115 replies to this topic

[nicknacknock]

Rad, can you do me a favor and measure the objective lenses outside diameter?

 

I have something in mind possibly and I need to see if I can swap lenses between a finder scope and this one

[Rad Hard]

Rad, can you do me a favor and measure the objective lenses outside diameter?

 

I have something in mind possibly and I need to see if I can swap lenses between a finder scope and this one

Hello Nick, i do not have long enough wrench to reach the locking ring safely. It is quite deep from the front side of the dew shield, but measuring the part holding it from the back, the lens outer diameter will be between 51mm to 52mm. 52mm is pretty common OD for the guidescope lenses. Diameter of dew shield opening is 54.5mm and thread on the back is 51mm. For completeness, the outer diameter of the this front metal part is 60mm. 

[nicknacknock]

Thanks Rad!

 

Almost done preparing a 50mm binoscope with two Stellarvue finder scopes, a More Blue binoscope base and some other stuff. I will test it and measure the OD of the SV lenses as in the future, I may decide to be an idiot (more than I am at the moment) and upgrade the objectives

[Rad Hard]

I took bunch of small scopes out today and I have to say my Laida 50mm is by no means an good performer. Jupiter was still higher than last time when i tried, but result was quite comparable to last time and there was very significant color "flare" unless the focus was absolutely spot on. It behaves very different from usual blue fringing on achromats. It was rather green or red on in or out side of the focus. I could not get sharp view past about 30x magnification because of that. I looked up the Laida on artificial star afterwards, the diffraction pattern looked ok when looked with O-III filter.

 

On the other hand, i was able to push the my Evoguide 50ED to about 125x with 6mm EP and 3x Barlow. Picture was still pretty crisp, the bands on Jupiter clearly visible. I am not sure if my 50 ED is some excellent copy, but it's totally different league than the Laida.

 

The Svbony 40mm guidescope actually produced more pleasing view of Jupiter than the Laida 50mm. Now those Svbony guidescopes are quite some lottery, i have seen a bunch with quite noticeable astigmatism.

 

What is your experience with your copies, especially the Aliexpress Laida version and TS one? Maybe TS really swaps the lens for something better.

[ris242]

What is your experience with your copies, especially the Aliexpress Laida version and TS one? Maybe TS really swaps the lens for something better.

I regard the TS as better option than say a 60mm single piece of glass in a finderscope. When you stick a smaller eyepiece in it and get the mag up a little ....its better again. But then you lose the widefield of it.

Its beauty is that it is tiny and weights practically nothing. I'm sure it wouldn't compete against the Evoguide.

 

Having said that..........if I want to blow away all the competition I just get out my 60ED but now we are talking 1.5kg...........its not something I could mount on a findershoe.

[RichA]

Here's my Nifty 50 ... a Celestron 50mm f/7.3 Travel Scope with the original .965" visual back/focuser replaced with a 1.25" focuser. With a 16mm Type II Nagler eyepiece, it has a 3.7º fov at 22.5X with a 2.2mm exit pupil. The image is very sharp over 95% of the fov with no visible curvature and an almost negligible CA. However, there is a noticeable curvature across the field when using Tele Vue Plossls.  

 

I use it mainly for a finderscope on a Celestron 4" f/9.8 achromatic refractor. But, I spend almost the same amount of time viewing DSO's with the 50mm as with the 4" scope.

 

Travel-Scope-50-Modded.jpg

Reminds me of when I put a 20mm Nagler on a C90.

[RichA]

I regard the TS as better option than say a 60mm single piece of glass in a finderscope. When you stick a smaller eyepiece in it and get the mag up a little ....its better again. But then you lose the widefield of it.

Its beauty is that it is tiny and weights practically nothing. I'm sure it wouldn't compete against the Evoguide.

 

Having said that..........if I want to blow away all the competition I just get out my 60ED but now we are talking 1.5kg...........its not something I could mount on a findershoe.

The only finder I've ever seen that incorporated a single element were the crappy 5x24mm finders (stopped down to about 7mm) on crappy old 60mm refractors.

[ris242]

The only finder I've ever seen that incorporated a single element were the crappy 5x24mm finders (stopped down to about 7mm) on crappy old 60mm refractors.

should I correct to coke bottle doublet?    (as useful as a single piece of ..............junk)

Edited by ris242, 28 April 2025 - 10:36 PM.

[akdwivedi]

I have the laida version and its not an ed glass. lots of color fringing and the you can see the comma shaped stars on the outer 20% of the glass. other than that it does work very well. the focuser is nice, it does comes into focus with a 1.25 diagonal and eyepieces. and is light enough to keep in your travel bag.

 

I am using it as a Right angle finder scope with a svbony 1.25" diagonal and a 20mm illuminated eyepiece. in that configiration it seems better than the standard 50mm finders which come with celestron c8. 

[Rad Hard]

Yeah, i like the versatility of tube length and the focuser, swapping the lens for the one from Evoguide 50ED would make it perfect tiny 50mm. Evoguide tube is too long to work with mirror diagonal.

Thread on the Evoguide lens cell has few mm larger diameter, than threading on the Laida. Potentially, 3D printed thread adapter/space that will sit between the two threads could be used to simply use the Evoguide lens cell on Laida as needed without removing the Evoguide lens from the cell. Need to check, if there is at least 3mm of clearance it should work.

 

Normally I disassemble almost everything, but the image from my Evoguide is so crisp that I am really hesitant to attempt to remove the lens as the lock ring appears to be glued. I would be really sad if the lens wrench slips....

