when the seeing is better. I find the BGO's I have perform well when the seeing is on song but are much of a muchness when it is only ordinary. Give it time, it think it may well grow on you. I find if I pay no attention to the FOV and ER then differences between my eyepiece and the BGO's is very slight but it is there.

Alan