Saxon Binoviewers - Initial impressions

[[1ponders]]

8:00 am this morning :zzz2: :zzz2: :zzz: (I'm on holidays :D ) Knock Knock Knock at the front door. Damn neighbourhood kids. They know my kids are at their moms for a week. Stagger out of bed. "Waddyawont"..... Deep voice from down at the front door..."Australia Post. Registered package for Paul Russell" .....Whoooooosh.....whoops better put some clothes on. Tripped on the dog and nearly fell down the stairs, (hears my wife laughing in the background). "Damn, where are my keys?" In my pants from last night. Race back upstair, yell at the dog, "Get out of my way."

"Don't yell at the dog" :ashamed: Back downstairs, fumble with the keys. Reef the door open, and there it was. Wooo Hooo :cool: Ever tried signing one of those stupid little palm thingies when your still half asleep. Didn't look anything like my signature, but the man from the post was happy.

Me too:D

Back to bed with my package. My wife has a wierd sense of humour. She was laughing at me for some reason. :confused: :confuse2: :confused: Damn 16 miles of sticky tape. Back out to the kitchen for a knife. Yep I've still got all 8 fingers and 2 thumbs. There it is. A box marked "saxon" and two eyepieces neatly wrapped in bubble wrap.

Side note: Australian astronomical suppliers could well take note at how quickly this package arrived. Won Monday lunchtime, delivered Wednesday morning. Now that's service.

Ok First impressions. Heavy! Somewhere round the weight of a 300D. By the looks of it, solid metal, very robust, its going to take some balancing this little beauty. Apart from a bit of dust around the eyepiece holders, no obvious cosmetic marks.Seperate dioptic adjustments for both eyepiece holders, firm but smooth operation. Interocular adjustment, very firm, bordering on stiff. About 55mm to 75mm interocular adjustment. Apart from a few small specks of dust on the prisms, the prisms appear clean and clear with no obvious chips, deformations or inclusions. .....Looks pretty sweet.

The eyepieces, apart from a bit of dust on them, look almost new. Never having tried 40mm eyepieces before I'm not sure what to expect from them. They both however rattle, one is much worse than the other. All threads appear to be firm but when shaken (sideways not up and down) there is a distinctive rattle of movement from one of the lense elements. None of the other eyepiece I own have any sort of obvious movement in the lens elements.


12:30 pm. Can't wait. Cloud and rain looks like hanging round for the evening, so time for a daylight test. This will be a very rough and ready test. I set up my 102mm achro refractor, balanced it with the binoviewers. Its a bit heavier than the canon, the balance point is the same as the mark for when I do extended eyepiece projection, not at prime focus. I set up to view a light fitting on a lampost about 120 -150 meters away. Ok this is where I received my first disappointment. I felt like I was looking down a 2" drainpipe. the field of view was tiny. I thought this can't be right. I removed my star diagnal and tried again. No difference. First reaction. Not Happy Jan. Checked the IO distance and yes I had a single circular field of view. NP there. Slid each eyepiece out a bit, no difference (apart from focus). Hmmmm :confuse3: what's going on here. If this is what they are like, how do they manage to sell any. I took the Binos out and put the 40mm straight in the SD thinking maybe I had a couple of bad eyepieces. No they were fine. nice ling eyerelief too. I put the binos back in. Tunnel vision again. I then noticed something. As I moved my head back from the eyepiece the field of view increased. What I found was that the eyerelief distance had changed from using the eyepiece on its own. And I mean considerably increased. Using the 40mm eyepieces I had to keep my eyes about 75mm plus away from the lenses to get a full field of view. Now this is weird. Problem is at that sort of distance its almost impossible to keep your head still enough to 1. get the IO distance correct, 2. to maintain a static eyerelief distance, 3. effectively adjust the dioptic, 4. line both eyepieces up with your eyes.

Ok experiment time. Is this effect the same with all eyepieces. Unfortunately I don't have any double up focal lenths, so I had to use single eyepieces. OK what did I find. Well my 32 mm suffered from a similar problem but by no mean as bad as the 40mm. Maybe 1.5 - 2 times the eyerelief. 20 mm maybe 1 1/4 times the eyerelief. 15mm and less no observable difference. Ok we're getting somewhere. It appears that the shorter the eyepiece FL the less effect on eyerelief. I have a 10mm "elux" and a 9.7 mm Meade 4000 series (both 52 deg AFOV), so I put both in.

Apart from the very slight increase in magnification for the 9.7, the binos were great. Nice even field coverage. Easy to adjust the IOD to get maximum field overlap, even though it is very firm. Dioptic adjustment was sweet and easy giving as sharp an image as I could expect viewing through a pane of window glass. (remember its raining here at the moment:( ) One effect I have noticed (I tried all the eyepieces in the star diagonal first and again after for comparison) is that the binoviewers give a apparent increase in magnification. Whether this is an actual increase or an optical illusion from a reduced field of view I'm not sure, but I will try to find out. It appears to be somewhere around1.5 times the normal mag for the eyepiece, but this is only a subjective guestimate.

Tht's about as far as I've gotten at this stage. Hopefully this Saturday night I'll be able to to a full field trial. My intial feelings when I first tried them was disappointment. Now I'm definately warming to them. I think that with the right combination of eyepieces they will be a winner.

Watch this space for updates

[h0ughy]

Paul you know Andrews Comm have a bit of a sale at the moment - hint!! :D

[asimov]

You got the knack for tellin' a good story mate!:thumbsup: Nice mini review.

