• Hi, I am the owner and main administrator of Styleforum. If you find the forum useful and fun, please help support it by buying through the posted links on the forum. Our main, very popular sales thread, where the latest and best sales are listed, are posted HERE

    Purchases made through some of our links earns a commission for the forum and allows us to do the work of maintaining and improving it. Finally, thanks for being a part of this community. We realize that there are many choices today on the internet, and we have all of you to thank for making Styleforum the foremost destination for discussions of menswear.
  • This site contains affiliate links for which Styleforum may be compensated.
  • STYLE. COMMUNITY. GREAT CLOTHING.

    Bored of counting likes on social networks? At Styleforum, you’ll find rousing discussions that go beyond strings of emojis.

    Click Here to join Styleforum's thousands of style enthusiasts today!

    Styleforum is supported in part by commission earning affiliate links sitewide. Please support us by using them. You may learn more here.

Ask me about Eyewear!

mhip

Distinguished Member
Joined
Apr 8, 2020
Messages
8,364
Reaction score
8,747
A question: I am seeking the perfect pair of pantos. Specifically, I want a fairly full, nearly perfectly round glass as opposed to the flattened version you find in most contemporary pantos. See, for comparison, one of Truman's glasses.

Most models I have found either have too great a difference between width and height of lens or mess up the shape somehow (too square). Savile Row seems promising though isn't exactly what I am looking for. Does anyone know of alternatives? Surely it cannot be too difficult to find a good pair of wire frames.

View attachment 1455163
TVR just released the 505.
Handmade, Japanese. Google should work.

@JDelage
I have the 506 in black driftwood and I like them a lot. I'd describe them as JMM-lite. Chunky acetate, but not as chunky.
All limited runs, handmade.
 

JDelage

Senior Member
Joined
Oct 16, 2008
Messages
431
Reaction score
321
What does "base 2" means when you read a lens description (e.g., CR39 base 2)?
 

faue

Senior Member
Joined
Dec 21, 2018
Messages
414
Reaction score
4,457
What does "base 2" means when you read a lens description (e.g., CR39 base 2)?
Base curve. i.e. the front surface power.

Quick overview if anyone cares — ophthalmic lenses are almost invariably meniscus lenses with a plus powered convex front surface and a minus powered concave rear surface. Most lens manufacturers have a few standard base curves and then create the Rx by picking a rear lens power to achieve the desired back vertex power, which is what is actually measured and what you are effectively looking through. Different combinations of front and back surface powers produce varying degrees of optical aberrations, and a particular base curve is selected which minimizes these aberrations for a given lens material and back vertex power. So a base 2 means the front surface has a 2.00 diopter base curve, which translates to a radius of curvature of 0.50mm.
 
Last edited:

faue

Senior Member
Joined
Dec 21, 2018
Messages
414
Reaction score
4,457
What are the trade-offs between polyamide and CR-39 lenses? I'm looking at sending a pair of JMM frames out to fit different lenses, and one of the 3 online services I've found uses polyamide (they're also in Australia, so that's a consideration)...
In short, CR39 has better optical quality, Polyamide trades off optical quality for being essentially indestructible.
 

JDelage

Senior Member
Joined
Oct 16, 2008
Messages
431
Reaction score
321
@faue - Thank you. So that number is not relevant for sunglasses with no correction, is it?
 

faue

Senior Member
Joined
Dec 21, 2018
Messages
414
Reaction score
4,457
@faue - Thank you. So that number is not relevant for sunglasses with no correction, is it?
You can still make a plano lens with a base curve, you’d just pick a rear lens power that neutralizes the front. It would be *approximately* -2.00, but depends on lens thickness and material, as well as frame type and size. Ex: if you had a base curve of 2 in a 3mm thick CR-39 lens, you’d have a back surface power of -2/(1-(.003)*2/(1.498) = -2.01 diopters.
 

faue

Senior Member
Joined
Dec 21, 2018
Messages
414
Reaction score
4,457
I understand what you tell me. I just wonder why sunglass makers would advertise base 2, base 4 on their models. See for example:
https://www.lunetteriegenerale.com/collections/sun/products/architect (base 2)
https://www.lunetteriegenerale.com/collections/sun/products/cognac-1 (base 4)

It doesn't seem that it's very relevant info...
It’s only relevant in this case if you have a high prescription — if they only offer one base curve, it means with higher prescriptions they won’t be able to pick a different one to compensate for aberrations.
 

JDelage

Senior Member
Joined
Oct 16, 2008
Messages
431
Reaction score
321
What are the pros and cons of Natives Sons vs Ahlem? Looking at one or the other for a pair of readers in acetate...
 

sartorialism

Distinguished Member
Joined
Jun 23, 2008
Messages
1,237
Reaction score
274
What brand are these? (They’re mine and I need to replace a nosepad; knowing the brand is step 1, I guess.) The model is Zephyr.
image.jpg
image.jpg
 

Attachments

  • image.jpg
    image.jpg
    190.8 KB · Views: 156

TheVirt

Senior Member
Joined
Apr 11, 2017
Messages
227
Reaction score
1,180
How are people usually storing their sunglasses when they go out? I wear regular prescription glasses so I'd have to be switching back and forth going indoors. A case is best to avoid damage, but I can imagine a case being kind of bulky to carry around without a bag of some sort.
 
Last edited:

Featured Sponsor

How important is full vs half canvas to you for heavier sport jackets?

  • Definitely full canvas only

    Votes: 85 37.6%
  • Half canvas is fine

    Votes: 86 38.1%
  • Really don't care

    Votes: 24 10.6%
  • Depends on fabric

    Votes: 35 15.5%
  • Depends on price

    Votes: 36 15.9%

Forum statistics

Threads
506,436
Messages
10,589,301
Members
224,231
Latest member
Vintage Shades
Top