Dust in refractor

[ItIsOnlyMe]

As a new owner of half decent refractor for the first time can anyone advise if it normal for there to be a little dust entering the OTA and finding its way to the inside of the objective lens.

I suppose I was expecting the OTA to be sealed like a camera lens, is that not the case?

[Grotemobile]

Hi, i have a vixen 102mm F10 scope.The end of mine just unscrews off .The inside of mine was very dirty.I used Distilled water & a Lense cloth to clean it off.Its like looking through a different scope.

Well worth doing.

Steve

[Mark Scott]

Which refractor do you have? It would help if we new as it's not in your signature.

[ItIsOnlyMe]

Its a Starwave 102.

Grotemobile - the dust is inside the tube, not on the external face of the objective, though that was dusty too and I cleaned it with a lens wipe.

[Zakalwe]

Camera lenses aren't "sealed".....quite the opposite. In fact the 100-400 Canon is often referred to as an "air-pump" due to it's construction (push-pull to focus).

Some dust is unavoidable, and will be virtually invisible when the scope is in use. Be wary of cleaning lenses...its easy to scratch the coatings that have been applied to the lens. If you are imaging, then flats will remove the effect of dust in the optical train.

[ItIsOnlyMe]

Camera lenses aren't "sealed".....quite the opposite.

Just goes to show that you do learn something new every day.

Thankyou

[Trickystar1]

A little dust won't harm the viewing capabilities of the scope. A good technique that I have used is getting a vacuum nozzle down there, although be careful not touch the optics in the OTA!

[Grotemobile]

Hi. That is were mine was on the other side of the lense. The whole object lense on my refractor just un srews.My lense is totaly clear.

No coatings at all.It is a doublet.I dont know about yours.

Steve.

[MjrTom]

Hi. That is were mine was on the other side of the lense. The whole object lense on my refractor just un srews.My lense is totaly clear.

No coatings at all.It is a doublet.I dont know about yours.

Steve.

Thats unusual, my SP102M has a multicoated lens

[ItIsOnlyMe]

Sounds like I should stop giving the dealer a hard time :-)

[Grotemobile]

The lense is totaly clear.I was suprised as well.Its a doublet.Its a

heavy old lump as well.I took this picture of Saturn with it over the

weekend, so it there does not seem to be a lot wrong with it.

Saturn 11_02_2012 06_34_59.tif

[sound]

Good Evening itisonlyme -

I have also been looking at this scope as a possible purchase , but was concerned with the dust issues - i see you only ordered your last week and you mentioned in your post that you had spoken to ian King and he assured you that the dust problem was resolved.

Can i assume from this then that perhaps the dust issue has not been sorted ? , was it a lot of dust on the lenses ?.

it is good to know that the dust does not necessarily affect the views or photo's but a bit concerned paying out that sort of money i would want it near perfect ?.

[x6gas]

Is there any flocking material inside the OTA that could have shed during shipping?

[E621Keith]

When you said inside, do you mean the surface facing the eyepiece or the two surfaces facing each other between the two lens element. I wouldn't worry if it was the first, dust could get in from the eyepiece end.

[ItIsOnlyMe]

When you said inside, do you mean the surface facing the eyepiece or the two surfaces facing each other between the two lens element. I wouldn't worry if it was the first, dust could get in from the eyepiece end.

Thanks Keith

Been unwell for a few days. Intend to take a look shortly.

Suppose I have to try and move/remove the dust to work out whether it is internal to the OTA or actually between elements of the lens. Will take the focuser of tomorrow and see if I can work it out. Keen not to damage the unit in trying to work it out as the dealer has offered and exchange, just keen not to send it back if it isn't an issue.

[ItIsOnlyMe]

Is there any flocking material inside the OTA that could have shed during shipping?

Hi x6gas, no, there is no flocking and the dust is a light colour.

Thanks

[ItIsOnlyMe]

Good Evening itisonlyme -

I have also been looking at this scope as a possible purchase , but was concerned with the dust issues - i see you only ordered your last week and you mentioned in your post that you had spoken to ian King and he assured you that the dust problem was resolved.

Can i assume from this then that perhaps the dust issue has not been sorted ? , was it a lot of dust on the lenses ?.

it is good to know that the dust does not necessarily affect the views or photo's but a bit concerned paying out that sort of money i would want it near perfect ?.

Hi Sound,

I have been in contact with Ian since and he is the absolute model of professionalism and customer service. He has offered to swap out the scope or refund. He assures me that he visually checked the scope and I that it was free of the previous dust issue which is not what the issue is with this scope.

I believe the dust issue here is both an expectation issue on my part ( I didn't realise the tube was open ended) and that due to the previous issues I am over sensitive to looking for dust. Well you would be wouldn't you?

I have cleaned the external dust from the face of the objective and know I am feeling a little better (very bad flu) will try and get to the bottom of whether the internal dust is "mobile" and has come in through the EP hole down the tube onto the internal face; or it is "fixed" and is withing the lens cell. With the "fixed" dust being an issue and "mobile" dust being just how it is.

Will update when I have checked.

Otherwise the scope looks a winner and I am keen to keep it if I can. As others have said the focuser looks like you could hang a bus off it and compared to the one on the Skywatcher 300p it is a work of art.