What is on the rear lens of my Evostar 80ED?

[R1k]

Can anybody tell me what this imperfection is on the rear lens of my doublet Evostar 80ED? Is the coating peeled off? 
 

 It does not shift on rotating the scope or any positional change for that matter.

 

thanks in advance

[Ruud]

It is the strangest thing!

Seems the lens lets more light through in the grey patch. Could it be a hole in a green protective coating that they forgot to remove? 

[Adam J]

I dont know but i dont like the look of it mate.

I would not normally say this but its may be worth unscrewing the objective with a rubber  strap rench on the tube and one on the lens cell (twist anti clockwize).

Try using baader cleaning fluid on it with a pure cotton pad, blow dust off first.

I would be surprised if its the coating coming off.... It could also be liquid trapped between the two lens elements. Have you cleaned it recently what fluid did you use?

Are you 100% sure that it is a new feature?

Adam

Edited August 20, 2020 by Adam J

[John]

It looks like some fluid between the lens elements ?

 

[R1k]

Fluid/water potentially makes sense, got caught unexpected in rain a few days back for a short period... All the other moisture has now gone, just this area remaining, I’m surprised if it is water as it does not change shape no matter how much I change the position of scope etc.  I can’t say for sure that it’s new.

[Adam J]

10 minutes ago, R1k said:

Fluid/water potentially makes sense, got caught unexpected in rain a few days back for a short period... All the other moisture has now gone, just this area remaining, I’m surprised if it is water as it does not change shape no matter how much I change the position of scope etc.  I can’t say for sure that it’s new.

If it will not shift after a week or so then remove the lens cell as above and put it into a sealed bag with some dessicant.

Until then keep the scope in a well ventilated area out of its box. Dont try and do anything like putting it on a radiator or heating it for an extended period with a hair dryer.

Adam

Edited August 20, 2020 by Adam J

[R1k]

8 minutes ago, Adam J said:

If it will not shift after a week or so then remove the lens cell as above and put it into a sealed bag with some dessicant.

Until then keep the scope in a well ventilated area out of its box. Dont try and do anything like putting it on a radiator or heating it for an extended period with a hair dryer.

Adam

Thanks, will monitor and then try this. Cheers 

[Adam J]

1 minute ago, R1k said:

Thanks, will monitor and then try this. Cheers 

oh and should have said, clearly lens cap off.

[R1k]

On 20/08/2020 at 22:50, Adam J said:

oh and should have said, clearly lens cap off

On 20/08/2020 at 22:24, John said:

It looks like some fluid between the lens elements ?

 

Hi guys, just wanted to say thanks - all cleared up after about 5 days of being kept dry and with the dew heater on for most of it. Appreciate the help

[Adam J]

1 hour ago, R1k said:

Hi guys, just wanted to say thanks - all cleared up after about 5 days of being kept dry and with the dew heater on for most of it. Appreciate the help

No problem glad its sorted out.

Adam