[[1ponders]]

I know h0ughy. Its very tempting. But I'm going to steel myself til at least Saturday. I want to try a few different eyepieces at the IIS SE-Qld get together before I make any decision. Plus I want to see what Mr Taxman says in a couple of weeks :(

Thanks John :D My problem is once I get going I never know when to shut up :lol: Or at least that's what my ex used to say. :P Actually, no she used to say I was full of it. ?????:confused: :confused: :confused:

[h0ughy]

and I agree with Asimov. You do have the knack for spinning a yarn! :thumbsup:

[gbeal]

Paul,
congratulations, welcome to binoview land.
Firstly, and bear in mind I only met you for one weekend, is 55mm close enough for you. (you know what I mean).
Secondly, if you are looking try a pair of any that you can find. I use a pair of old ugly and cheap Celestron Erfles, 20mm and they are simply fantastic. The bino does indeed give an impression of magnification, and it will also depend on whether you are using an OCS or not (I suspect not). Try them on the lunar view and you will be hooked, big time. I have heard that eyepieces can be of a lesser quality when used with a bino viewer. Why? Dunno, but my Celestrons certainly prove this. A star party will be a good time to canvass for duplicate sets and try them. Enjoy.

[[1ponders]]

Don't know Gary, sometimes I think I can see down a single eyepiece with both eye's. As long as its a Panoptic of course. :) As far as eyepieces go, after trying mine today, I think even some old orthoscopics, like those ones you carry around all the time, might do. :P

OCS???

Has anyone bought any of the GSO plossls that Andrews have for $39. If so what are their performance like, (internal reflections, sharpness to the edge etc) in an f/10 scope.

I'll certainly be doing some canvassing this weekend and at the Qld Astrofest Gary. Looking forward to the clouds and rain taking a holiday so I can make use of some new gear.

[gbeal]

Hi Paul,
yep, try as many as you can, but unless you are loaded, and I know you aren't after burgling those Saxons, don't blow the budget straight away on eyepieces. If you have a set of plossls, try some the same, one or two. I actually find that the single set of 20mm's does most I need. I have tried doubles of those cruddy orthos you mentioned, but keep going back to the 20's. The GSO plossls would be a good start. I actually tried a pair of 32mm's but again returned to the 20's.
OCS (Optical Correction System) is a relay lens set to extract the focus point slightly, for use on a newt (where in-focus is normally limited). Mine is a Denkmeir OCS(2"), but there are others. If you have a newt then you probably will need one, but an SCT seems to have bags of focus travel. Watching this space.
Gary

[asimov]

:D Perhaps you should aproach Ken for to get some of his K-mart EPs! {sorry bout that...couldn't resist!}:scared3:

[Starkler]

It would be interesting to see how they perform under the stars . I have read reports of a Chinese made binoviewer on the US market which has a fairly small clear aperture of the order of 15mm causing vignetting on long focal length EPs. Its quite possible the Saxon is the same unit.

[[1ponders]]

You're right Geoff. If you look at the photos, you can see a considerable field stop at the eyepiece end (image 1) and also at the end that goes into the star diagnal (image 2). You can also see in the 2nd image that the prism doesn't cover the whole area remaining after the field stop anyway. Both field stops give a clear aperture of about 2 cm.

[[1ponders]]

Here's a few more images to give you an idea of what the binoviewers look like and their size if you've not seen any before. Plus two sets of images comparing the eye relief. On set for the 40 mm eyepieces and another using the 20 mm. As you can see there is not much difference with the 20s but a huge difference with the 40s. The last image is what I was confronted with when I first looked through them yesterday. You can see why I was a bit concerned :P

[ving]

using the 40s seems to be beter for your posture :P

nice mini no-star write-up :)
you certainly are "full of it" :P
(and have the gift of the gab)

[gbeal]

Paul,
can I suggest you try different eyepieces.
At first glance it looks like the bino viewer is giving you excessive eye relief, but I find this hard to swallow. Do the 40's give a similar eye relief when used sans the bino?
Correct me if I am wrong, but the lightpath within the bino viewer is merely like the lightpath within an OTA, correct?? If so, how come the eye relief changes??
Maybe this is whay I am so happy with the 20mm Erfles.
Gary

[[1ponders]]

I thought the same thing about the lightpath Gary, but if you have a look at the bottom middle two photos, the left one is sans bino and the right one is with the bino. They show the position I have to keep my eye/s to keep a full field of view. Both using 40 mm lenses. The last bottom right image is what the view looks like through the binos if I keep my eye at the normal eye relief distance using just the star diagonal.

Don't know why the eye relief seems to change. The 20 mm images (silver top plossl) shows only a small amount of change. 15 mm and less shows no change. Go figure???

[beren]

:scared3: Paul wonder what a pair of 19mm Panoptics would be like :evil:

[[1ponders]]

As long as their eye relief isn't too long I don't think they will perform any better than any old Celestron :D The field stops are so small in the binos they would negate any benefit of having a wide field of view eyepiece unfortunatley. But its a nice though though. :) In fact that's what I'd imagined them (the binos) to be like, like looking through a widefield eyepiece but using two eyes. I'll certainly let you know how they pan out on Saturday night. With a bit of luck though there may be a couple of good nagler double ups there, or if the field stops are going to be an issue some orthos or radians :)