Andrews Binoviewer

[dannat (Daniel)]

Anyone tried/seen the $99 binoviewer at andrews? is it ok or a waste of time

[Kevnool (Kev)]

My thoughts also , Is it good or just a toy compeared to others.cheers Kev.

[asterisk (Geoff)]

Originally Posted by Kevnool

My thoughts also , Is it good or just a toy compeared to others.cheers Kev.

G'day Kev

You send me the $99, I will get one for you and bring it up in October (after local testing of course) - then we will know the answer.

Cheers

[dannat (Daniel)]

Geoff, I am quite happy to spend the $99 for the binoviewer

Its the ep's that I'm after, probably some pentax xf's for high power and maybe panoptics for scanning around - if anyone feels generous

Rest assured I will give a thorough test report

[bluescope]

Probably better to go with the WO binoviewer including eyepieces and barlow for $299. It's only money

[wavelandscott (Scott)]

Before you buy anything, let me ask...What is it you want to see/do?

I have a set of the Denk (Big Easy) Binoviewers...and I like them a lot.

For use on the moon and planets (bright things) I think they are the bees knees.

However, for faint fuzzies I much prefer mono-view...While I suspects that big aperture scopes would be better than what I've got, I've found that DSOs are dimmer...I mostly use my 8 inch reflector dob with the Binos or the ED80.

Yes, viewing with two eyes is very comfortable and I do seem to pick out more detail in what I am looking at...is seeing more detail a function of using two eyes, looking longer (because it is comfortable) or some other mechanism I don't know...but I do enjoy it.

With the DSO stuff I've not found the same benefits as the bright objects...I am happy to concede that it may just be me.

With respect to the quality of the Andrews Binoviewers, I don't know as I've never used them...I suspect that they would be okay but not great.

Remember that with Binoviewers you are putting more stuff in the optical train...any decrease in quality along the way will degrade the final image.

I have read widely that some of the cheaper Binos suffer from measurable differences in the splitting of light and than some are brighter in one eye/side than the other...maybe your brain corects for this, I don't know...

[AstralTraveller (David)]

I can confirm that the WO binoviewers do split the light unevenly but in practice you don't notice the difference. You can also get a lot of scattered light if there is a bright object just out of the fov. In most use you probably wouldn't notice it but it has annoyed me during a grazing occultation, where you do tend to put as much moon as possible out of the fov so you can see the star clearly.

Another issue with the smaller binoviewers is that they only have 20mm aperture and there is significant vignetting if you want a wide true fov, especially in fast scopes (btw the path length is about 100mm). I want to be able to use them in the 25cm f/5 newt and so considered the Sieberts OCA with 1, 1.5 & 2 magnification. However with the lowest power I would have 0% fully illuminated field. So I'll have to go for the 1.3, 2 & 2.5 magnification set.

There is another issue and I'm going to start a new thread about it.

[dannat (Daniel)]

I've read on cloudy nights also that nearly all bv's (minus denk big easy) have differing amounts of light going to each eye

Our eyes/brain should be able to put it together, it does this stuff all the time

Unfortunately the budget does not stretch to the denk's, i suppose 99 isn't a lot to throw away given what some spend on this forum

I will try them with tv plossl's 20mm

[PCH (Paul)]

I agree - as with anything, you get what you pay for. I had planned to get a pair of the WO bv's at about $299 or thereabouts. But the guys at Andrews didn't get back to me as they said they would re availability, so I bought the Stellarvue ones from Peter at SDM instead.

These were $275, but they come with a pair of EPs AND a couple of extender tube thingies in case the bv won't come to focus. And they are fantastic on moon and planets, and I thought they were pretty spectacular on dso's as well. For me, I wouldn't be buying the $99 ones. It just isn't enough for a decent quality item.

Just me 2c

[darrellx (Darrell)]

I am very interested in this myself. I have been considering binoviewers for some time, but have been concerned about the focus. I have a Skywatcher 8inch. Apparently the Denks don't have quite the same issue, but they are more than twice the price.

Paul, can you tell me how the focusing goes with your lightbridge? Do you need the extender tubes, or did you also get the adaptor for $68?
Thanks

Darrell

[casstony]

Assuming the Andrews bino's are from the same manufacturer as William Optics/Stellarvue, the main potential problem would be excessive prism misalignment. I'm sure Andrews would swap a bad pair but then you have extra postage to pay. Anyone living within driving distance of the shop could test them at the shop on an overcast, stable day, to check if you can merge the images at 150x.

Stellarvue claim to weed out the bad units reducing your chances of having problems with merging (I don't know if other manufacturers claim to do this quality control).

The Stellarvues I had would reach focus in my Dob with the supplied optical adapter(barlow) and ~1" extension tube. They worked well in my refractor with an Orion shorty plus barlow and they focussed in the sct with no adapter or barlow. A 2x barlow gives something like 3.5x or 4x when used in front of the bino due to the extended optical path.

[casstony]

I purchased a set of Andrews binoviewers just for occasional use on the moon, thinking that as long as I could merge the images these binos would be worth the $99 asking price.

Good Points:
An initial daytime test showed no merging problems in an 80mm f/5 refractor at 80x (19mm eyepieces, 2x ultima barlow). At night I tried them in my 8" f/6.3 sct with a 2" 2x barlow element screwed into the 1.25" adapter of the 2" diagonal, giving about 210x magnification; the image was not sharp due to the observing conditions but merging was easy. I tried loosening a set screw to tilt an eyepiece off centre and this produced a double image, but releasing the eyepiece immediately allowed the images to merge again.

Bad Points:
There are defects in the optical coatings, with 4 small spots where the coatings have not been properly applied. The eyepiece holders are a loose fit on my eyepieces and have only 1 set screw.

Overall I think these binoviewers are appropriately priced and were worth purchasing given that there are no merging issues.