Some of the contributors here are particular about German vs Canadian glass on their lenses. How particular are you about the glasses you wear?

Your glasses are your primary optics for viewing all pictures, scenes and life in general. I have had one pair of plastic lenses in 30 years, and never again. The definition and color are "terrible". Have any others on this forum noticed a difference?

What differences besides weight?

;)

-- Mark A. Johnson (logical1@catholic.org), March 04, 2002

Answers

I've had a pair of Zeiss glass once. In a word, great. But as my eye sight deteriorates the glass got heavy and that gives me severe discomfort, so i opted for plastics nowadays. Need to be comfortable before i can even function, much less take photographs:) Interesting thread.

-- Steven Fong (steven@ima.org.sg), March 04, 2002.

Here's a post from Richard Clompus OD who posted it to the LUG. It's a bit off topic but interesting.

"As in camera optics, much as changed with the optics used in spectacle lenses. When you reach age 40 or more, the eyes have lost some of their ability to focus close. Its as if we are all born with built in "macro lenses" that become more like "non-macro lenses" after age 40.

Bifocals (lens with distance and near optics) have been available since Benjamin Franklin. He actually invented them. The problem is our lifestyle and visual requirements have continued to change. We need help in focusing at distance, intermediate (arms length) and at near for reading. A trifocal lens can be used for this but is often heavier and you now have three segements to deal with.

A progressive lens is more like a zoom lens that focusses smoothly from distance to near by lifting your chin so that you view through lower areas of the lens. The optics have improved considerably in the past five years.

In optics there is no free lunch. The lens designer has to provide a wide enough channel to view at the intermediate and near distances. Aberrations are pushed peripherally - that include induced astigmatism. Fortunately, the eight pound mass that sits on our shoulders (brain) has a trmendous ability to process visual information. Almost a third of it is dedicated for this purpose. The brain uses the information and tends to suppress the distortion. After a week, many patients don't notice any peripheral distortion.

Each lens company believes they have made the best choices and compromises in their progressive design. Zeiss makes a Gradal progressive lens from Germany. Varilux makes a Comfort progressive lens from France. It was actually the French who came up with this design concept in the 1960's.

Most modern progressives work very well. Coupled with a UV 400 blocker and a five layer super anti-reflecive coating, they are marvels of optical design.

Some people can't adjust to progressives or even bifocals. I am sympathetic to them. Using these lenses is a great convenience. Most people do well when prescribed and fitted well. When measuring a patient for progressive lenses, you have a tolerance of only 0.5mm to line them up in the frame.

Finally, the size of the frame is often linked to fashion trends. Kind of reminds me of how men's ties go wide and then narrow and then wide again.

In optics, smaller is almost always better. The larger you go, the thicker the lens becomes and the more peripheral distortion you create. Smaller is thinnner, lighter and fewer distortions. You must have a minimal size for the optics to fit but Europe leads the way over America for optical design. Smaller is in for the moment.

Talk to your doctor and make sure if you don't adapt for any reason, they offer to remake your lenses into a visible bifocal at no additional charge."

Happy shooting,

Richard ----------------- Richard Clompus, OD West Chester, PA, USA

-- Bud (budcook@attglobal.net), March 04, 2002.

If I was in an accident with glass glasses and they shattered, blinding me, my career would be over. I'll take plastic, thanks, in spite of the definition and color (which I don't see, by the way-- maybe you should replace them more often than every 30 years.)

-- Michael Darnton (mdarnton@hotmail.com), March 04, 2002.

I have used plastic progressive lenses for 8 years (varilux, I think) and find that my visual accuity with them is excellent. I have not tried glass, but given my presription I would probably always be falling on my face from the weight of the lenses.

-- hearton (stevierose@yahoo.com), March 04, 2002.

I have no problem with plastic lenses, per se. I have had two pairs of glasses that gave me some problems with color and acuity. The first pair was made from flint glass, rather than crown, to cut down on the thickness of the lenses. I saw color fringing, mostly yellow; and things only looked sharp if I looked directly at them.

A pair made from polycarbonate (lexan) plastic was somewhat similar. I don't remember much of a problem with color fringing. They were just, well, hard to look through. Not comfortable. It was like the difference between looking through an $8.00 plastic loupe vs. a Schneider. Never went for them again.

-- Bob Fleischman (RFXMAIL@prodigy.net), March 04, 2002.

I used to have a Zeiss glass glasses but have in recent years changed to a progressive focus Hoya multic-coated plastic glasses. I can feel the difference, I can see things much better with the Zeiss glasses but the Hoya weights much less and progressive focus is more convenience. I have just ordered a progressive focus Zeiss glass glasses, not cheap though, cost me US$350. The sales person said a Zeiss progessive plastic glass weight much less and optically close the glass glass but cost US$450. I prefer to leave more money on the Leica lens.

-- tom tong (tom.tong@ckh.com.hk), March 04, 2002.

