Quality of dielectric diagonals?

[Stargazer_00]

Now you've piqued my interest. What do Japanese people do with their refrators?

[John]

Now you've piqued my interest. What do Japanese people do with their refrators?

Many of them seem to like to observe "straight through".

Less glass in the optical train and less chance of any aberrations being introduced I guess.

[E621Keith]

Apparently many Japanese perfered looking up straight through a telescope rather than looking down into the diagonal like the rest of us.

http://blog.livedoor...s/52072785.html

http://ouasc1.blog12...g-entry-54.html

http://www.kyouikuou...02/100221vixen/

http://lh5.ggpht.com/_VEmcsETFzOM/TJOiHc9kHqI/AAAAAAAAAgc/ZFDxtQOfOs8/s1280/IMG_9857.jpg

Takahashi's Japanese product page even shows their UW eyepiece in the straight through configuration.

http://www.takahashi...0715tak-uw.html

[Stargazer_00]

That's quite odd, ergonomically. Also a diagonal adds about 100mm to the focal length from my own experience. Do you they bolt on extenders to get the focal points this way?

[E621Keith]

That's quite odd, ergonomically. Also a diagonal adds about 100mm to the focal length from my own experience. Do you they bolt on extenders to get the focal points this way?

More like we remove the extender when we buy Japanese telescope. Take the Borg 77ED II for example, it comes with 80mm worth of M57 extension tubes behind the focuser as standard (60+20mm). Even though I only use the shorter 20mm extension/adapter, I still struggle to reach focus with one of my 2" diagonal and certain eyepieces. (Can't remember which one, but I think it was the 2" Celestron XLT + 42 LVW that had the problem).

The extension tube confusion was also mentioned here in this Takahashi Sky90 review

http://www.cloudynig...php?item_id=502

[John]

My Japanese made Vixen ED102 comes with the extension tubes needed to allow it to be used straight through. I'll stick it on a tall tripod one day and try it out, Japanese style

[Stargazer_00]

Learn't something new today. Thanks guys

[DanH]

Hi all,

As a owner of a Meade 127 APO, the two first items I changed was the focuser (to go for Moonlite) and the dielectric.

I'm using the Baader ClickLock which replaced the original Meade. The visual quality of the Meade dielectric was OK, but I prefered the more convenient way eyepieces are locked with the Baader one.

Dan

[M4lcs67]

Have made the decision on the WO 2" diagonal, but with the Baader 2" Clicklock. Got to be ultra secure as I am having a dedicated paved observing place built in our garden and I cannot afford to run the risk of it falling out a smashing onto the ground.

[Stargazer_00]

I would whole heartadly recommend a £5 off cut of carpet when observing on concrete. It could save you hundreds.

If the carpet gets dirty throw it away and get another off cut. Or buy carpet tiles and just place a few around and throw them out when they get dirty.

I observe on a grass lawn and any droppages (thankfully to date I haven't dropped anything - im not known for dropping) would only be a cleaning problem rather than a replacement problem.

[M4lcs67]

Hey Stargazing00

That exact thing happened to me a couple of months ago where the knurled screw worked itself loose and the diagonal and my brand new Hyperion fell out. Luckily I currently set-up on my lawn and it fell onto the soft grass, so there was no damage done. With this new paved observing spot we are having made I cannot run the risk, so that's why I want a more secure way of attaching the diagonal and eyepiece. Good idea to look into having some carpet or carpet tiles though. Thanks.