Lens Difference.

[Sheffield Col]

Hi I have a Sky watcher.  D=120  F= 600 mm also a Helios.  D= 120 F = 1000. Most likely made by the same Manufacture's.  Will the the Lenses be the same in both scopes ? I ask because the Helios lens is damaged and the Sky Watcher has some C A. I would like to put the Sky watcher Lens in the Helios if it's possible.  

[RobertI]

Hi, I’m a bit confused, why do you want to put the Skywatcher lens in the Helios tube? You’d have to shorten the tube considerably I think and the Skywatcher objective lens would not perform any better. Have I missed something? 

[dannybgoode]

To expand a bit on Robert's response. No, the lenses will not be the same as the focal lengths of the two scopes are different so they'll have different properties to get the light to focus at a different point

[davidc135]

1 hour ago, Sheffield Col said:

Hi I have a Sky watcher.  D=120  F= 600 mm also a Helios.  D= 120 F = 1000. Most likely made by the same Manufacture's.  Will the the Lenses be the same in both scopes ? I ask because the Helios lens is damaged and the Sky Watcher has some C A. I would like to put the Sky watcher Lens in the Helios if it's possible.  

How is the Helios lens damaged? An edge chip, for example, may not affect performance much if it is blacked out.  David

[Peter Drew]

The lens cells might well be interchangeable but as mentioned, you would need to shorten the Helios tube by around 400mm.  Also, what is the problem with the Helios lens?    🙂

[dannybgoode]

@Sheffield Col - bit OT but WAWAW or UTB (or neither) 🤣

[Sheffield Col]

Many thanks for all reply's.  The Helios lens was badly chipped, the damage was intruding for nearly 40 mm. so it was discarded some time ago.  

[Sheffield Col]

On 07/01/2023 at 12:05, dannybgoode said:

To expand a bit on Robert's response. No, the lenses will not be the same as the focal lengths of the two scopes are different so they'll have different properties to get the light to focus at a different point

That's why I posted, I wanted to know if the lenses' were different.  Cheers. 

[Sheffield Col]

Is it possible to buy a lens to suit my D=120 F= 1000mm. ? 

[davidc135]

 I expect you've seen the FLO ad for the Evostar 120 f8 OTA for £329.00.  David

[Alkaid]

22 hours ago, Sheffield Col said:

Is it possible to buy a lens to suit my D=120 F= 1000mm. ? 

Sadly no...at least not new anyway.  You’d be better off buying a complete scope, 2nd hand.