Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

sgl_imaging_challenge_banner_supernovae_remnants.thumb.jpg.0a6deb4bf0886533629e2bdc08293bc9.jpg

Recommended Posts

My day to day specs are varifocal, photochromatic and plastic lensed. They have some astigmatism looking at stars due to the varifocal design.

So I really need a distance single focal clear lens pair. They must have largish lenses, lightish weight, have an anti-reflection coating and be scratch resistant on the outer surface as well as small field curvature. 😥

So can anyone recommend the lens material which would be best suited to all the above please?

 

Share this post


Link to post
Share on other sites

I have never had any problems with quality plastic lenses. My (Zeiss) varifocals don't seem to produce astigmatism, but there is a gradient of focus over the field of view (a curious field curvature, if you like, so I often don my computer glasses (also Zeiss), which have a uniform correction for a distance of about 1m. I do have to swap around glasses to see in the distance, so I might get some uniformly corrected lenses put into an old frame.

  • Like 1

Share this post


Link to post
Share on other sites

I have varifocal glasses, but also prism and astigmatism, so asked my optician for a pair of distance glasses to the long end of my prescription.

  • Like 1

Share this post


Link to post
Share on other sites

I bought a pair of basic distance-only glasses from eyebuydirect for under $20 shipped.  The basic plastic lens has the lowest index of refraction short of glass, so it adds the least off axis chromatic aberrations to images.  I've not had issues with scratching, but I've also become cognizant of pushing in too far after scratching expensive polycarbonate lenses in the past.

One upside to a dedicated pair of glasses is that they don't accumulate microscratches from daily wear and cleaning, so there's very little scatter or flaring caused by them in use.  I keep them in a case in my astro toolbox of miscellaneous bits and pieces.

  • Like 1

Share this post


Link to post
Share on other sites

I've worn glasses since I was four, they great at sorting out my really bad eyes, to the point that with them I have 20/20 vision.  In addition they sort out the stigmatism that I have (everyone has one apparently).   When working at the scope, I'll tend use my glasses if I need to be sure that the focus is correct for other people.  But if I'm working alone, I'll tend to remove my glasses.   The stigmatism isn't that bad for me, so removing the glasses completely means that I don't have to worry about eye relief and things like that.

Just wanted to point out the obvious that rather than getting more lenses, you might want to try simply removing the glasses from the equation.   (if not for you, then maybe this is useful for someone else reading the thread later)

  • Like 2

Share this post


Link to post
Share on other sites

My last pair of glasses was from a website called speccyfoureyes and were very cheap compared to my old onea.off the high street, but still a 'designer' brand.

You have to wait a little while though, probably 4 weeks in my case, but I was in no rush so I was happy with that.  I'd need to check, but there are the usual lense options.

Maybe worth a look.

 

 

  • Like 1

Share this post


Link to post
Share on other sites

I am very short-sighted, with mild astigmatism. I tend to align with my glasses ON; it's easier to find alpha stars when you can see them 🌟👀. However, for observing, I tend to take them OFF, as I get the full FOV with my Plossl eyepieces, and there is 1-less layer of glass for unwanted reflections, particularly if the Moon is off to one side.

Geoff

  • Like 1

Share this post


Link to post
Share on other sites

I am short sighted and have astigmatism. The reason for mentioning this is that the best solution for any reader will depend on the type of eye problem, as well as personal preference.

Varifoca lenses are a huge set of compromises for image quality and distortion. Particulalry when coupled with correction for astigmatism.
I have yet to be really happy with glasses for serious scope or bnocular viewing.

Whether you are long or short sighted does not matter. It is a simple turn of the focus knob when changing between people at the scope, or between your own eyes.
Not using glasses allows you to get to the best place for the eyepiece. Some eyepieces have short eye relief. That is the distance from the scope eyepiece.

Astigmatism is more of a problem. If it is significant, you must either correct for it at your eye, or at the scope eyepiece.

There are (or were) only a few scope eyepieces with astigmatism correction as an option. When I looked some years back, the prices made your eyes water!

You can go for spectacles that correct at fixed distance, and for astigmatism. These can give a good results.
The distance correction being chosen for example to make reading glasses so you can see charts and fiddly little bits of controls.
The important part is the astigmatic correction.

My preference if for contact lenses with astigmatic correction and fixed distance. My daytime lenses are fixed for distance and good astigmatic correction. They give excellent results in scopes.
The only drawback is reaching for (cheap off the shelf) reading glasses when away from the eyepiece to sort scope controls, charts, etc.

hope this helps.

 

 

 

  • Like 2

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×

Important Information

By using this site, you agree to our Terms of Use.