Jump to content

1912116577_Solarchallenge2022banner.jpg.913a200cf105ddeae9f37765cb1d0c73.jpg

Who uses their refractor without a diagonal?


iPeace
 Share

Recommended Posts

Next session, I am going to try this. Just interested in who does this, and why.

Just to verify: this does give newtonian image orientation, correct? So you need to reverse direction on both axes when hopping or tracking?

:happy11:

Link to comment
Share on other sites

Always use a diagonal with my fracs. Happy to adjust when using the dob.

Only time that I don't use a diagonal is when initially checking collimation or optical axis alignment.

Good luck with the experiement Mike :smiley:

  • Like 1
Link to comment
Share on other sites

Just to expand on why I would consider this at all. I actually prefer correct-image views, and have a very nice amici prism diagonal for this. But what if I didn't, and there was not one to be found? If I was resigned to not having correct image, then why put a diagonal in the path at all? I have yet to try a newtonian, but if all of those who use and love them can cope with the rotated image, then why not? Granted the mount will have to be a bit higher, but otherwise?

Link to comment
Share on other sites

3 minutes ago, Alien 13 said:

The view will be the same as a straight through finder so it could be easy to adapt if you use both.

Alan

Hadn't thought of that. Have yet to try a straight through finder, as well.

:rolleyes2:

Link to comment
Share on other sites

I have tried it a few times.  I think there is an improvement in the image seen in the eyepiece, in particular less scatter, which improves contrast (its not huge, but noticeable) but at remotely high altitudes it becomes quite uncomfortable and my neck is good a holding a grudge so I do not really do it.  Just an occasional experiment.

However, if I had one of these I might consider it more often!

58f62c39c1792_StarChair.thumb.jpg.df8217951790746f0ce704aa7a1e8f52.jpg

  • Like 7
Link to comment
Share on other sites

5 minutes ago, DirkSteele said:

I have tried it a few times.  I think there is an improvement in the image seen in the eyepiece, in particular less scatter, which improves contrast (its not huge, but noticeable) but at remotely high altitudes it becomes quite uncomfortable and my neck is good a holding a grudge so I do not really do it.  Just an occasional experiment.

However, if I had one of these I might consider it more often!

58f62c39c1792_StarChair.thumb.jpg.df8217951790746f0ce704aa7a1e8f52.jpg

Agreed, it would be a sedentary affair, as with binoculars on a deck chair. We'll see how it goes.

Link to comment
Share on other sites

Apparently straight through viewing is popular in Japan. Don't know why this is but Japanese scopes are usually supplied with extension tubes which allow eyepieces to come to focus without a diagonal. My Tak and Vixen have this facility.

I'm getting curious now. I'll have to extend the legs on my Uni 28 tripod and give it a go !

 

  • Like 5
Link to comment
Share on other sites

3 minutes ago, John said:

Apparently straight through viewing is popular in Japan. Don't know why this is but Japanese scopes are usually supplied with extension tubes which allow eyepieces to come to focus without a diagonal. My Tak and Vixen have this facility.

I'm getting curious now. I'll have to extend the legs on my Uni 28 tripod and give it a go !

 

That's the spirit!

:icon_biggrin:

Link to comment
Share on other sites

Of my scopes, the Vixen 102mm F/6.5 seems the best candidate for this. The eye lens of the eyepiece is around chest height at that angle. I'll give it a go tonight if clear :icon_biggrin:

P1050198.JPG

P1050199.JPG

  • Like 3
Link to comment
Share on other sites

3 minutes ago, Dave In Vermont said:

With my Mak?! Let's see here.....

1. Build 7-foot pier to hoist it up high on.

2. Find a Dentist's Chair.

Piece o' cake!

Dave

Yes, yes, just thinking you could try it on Jupiter seated behind the Porta, just for the hell of it.

I can see you building your own dentist's chair, but I stray from the point.

:icon_biggrin:

  • Like 1
Link to comment
Share on other sites

I recall Sir Patrick showing us his first scope, a 3" frac, lovely brass job, that one also didn't have a diagonal. Made around 1910.

:rolleyes2:

Things have moved on, but still, if he could make it work and map the Moon...

  • Like 2
Link to comment
Share on other sites

19 minutes ago, John said:

Of my scopes, the Vixen 102mm F/6.5 seems the best candidate for this. The eye lens of the eyepiece is around chest height at that angle. I'll give it a go tonight if clear :icon_biggrin:

P1050198.JPG

P1050199.JPG

That setup is just so nice.

:happy11:

  • Like 2
Link to comment
Share on other sites

Mind you, this 1990's Japanese postage stamp seems to disprove my theory regarding Japanese observers viewing straight through (I'm just going to slip into my Kimono):

 

 

jpnstmp1.jpg

  • Like 4
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.