AstromaniaStereo Binocular Viewer for Telescopes - Featuring an Adapted 1.25" Barrel and Two 32mm Plossl Eyepieces - Almost 3D Observing with Both Eyes and Enhance The Image Contrast

Tested with F5 achromatic refractor. Not the ideal telescope. Very good image of the moon although it did not focus directly, if it did with both barlow lenses included. Saturn although small, its characteristic is noted. It was also tested with svbony 17mm plossl eyepieces. At the moment with this F5 telescope, I don't think it's necessary to try more lens combinations.UpdatedAfter more than a year, I will explain according to my opinion why they are not for everyone.Sometimes I have not been able to emerge the image. But more than once I have achieved more than 240x on the moon. They have worked well on planets and some nebulae and open clusters. Sometimes small objects do not emerge but large ones do. They improve contrast at the expense of less light, although in general the image is more relaxed with both eyes. That is why I have purchased several sets of eyepieces that work very well on them and are not extremely expensive.svbony40 plossl25 plossl15 red line10 flat field " does not have a slot".These pieces can be unscrewed from the barrel and inverted. Then the slot would be at the bottom.Another high quality item was the oca 2x from William Optics which is sold by Agena. This provides better image quality than the 1.85 of the binoviewrs.Why give them more than one chance if the image doesn't emerge the first time?If you have not rested well even though you feel well, the image may not emerge.Do not drink alcoholic beverages before or during use. It is an excellent test to verify that you are no longer well even if you feel wonderful.If you take any medication, make sure it does not interfere in any way with your alertness. Even if you feel fine, it will probably cause problems for the image to emerge.The first time, I recommend trying during the day with some large and one small distant object. Also try starting to focus without adjusting the eyepieces and then adjust gently.At the moment all the named combinations work, some if not others, with these telescopes. In a refractor it is ideal to have, if applicable, 1.25 and 2 diagonal to be able to focus certain combinations.120mm f5 refractor105mm f13 mak90mm f5.5 refractor200mm f6 dobsonianBut if you want to keep it simple, I only recommend as an improvement, the oca from William Optics.

Not the best on the market but good for the price.

I really wanted to make these work but I found I was spending more time fiddling with these bino viewers than observing. There are number of issues:- width adjustments were difficult because they were too loose and collapsed too easily- right eyepiece holder didn’t tighten correctly. It would just keep spinning.- merging issues are difficult to correct. It was almost impossible to get images merged and focused in both eyes- 1.85x and 3x barlows showed heavy distortion. I had to use my own Barlow to get better results.- included 32mm eye pieces have too much eye relief. You have to pull back too far too see well.- compression rings don’t hold eyepieces with grooved barrels which are fairly common.Overcoming all these issues yielded nice results but required too much time and effort to achieve. I was also disappointed by how dust was inside the viewers. They didn’t seem like they were new. In the end I gave up after a few weeks of trying to make them work and returned them.

This is a surprisingly good binoviewer, especially considering the price. Even using a small 80mm refractor, images of the moon and planets have plenty of brightness and excellent contrast. It comes with a pair of 30mm Plossl eyepieces, and two nosepiece Barlows. These are needed on some scopes to reach focus, due to the needed backfocus of most binoviewers. Also, this, and probably most other units work better with eyepieces having no undercuts or taper.It gives sharp, contrast images, and the binoviewing experience is much more comfortable with both eyes than with just one. Because of this, low contrast detail, such as found on planets, is easier to detect.A well made unit capable of providing a lot of enjoyment.

I used this for white light solar observing and it has passed amazingly. Very sharp!My unit came with scratches on the body hinge cover and upper eyepiece clamps but hearing about some other issues on these I am so far going to keep it. Perfect clean optics and mechanical is smooth. Eyepiece holders hold secure and eyepieces can be changed out. Hoping my 3D ones work. IPD distance is high. I read minimum is 55 to 60. Mine is around 62 and I can just merge the images. Any wider and I could not use it. I like the compactness and weight of the unit is the best I've used. Very happy with the unit and a bargan over other models by far. I really believe we are getting a deal on these because of assembly cosmetic second but they cannot be easy to assemble which is probably an understatement. Well done. Everyone should have one.Edit: returned and purchased another that is near perfect fit and finish. Very surprising to see clean views in these.High mag is better in better viewer, to be sure but amazing for price.

These seem well made and perhaps they are. However as soon as I tried to put two eyepieces into them, it comes with two VERY cheaply made eyepieces not worthy of use. I put two quality 32mm eyepieces into them with the typical retention rings now pretty standard on most eyepieces and the compression ring system falls into the rings and will not hold them. For me they were worthless. I can't attest to the BAK-4 prisms or the other elements since they are of no use to me and are going back. I did like the twist lock but these require further engineering to accept all 1 1/4" eyepieces. NOT RECOMMENDED at this time.