I had plastic lenses (Pentax) and after a couple of years they became so scratched and the coating wore off so much that I went back to glass which are sparklingly clear. The M3 metal eyepiece does not help as far as scratches are concerned - worse on plastic than glass. I still use plastic with clip-on sunglasses for playing tennis though, have another pair of plastic prescription sunglasses, and a prescription pair of goggles for swimming.

-- David Killick (dalex@inet.net.nz), March 05, 2002.

I have used both glass and plastic and prefer glass. However, glass breaks and that's just what happened to my Zeiss lenses--dropped onto my concrete garage floor. Zeiss lenses are expensive, about $350 for the lenses. IR for these lenses is 1.8, very high for glasses, but the result is that they are very thin. (I had to sign a safety waiver to purchase them.)

I have Titanium Calvin Kline frames for another $300, or $650 total, not including the exam.

You have to be pretty careful with these under virtually all circumstances. But it's worth it. My current pair, plastic, made by Hoya (IR=1.71) are lighter and nearly as thin and cheaper, but not by much ($300). However, I sometimes feel like I'm looking through a thin layer of milk. It's a lot like flare. I'm not sure if it's the lens itself or the coating, but they are not as clear as Zeiss.

By the way, I had my Zeiss for over two years without an incident. But it only takes once.

I had to consider what would have happened if my glasses broke while I was wearing them. My eyes and ears are precious. My eyes for photography and my ears for music. They are both critical for the hobbies I dearly love. I buy the best glasses I can for my eyes and keep safety in mind. I buy the most pleasing sounding music systems for my ears and avoid excessive noise and distortion.

Regards,

-- Mark Waideich (mark_waidelich@hotmail.com), March 05, 2002.

Fun question! I have Neostyle frames (German made excellent frames), and Sola Vizio lenses, which are plastic but have been optically computed to have virtually 0% distortion throughout the viewing field. VERY thin and the whole glasses are featherweight yet durable. Spring-loaded hinges too. Aintireflective coating, and scratch proofing, etc. The antireflective add so much saturation to viewing!

-- James (snodoggydogg@hotmail.com), March 05, 2002.

one of my best friends is a high end optitian, and he is always amused by the people that insist on buying zeiss lenses... yes, you should buy a good pair of lenses, but there is no difference between zeiss and other brands (except in price and that feeling people get oohhing and ahhing about their great lenses - kind of like leica users do =)

There are big differences in the coatings and frames though.

-- Matthew Geddert (geddert@yahoo.com), March 05, 2002.

The lenses in my glasses (which I wear all day) were made by Rodenstock in Regen (Southern Germany). They were the best quality and highest-priced lenses I could find. Not going to change anything here.

My older glasses' lenses were more plastic and softer and cheaper and much easier to scratch. But the glass I have today has never gotten any scratches, even when I smear my glasses up close along the viewfinder eyepiece (which is, yes, surrounded by a rubber framing) or up along my older 21A viewfinder eyepiece (which is, however, all metal).

Definition and color are absolutely neutral or "objective" here, much better than plastic. Glass lenses almost all consist basically of the same type of silica, whereas plastics vary much more considerably among themselves. Also, the glass lenses being so hard and stable means that they can also be made so much thinner than the older plastic ones. Therefore much lighter. Thickness however also depends on whether you need plus or minus dioptrine values.

For me, lens hardness is the most important parameter. I love my TTL, but it's not the only thing capable of scratching my glasses.

-- Michael Kastner (kastner@zedat.fu-berlin.de), March 05, 2002.

I am looking for new glasses too!

I have asked at several optical stores, but nobody has the newest multicoated Zeikon. They told me that I should wait for the aspherical lenses with the APO option. No doubt they will allow my eyes to see better. That means that I will understand what I see better, right?!

So, here is my question: Should I trade in all of my "old" autofocus glasses for the newest "manual focus" Zeikon? Are the German made lenses better than the older Canadian or Japanese versions? Will the newest lenses work as well on older frames or should I trade in for newer frames? I am undecided because I know that Canon is also coming out with new lines.

I am a beginner in this area and have a barrel full of money to spend and you lot seem like you know what you are talking about.

;-)

Man, I thought that Leica versus Zeiss was a technical debate!

-- Al Z. (alziari@aol.com), March 05, 2002.

I have one pair Zeiss glasses with Dunhill frame, the Zeiss glasses are heavy; I keep it home for reading. I bring along Fuji plastic glasses

-- martin tai (martin.tai@capcanada.com), March 05, 2002.

I've been wearing glasses for 35 years, and have yet to break glass ones. I tried plastic a few years ago, and, despite the alleged coatings etc, they quickly developed a nasty scratch haze right where I bring my left eye to a camera viewfinder. Never again! But finding glass is not easy, the McGlasses (as an ex-optometrist friend calls 'em) chains don't do glass and even the few remaining real opticians and optometrists are reluctant. With much hassle, I did find glass, in bifocals, and settled for plastic "computer glasses" as I'm not likely to do anything too destructive to them sitting in front of the CRT. Bifocals plus computer glasses = nice way of saying trifocals, ugh. My eyes were not made by Leitz....

-- Carey Russ (careyruss@earthlink.net), March 05, 2002.