 

Edit: hmm, this look promising, Laida male thread on the tube end appears to be like M52x0.75 and Evoguide lens cell appear to have M56x1 on first glance (this size is used quite commonly by the SW) with about 4mm of clearance, it would allow the inner ring to have about 2mm wall, so there shall be no issue to print it!

Edited by Rad Hard, 29 April 2025 - 01:49 PM.

[chris charen]

AkiExpress and Ebay are selling this below

 

Cyck52-220ED Guide Scope Guiding Telescope for Sky-Watcher SKY ROVER Telescopes

 

-52 mm.

-220 mm F/L.

-Helical focuser.

-FK-61 Ed glass.

-'Can be used as guide scope, as a straight tube star finder, a 45 degree full positive star finder, [need to add the sky 1.25 inch 45 degree diagonal], can also be used as an ordinary small telescope and can also be used as a camera lens'.

-US $87 Seems too inexpensive to be true.

 

Chris

Attached Thumbnails

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Edited by chris charen, 29 April 2025 - 08:40 PM.

[Rad Hard]

AkiExpress and Ebay are selling this below

 

Cyck52-220ED Guide Scope Guiding Telescope for Sky-Watcher SKY ROVER Telescopes

 

-52 mm.

-220 mm F/L.

-Helical focuser.

-FK-61 Ed glass.

-'Can be used as guide scope, as a straight tube star finder, a 45 degree full positive star finder, [need to add the sky 1.25 inch 45 degree diagonal], can also be used as an ordinary small telescope and can also be used as a camera lens'.

-US $87 Seems too inexpensive to be true.

 

Chris

Have seen that one as well, as i remember there was bunch of sample pictures of buildings, stating that even tho the lens are not perfect, the (aberrations except the CA) are corrected better than with the cheap guidescopes. Looking forward to hear the results. I got my Evoguide 50ED also from Ali, it was cheaper by about 35% compared to when sourced locally, so i took the risk and i am pretty happy with mine, its the most spotless optic i own atm lol.

[Rad Hard]

Say hello to the little EVOLAIDA 50ED

 

After bit of trial and error, i managed to get the threads right and perfectly fitting. Because of the longer 248mm FL, I ended up using the longer extension tube section which has the M48x0.75 thread. Tube internal diameter is bit narrower because of this quite close to the lens, so it maybe obstruct the aperture a tiny bit, its about 15mm behind the lens. Will check this. Btw the thread on the EVOGUIDE lens cell is not M56x1 as I initially thought, but its M56x0.75.

Edited by Rad Hard, 10 May 2025 - 10:14 AM.

[chris charen]

Cyck52-220ED Guide Scope Guiding Telescope for Sky-Watcher SKY ROVER Telescopes

 

I bought the above 50 mm ED scope from AliExpress. Unfortunately it can only be used as a guide scope. [Their advertising is somewhat misleading.] There is not enough 'in focus' to use with any form of star diagonal, no matter how I attempted to configure it. It can be used as a 'straight through' scope, however the helical focus unit is somewhat crude and the eyepiece it self has for come out of the focus unit to get focus. Not a satisfactory arrangement. It is a shame as it has minimal CA and field curvature is also minimal and it is well made. Get the one with the actual Crayford type focus unit. The TS version has ED lens. The AliExpress 'Laida' version is advertised as an Achromatic.

 

Chris

Edited by chris charen, 12 May 2025 - 02:17 AM.

[therealdmt]

 

Say hello to the little EVOLAIDA 50ED

 

 

After bit of trial and error, i managed to get the threads right and perfectly fitting. Because of the longer 248mm FL, I ended up using the longer extension tube section which has the M48x0.75 thread. Tube internal diameter is bit narrower because of this quite close to the lens, so it maybe obstruct the aperture a tiny bit, its about 15mm behind the lens. Will check this. Btw the thread on the EVOGUIDE lens cell is not M56x1 as I initially thought, but its M56x0.75.

 

Very cool indeed; I wish I’d thought of that before I took a different direction.

 

Enjoy!

[Rad Hard]

Cyck52-220ED Guide Scope Guiding Telescope for Sky-Watcher SKY ROVER Telescopes

 

I bought the above 50 mm ED scope from AliExpress. Unfortunately it can only be used as a guide scope. [Their advertising is somewhat misleading.] There is not enough 'in focus' to use with any form of star diagonal, no matter how I attempted to configure it. It can be used as a 'straight through' scope, however the helical focus unit is somewhat crude and the eyepiece it self has for come out of the focus unit to get focus. Not a satisfactory arrangement. It is a shame as it has minimal CA and field curvature is also minimal and it is well made. Get the one with the actual Crayford type focus unit. The TS version has ED lens. The AliExpress 'Laida' version is advertised as an Achromatic.

 

Chris

Thank for the confirmation about the ED lens in the TS version. Probably the biggest strength of this Laida style 50mm is its modularity, the included  2 tube sections already allows different configurations and potentially more can be achieved with standard 48mmx0.75 extension tubes as needed.

 

I have found those 2 adapters on Ali that allows the mounting of the EVOGUIDE lens cell:

This short one is practically what i 3d printed, potentially the narrower tube close to lens creates obstruction:

https://de.aliexpres...ayAdapt=glo2deu

 

This longer one shall be much better in this regard, keeping the 48mm ID for at least 16mm from the lens. Focusing with diagonal will be still possible as for me i got the focus with the focuser about 22mm out.

https://de.aliexpres...ayAdapt=glo2deu