Problem with sv406p objective (2 Viewers)

[LRL]

Hi
Recently ive noticed some dark spots in the variable 20-60x objective of my svbony sv406p .

Ive tried to remove them , but it seems like they dont disappear , even with a deep cleaning, so my idea is to get a new objective.

I read some other threads about this subject , but i only saw recomendations about fixed objectives , but i would prefer a variable one , and, if its posible, something better than the standard svbony objective , because i would like to increase the image quality a bit .

Thank you in advanced.

 

[jring]

Hi,

dust inside an optical instrument is rarely visible in use. Can you see the spots in the image when using the scope?

As for a better astro zoom eyepiece, the Baader Mk IV comes to mind - quite nice but not cheap. It seems to not come to focus in the 406p, so it is not an option unless modified.

SVBONY SV406P 80ED Spotting Scope 20-60Zoom

Anyone got any opinions on this scope? Seems to tick all the boxes for a price of only £320 new. This would be my first scope.

www.birdforum.net

It is also not sure, if a better eyepiece, be it zoom or not, will actually yield better image quality at higher magnifications... it could also be aberrations in the objective.

Joachim

 

[LRL]

Hi Jring

I can see those black spots perfectly in a light-colored background , and also in other situations if i really put effort into it. I dont know what it is , but i always thought that it could be trapped moisture inside the objective

That thread that you link is the one that i read some time ago , but i only saw objectives with fix magnification , and for me i think it wouldnt be ideal for use in the field .

As for the Baader Mk IV , how could i modified it in order to work in the sv406p? Any other options ?

Thank you very much

 

[Binastro]

LRL,

The optics you describe are eyepieces.

The large lens at the front is the objective.

Sometimes with zoom eyepieces spots may be visible at some magnifications but not others.

I am not sure if you are describing dust, possible fungus or something else.

Is it on an optical surface or between cemented doublet components?

Could you send a photo of the offending spots?

Regards,
B.

 

[jring]

Hi,

as for ideas how to modify the Baader to work on your SV406p, see post #20 in the thread mentioned above. You need to get further in with the EP to reach infinity focus - so unscrew everything which prevents that or even machine it to remove offending parts.

But first of all, I would strongly recommend to star test your scope. If that shows a crisp image at 60x and the star test does not show major aberrations, you can think about buying an expensive zoom EP.

Joachim

 

[LRL]

LRL,

The optics you describe are eyepieces.

The large lens at the front is the objective.

Sometimes with zoom eyepieces spots may be visible at some magnifications but not others.

I am not sure if you are describing dust, possible fungus or something else.

Is it on an optical surface or between cemented doublet components?

Could you send a photo of the offending spots?

Regards,
B.

This is the best I can do to try to show those spots.
In the photo they appear translucent , but in reality they are black .

 

[Binastro]

Hi LRL,

They are not clearly seen, but may be droplets of grease.

On which surface are they?

Internal or external surface?

Regards,
B.

 

[LRL]

Hi LRL,

They are not clearly seen, but may be droplets of grease.

On which surface are they?

Internal or external surface?

Regards,
B.

It seems internal , because im not able to clean them

 

[Binastro]

It could be grease that has perhaps been in a hot place or just broken down and ended up on an internal surface.

It is not fungus.

It also does not seem to be in a cemented pair of elements.

I don't know if it is covered by warranty.
Perhaps send the photo to the place you bought it or to the manufacturer.
Manual focus might show the spots in focus.

I would probably take it apart and clean it, but zoom eyepieces can be complicated and getting the elements back in the right place may be difficult.
They could also just fall out, and if you don't have a section drawing it may not be possible to reassemble.

If out of warranty, the easiest thing is to buy another eyepiece, either the same or a different eyepiece.

To ask a repairer to disassemble, clean and reassemble will probably cost as much as buying a new eyepiece.

Regards,
B.