Posts Made By: Donald Durbin

Greg,

A 5" scope has a light grasp of 19.6 square inches. A 6" scope has a light grasp of 28.3 square inches.

Given two lenses of a similar type the 6" will transmit more light than the 5" inch. A binoviewer will divide that light between the two eyes. A binoscope will not. The dual 5 inch should have a light grasp of 39.2 square inches. This would provide much more light.

I have a pair of Meade 90's I would like to make a binoscope out of. The problem is the IP distance will be at least 90mm with both scopes side by side. I am thinking about cutting the tubes so they will each focus with dual diagonals and putting my head in between the OTA's

Don Durbin

Hey Glen,

I know how you feel, but at least you were still using both eyes.

I got my Meade 152 ED back last Friday and the skies were very nice that night. I tried to get my nephew to bring over his Televue BV, but he had to work Saturday so he stayed home. My Black Nights are in for the diopter modification. I am also getting a 1.3 OCA.

So I ended up playing Cyclops and it is boring. After using a binoviewer for so long it is tough to give it up.

I can hardly wait to get my Black Nights back again.

Don

Adam,

According to Meade the outer diameter is 8"

See Meade site for all the specs:

http://www.meade.com/catalog/lxd55/lxd55_specs.html

Don Durbin

I guess no one had anything to say about my Black Night Diopter report.

Maybe Diopter adjustments are not provocative enough.

Silly me, this is the binoviewer forum and here I actually tried discussing the equipment.

:>)

Don

Pat,

I really have to go with two. I think that if you use the diopter adjustment as a diopter adjustment for a slight difference in your eyeglass prescription then one would be fine.

That is not how I use my diopter adjustments. I use them as a method for bringing the image to a fine focus. If I were just using my C9.25 with the Crayford focuser then I would not need them. When I use one of my refractors or my 8" Orion Atlas, or my half of the Orion XT10, I do not have that nice Crayford focuser. The diopter adjustments allow me to achieve that level of fine focus in my other scopes.

Also when I adjust the focus on a scope with a standard rack and pinion focuser at high power the image bounces around quite a bit. I find a light twist on the eyepiece is not anywhere near as disruptive to the image and I can fine tune much better.

I still have a bad habit of reaching down to the main focuser after I have tweaked in the image with the diopters but I am trying to break myself of that.

BTW I have not used the Diopters with the XT10 or the Atlas as of yet. I am anticipating the same results in those scopes that I saw with my refractors.

Don

Hi Mark,

I have a Black Night Binoviewer and I have a pair of 24mm wide angle Plossls that I constantly use without any noticeable vignetting problems. These are the EPs that I normally start with. I normally center the object of interest in them and then switch to a higher magnification. They have a really nice wide view and they make it very easy to find objects.

I have also used a combination of 32mm Plossls with a .5 focal reducer with my Celestron 9.25. At that time I did not notice any vignetting problems but I have to admit that I really was not looking for them.


The Black Night has a 22mm clear aperture. The manufacturer says that there is roughly a 10% reduction in apparent field on eyepieces 30mm and higher.

Hope this helps you
Don Durbin

James,

I just up-chucked all over my keyboard. That image is painful!!!

Why do I keep going back and looking at it?

Do you know if she is single?
:>)

Don

Hi,

I am binoviewing with my Meade 152. I have a LX750 mount and it is very stable. I am using an optical corrector but you can bypass the diagonal on a lot of refractors and achieve focus. The viewing angle stinks that way.

I have also had very good luck putting the corrector before the diagonal. I currently have a Sieberts 1.3 OCA in front of a 1 1/4" diagonal followed by my Black Night Binoviewer. I find it works very well. I have also used a Meade 90mm and a Celestron 102 wide field refractor. I did have an AR5 before I got my Meade 152.

Don Durbin

Scotty,

What was the message number?

Don

Mark,

I have to agree with Hinrich.

However if at all possible try to find someone at a star party with a nice set of binoviewers and look through them before you plunk down a lot of hard earned cash.

Don Durbin