Spectacles - and I don't mean the galactic kind.

[Thwyllo]

So can someone explain what the issue is around spectacle wearers and telescopes please? I have antimetropia (short sighted one eye, long sighted the other) as well as different prescriptions for distance and close up use. As a long term amateur photographer I've grown used to using eyepiece dioptre adjustment or, in the case of binos, the single eyepiece focus adjuster. While I realise this means someone else viewing would then need to adjust, I'm not clear what problems this can cause with a scope, especially if I'm using an attached DSLR. All the cameras I'd be using (Pentax, Sony and Nikon) have Live View either on the camera LCD and/or via a remote app, so does this mean I wouldn't need to be wearing specs normally, because I can imagine that being a major PITA....I certainly couldn't do it with my cameras.

Any advice much appreciated.

 

Paul

 

[mikeyj1]

Hey Paul,

so viewing or astrophotography?  Viewing as you say, set the scope to your eyesight - I'm mildly short sighted, and i notice the difference when I share binos or an eyepiece viewing.  Of course if your glasses have to cope with other astigmatisms then it may be that you have to wear them.  In which case choose long focus EP's, often the focal point is beyond the glass of the spectacles, so you don't bang your eye on it.

Astrophotography:  just don't rely on focusing by eye - use a Bhatinov mask or similar to get the focus right...

HTH?

Mike

[Thwyllo]

That's useful Mike, thanks. The condition isnt that bad and I tend to default to my left eye for normal photography because that's the long sighted one. In fact I cope without glasses a fair bit of the time...the problem is that your eyes are constantly trying to focus in conflict and that usually ends up with a banging headache scenario.

 

I just got the impression from reading that if you weren't wearing specs when you should, things wouldn't work properly...and I'm guessing it's more with AP so I shall be revving up on Bhatinov masks next!

 

[Louis D]

For visual, if you're mono-viewing (one eyepiece), and you don't have astigmatism, you can probably observe with your eyeglasses removed because you can focus out your distance correction.  As such, you can use eyepieces with limited eye relief.

If you have astigmatism, you'll probably need eyeglasses or possibly a TeleVue Dioptrx to correct out your astigmatism, depending on how strong your astigmatism is and what exit pupil your telescope/eyepiece combination is operating at.  As such, you'll need to use eyepieces with at least 15mm to 20mm of eye relief to accommodate either your eyeglasses or the Dioptrx.

In either case, since you're only using one eye to observe, the other one won't be looking at much.  If it still bothers you, you can cover the non-observing eye with an eye patch.

If you're binoviewing (two eyepieces), you'll need your eyeglasses since your eyes focus at different distances.