Reflector life span.

[lonebod]

Hi, I've been reading a bit about the different telescope types. There is some websites suggesting that reflectors require a lot more maintenance and have a shorter lifespan that refractors.

What types of maintenance over time do both types of scope need and is there a lifespan limit for reflectors?

Thanks.

Sent from my HTC One using Tapatalk

[Bizibilder]

Both will last many years if looked after.  Reflector mirror coatings can degrade with time (again many years) but can be recoated - there are companies that will do the work for you as it requires specialist equipment.  Reflectors also need collimation from time to time (realigning the optics), this is a simple task that only takes a few minutes - once you have practiced it a few times.  Refractors are generally trouble free but may need maintenance occasionally.

[Beulah]

Probably a lot to do with the reflective coating on the primary and secondary mirror surfaces.

It used to be a huge problem in the 'olden days' as the mirror oxidises and the reflective quality diminishes.

Most modern mirrors are overcoated with a layer of silica which protects the surface and extends its life.

The figure normally quoted is between 10 and 20 years for a recoat.

[dick_dangerous]

Other than the fact that one of the tube rings for my old TAL 3.5'' reflector smashed, it is still in perfect working order after nearly 20 years. Probably needs collimating though...

DD

[lonebod]

Probabrly had something to do with me looking on sites about seconds had scopes.

Was thinking more about a new scope anyway. A skywatcher 200p or 250px if I can afford it is on the cards.

Sent from my HTC One using Tapatalk

[ronin]

The life will depend on the quality of the aluminium coating and the quality of the protective coating.

Then comes the atmosphere and the care taken. As moisture tends to be mildly acidic and carries more then expected bits in it, it all factors in.

If you are in a clean air area then life will be longer, on the down wind side of a steel or chemical works then not so good. Possibly the same for coastal regions, that salt air isn't going to help.

Luck will also play a part, a small pinhole in the protective layer and that points will fail quick.

I would expect 5 years fairly easy and have read that at 10 years you should look at a mirror and consider the condition of it. A gradual deterioration is often not noticed until a new item is placed next to it.

I would ignore any claims of mirror life as these can be based on wrapped, protected and in a temperature and environmently stable condition, not open to the elements outside on a cold damp night.