9 replies to this topic

[Kim2010]

So I just got a Baader 1.7x GPC. Now, the manual says:

 

The body of the two glasspath correctors 1.25x and 1.7x can be
opened so that you can remove the cemented lens pair and turn it
over to change the configuration from T-2 to Zeiss Ring Dovetail. For
each application, the convex (outwardly curved) lens side must face
the telescope (or sky).

 

How then do I know if the lenses in my GPC are oriented properly? I looked at both sides and I can't distinguish the flat side from the convex side while the lens is in the lens cell. I do not want to remove the lens unless I have to.

[Astrojensen]

 

I can't distinguish the flat side from the convex side while the lens is in the lens cell.

This should be quite evident when looking at a reflection from something with straight edges, like a window. 

 

 

Clear skies!

Thomas, Denmark

[Kim2010]

LOL! I can't really distinguish the sides. I can't even see any reflection on the lens LOL.

[Astrojensen]

The coatings are that good? Impressive. On my older GPC's, it's not so difficult to see the reflections.

 

Here's another method: Use the tip of a plastic straw to gently feel where the surface is and what shape it has. 

 

I don't know your exact setup, but you could also try it in various positions and see what gives the best result. 

 

 

Clear skies!

Thomas, Denmark

[Kim2010]

The coatings are that good? Impressive. On my older GPC's, it's not so difficult to see the reflections.

 

Here's another method: Use the tip of a plastic straw to gently feel where the surface is and what shape it has. 

 

I don't know your exact setup, but you could also try it in various positions and see what gives the best result. 

 

 

Clear skies!

Thomas, Denmark

 

Yup! I guess the anti-reflection coatings are very good (or I am NOT that good? haha).

[Travellingbears]

When you receive 1.25 or 1.7 it’s set in lens holder in proper orientation to fit with T2 attachment. If you are changing to zeiss dovetail/quick release the lens holder will be sitting inside zeiss assembly in opposite orientation (so you will need to flip optics lens in holder).

 

When I switched to quick-release with zeiss ring dovetail configuration I put a kimwipe tissue under lens and used gentle pressure with finger to push lens out of holder (it’s snug fit so does take some pressure). Then I flipped lens over and re-inserted into holder pushing it in as far as it would go. When lens is out of holder the flat and convex sides are more obvious.

 

Dave

Edited by Travellingbears, 05 December 2024 - 05:17 AM.

[Kim2010]

When you receive 1.25 or 1.7 it’s set in lens holder in proper orientation to fit with T2 attachment. If you are changing to zeiss dovetail/quick release the lens holder will be sitting inside zeiss assembly in opposite orientation (so you will need to flip optics lens in holder).

 

When I switched to quick-release with zeiss ring dovetail configuration I put a kimwipe tissue under lens and used gentle pressure with finger to push lens out of holder (it’s snug fit so does take some pressure). Then I flipped lens over and re-inserted into holder pushing it in as far as it would go. When lens is out of holder the flat and convex sides are more obvious.

 

Dave

 

Yikes, don't want to push the lens out anytime soon So I guess I just have to trust that the original orientation is okay to use with a T2 adapter

[Kim2010]

And just like that, I drop my new 2-day-old GPC LOL! Hope nothing was misaligned or anything. The slippery and small little bugger!

[EboO]

It's easier to see with 1.7 than 1.25. Put it on a flat surface and you can see the edges are flat on one face and none on the other.

[ABQJeff]

They are installed correctly by the factory per the instructions they provide in the plastic case, just be sure to know if you have a “Z” model version or not (Z models are installed in reverse).