Binoviewers - taking the plunge...

[Bigzmey]

Abbe or Zeiss design Orthos are definitely at the very top for lunar/planetary. The only reasons to skip them are wider FOV or longer eye relief. Eye relief is still better than classic Plossls, though.

[davesellars]

After viewing Jupiter last night and judging how long it takes to go through the FOV in the 18mm BCO and comparing with the approx view (using SkySafari) of the 12.5mm ortho, there is sufficient time for observing it until it needs nudging again. There's not really many options around the 12 - 13mm area anyway especially when you take the physical design into consideration!

So, gone ahead and purchased two of the Fuyiyama orthos...

Also figured it now this completes a nice sharp set cyclops mode for use in 80ED or 102ED refractors especially with the Alt/Az to avoid balance issues changing heavier EPs...

32mm Baader Plossl
18mm BCO
12.5mm ortho
10mm BCO
12.5mm ortho w/2xbarlow = 6.25mm

[Bigzmey]

Congrats on the new Orthos! You got a nice set of sharp glass there. I believe Baader Plossl is underrated (mostly due to slightly smaller FOV). However in terms of sharpness and contrast it is on pair with TV Plossl and I would actually take it over modern version of 32mm TV Plossl.

You can also barlow 10mm BCO to push a bit higher on a good night.

[davesellars]

So these have just arrived... It's cloudy of course but there's possibly a window of opportunity late tonight... fingers crossed!

[Bigzmey]

So these have just arrived... It's cloudy of course but there's possibly a window of opportunity late tonight... fingers crossed!

Image.jpeg

Looking good!

[davesellars]

Fully cloudy and doesn't look set to improve.. urrgh! It seems like the new astro gear curse has caught up with me...

[Bigzmey]

Celestron Plossl, maybe. But these are Fujiyamas, you have to pay your clouds dues.

[davesellars]

A break from the cloud, rain and storms and the sky had cleared around midnight so I quickly popped the 80ED out the door with the binoviewers (however unfortunately made the mistake of not replacing the AZ4 head with the EQ5 which made it awkward to track).

First light with the 12.5mm orthos (gives 144x with the 80ED) showed much more than I expected with only 80mm of aperture. The brightness and contrast was absolutely perfect - at good points in seeing some really nice detail in the main belts was actually visible as well quite a bit of further surface detail. My viewing position was not comfortable though with restricted space at the moment to set up and a pain with the AZ4 movement so didn't spend too long out. I changed to mono mode and took a look at Pleiades and also M31/M32/M110 with the 12.5mm ortho too. Surprisingly M110 was quite easily visible!

These orthos are really comfortable to use binoviewing. The eye relief is just right and they are really sharp to the edge of the FOV. Definitely a great investment!!!

[Bigzmey]

Congrats again on the quality glass and first light! And your BV pairs (25mm, 18mm, 12.5mm) are nicely and evenly spaced by ~1.4x factor. Eventually, I would add 9mm to complete the set. KK conveniently come in that range.

[davesellars]

Thanks Andrey! I think from viewing through the 12.5mm I'm pretty close to the limit especially with only 42 degrees with a manual mount. If someone ends up selling a 10mm BCO cheaply though I may well pick up another.

I may see about improving on the 25mm "pair" especially for something without undercuts!

I think first priority may be putting an RA axis motor on my EQ5... This will help loads to just concentrate on the view...