Just got my used Burgess Binos Today
Posted 20 June 2013 - 11:22 PM
I have really become hooked. The binoviewers have given me some of the best solar (white light) observing ever.
The C5 on a Polaris mount pretty much sits outside under my covered patio 24/7 (except when being used of course) and I see these Burgess and Celestron Binos come up for sale often at low prices, and thought it might be good to have a "Dedicated" binoviewer that I could just leave outside plugged into the C5 for birding and for solar use.
I found this pair of Burgess Binos on CN and the price was so affordable that I went ahead and picked them up.
The units have kind of a rubbery texture on the black plastic prism housings, and the seller mentioned that they had gotten "Grabby."
I have had other gear with this kind of rubbery texture finish that failed, and when the unit arrived, I simply used some alcohol, an old Tshirt rag, and a lot of rubbing to clean off the remains of the original failing texture. This left the hard black plastic housing surface exposed, but I prefer it this way.
The units went into a standard 1.25" mirror diagonal and the first thing I did was compared the back focus to the Mark V with the T2 Prism.
Even thought the Mark V uses a larger prisms and a longer light path, when used with the T2 prism, the Mark V actually required less total back focus than the BO when used with a standard 1.25" mirror diagonal.
Why does that matter? The C5 only works at about 120mm with the Mark V/T2, so with the Burgess and standard 1.25" diagonal, it will be less than that. I could not really tell a difference in brightness though, so the difference must be minor (a couple of turns on the focuser knob).
On the sun, I used a pair of 40mm TV Plossls and a pair of generic 32mm. Both worked well enough but the TVs field stop is so close to the end of the barrel that I think it allowed the rear aperture of the bino to come into focus and it must have acted as a field stop because the edge of the 40mm field was very sharp. It was like looking though an eyepiece with maybe a 38 degree apparent field. By comparison, the edge of the 32mm field was very soft because once again, the rear aperture is so close to the field stop (but smaller) so it is like a very soft out of focus field stop.
These are going to be the primary eyepeices though, and for solar viewing, it really doesn't matter. It is hard to see the edge of the field unless the sun's disk extends past it.
The view was really excellent. I did some comparisons with the Mark Vs and the view was not so different as to be obvious for sure. If there was a difference in the amount of detail visible, it was subtle.
I did try them tonight on the moon with the same result. If there is a difference in performance it is pretty subtle. I think the view appeared to have some very very tiny scatter, but not enough to obscure any details. I could pretty much see everything on the moon using the BOs that I could with the Mark Vs.
Of course even 24mm Hyperions had a reduced AFOV with the BOs, but the view was still sharp and crisp.
I think these are actually very nice units, and for someone that wants to test the water, I could almost recommend them.
Almost, but at the same time, there is one reservation.
The one serious weakness of the BOs is that the walls of the diopter housing are very thin, and three nylon screws are used in each diopter to hold the eyepiece in.
Because this wall is very thin, when backing out the nylon screws, it is very easy to turn one a bit to much and have it fall out. The Maxbrights did not have this issue. Perhaps there was a possibility of backing them out far enough, but the wall thickness was such that I never had this issue with the Maxbrights. Tonight, I had nylon screws fall out twice! Good thing I was on my patio and had a strong flashlight. This is a serious flaw. If you use eyepieces with safety undercuts, it makes it hard to know how much you have backed out the screws. This is how I backed them out to far. Didn't like that.
Good news for me is that almost all of my solar observing is going to be with the 32mm Plossls, so I would not likely be changing eyepieces a lot.
Also, considering the tedious nature of changing eyepieces, I did try the little screw on barlow and it worked quite well, and in fact, it may be less tedious to simply pop out the bino and screw on the barlow if more power is needed. I found the step up using the barlow to be quite good for lunar observing. Just enough to drill down on lots of detail, but not so much to cause the image to dim badly.
With the exception of the issue with the nylon screws not having a thick enough wall, I am actually quite thrilled with these. I can now just leave them and a pair of suitable eyepeices outside and not have to worry about having an expensive binoviewer exposed to the elements.
If you use smooth side eyepeices, the nylon screws will not be nearly as big an issue, but it is easy to over-loosen them when eyepeices have safety undercuts unless you work your way around from screw to screw turning half a turn at a time until the eyepieces comes free.
Bottom line? Optically, better than I expected, and with the exception of the eyepiece retention, easy to recommend at current used prices.
Posted 21 June 2013 - 05:32 PM
The first model 24s came with screw type collets, as the earlier bvs, and the later models came with self centering helical collets.
Either way, any Burgess Optical bv should be a nice visual experience. My BO bv is....
Posted 21 June 2013 - 09:03 PM
Posted 21 June 2013 - 09:10 PM
Posted 21 June 2013 - 09:24 PM
Posted 22 June 2013 - 08:42 AM
They work quite well by the way. Have used them several times in the last couple of days.
My only concern is the way the screws work, but I like the tip of using only one screw and may try that.
Again, for me it is not a big issue. I use these mostly for solar and the 32mm Plossls pretty much stay in the barrels. Also, on the moon the other night, I did use the little barlow and it was almost as easy to just scew the barlow in as is was to change eyepeices, and the barlow actually gave a nice amount of magnification and had the addded benefit of increasing the aperture slightly (I did not measure it, but my guess is that it provided enough mirror travel to restore a couple of tenths of an inch in apeture).
I am very happy with the purchase though. They cleand up well.
I am looking for a way to shortent the light path by attaching the binoviewer directly to the diagonal. Hoping to find some kind of threaded step-up/step down ring to allow me to attach the binoviwer directly to the diagonal.
I am surprised that someone has not done this before now, but no such ring may exist.
Posted 22 June 2013 - 12:02 PM
Frankfort KY USA
Posted 22 June 2013 - 07:46 PM
Posted 22 June 2013 - 09:15 PM
Take a look at Harry Siebert's Web site. I just found a similar item under 'Converters' there. $49.
Posted 23 June 2013 - 09:08 AM
Makes the low price not so low, but considering that most of these inexpensive units do not use this kind of eyepeice holder, I guess it is not so bad.
Don't know why I am worried about it though.. I use these almost always for solar viewing, though I did use them with the C5 on the moon last week (Worked great!).
Posted 23 June 2013 - 12:48 PM
Thanks...ordered a pair of Converters from Seibert.
For anybody interested in these eyepiece holders and are unable/unwilling to attempt to navigate Siebert's difficult Webpage, here's the link.
Harry could spend just a tad more time with his Webpage and he'd probably have more customers.
Posted 23 June 2013 - 01:57 PM
Posted 23 June 2013 - 02:07 PM
- BinoGuy likes this
Posted 24 June 2013 - 01:28 AM
Posted 24 June 2013 - 07:09 AM
They were listed on the left side of the page simplly as "Converters" or something.
Thanks though.. Appreciate the effort to help.
Posted 24 June 2013 - 11:43 PM
Ultimately I found your second joke to be even funnier than the first!
Clear Skies Guys,
PS. Binoviewing White Light, H-Alpha, and Cal-K are how I spend many a sunny day. It's always Fantastic!!