[Blue]

Is there anyone here with enough technical knowledge or research to explain the costs and technical hurdles involved in fast lenses?

For example, an f0.95, f1.2, and f1.4 in say 35mm... What makes them cost so much?
f-number = focal length / diameter of the entrance pupil.

35mm / 30mm = Around a f1.2 lens. A 30mm diameter front lens element doesn't really sound large. Is it really the cost of the glass or something else?

I started skimming through tutorials online about how to make your own lenses and one mentioned a single element lens that was around f0.95 that was just basically a cheap piece of glass placed in front of the lens mount. With some correction the results looks pretty decent. Well technically it was stopped down to f4 with a piece of cardboard.

It seems like a fascinating subject and I'd like to try my luck at it someday. I wonder what computer software the professionals use in the design process?

There are a few people here that have the technical expertise. Falconeye is one. The R&D on fast lenses isn't cheap which is why I keep mentioning past production lenses and prototypes as a basis to start.

[RossCo]

I don't think that a super fast lens should be a priority. I would favour the development or reissue of some of the long lenses that have been available in the past. I am currently looking for a 400+ mm lens for wildlife so a 31/50mm F0.9 lens is no good to me.

I noticed a survey from a couple of years ago asking about the need for a teleconverter and what did Pentax do - they came out with a GPS for the K5. I thought this was a poor response to the need for a teleconverter.

Paul
K7,
DA*16-50, DA*60-25
645
SMC A 75 F2.8, SMC A 150

[Blue]

I don't think that a super fast lens should be a priority. I would favour the development or reissue of some of the long lenses that have been available in the past. I am currently looking for a 400+ mm lens for wildlife so a 31/50mm F0.9 lens is no good to me.

I noticed a survey from a couple of years ago asking about the need for a teleconverter and what did Pentax do - they came out with a GPS for the K5. I thought this was a poor response to the need for a teleconverter.

Paul
K7,
DA*16-50, DA*60-25
645
SMC A 75 F2.8, SMC A 150

By the time that goofy gps thing that takes up the shoe comes out, there will be plenty of apps for iPhones and androids, . . . oh wait, there is.

[sjwaldron]

There are a few people here that have the technical expertise. Falconeye is one. The R&D on fast lenses isn't cheap which is why I keep mentioning past production lenses and prototypes as a basis to start.

I agree. I think the D-FA 100mm f2.8 WR Macro is a great example of using an older design to re-release it with new features that define Pentax (solid metal limited style casing and WR). My only gripe is it should have a focus limiter (two generations back?) because the lens is spectacular for portraits.

I'd be interested in seeing some of the older glass tested for resolution with a K-5 to see how they stack up against newer designs. When I use the DA* 55mm, sometimes I get a little shocked by the resulting photos (compared to say the FA 50 I use to have), so I can also appreciate new digital centric designs.

Besides that, I'm wondering if sourcing of glass is an issue in releasing older designs. Although, I would think Hoya would be the perfect company to make fast lenses happen with their experience plus the Pentax branch.

Optical Glass and Lens Pressings from HOYA OPTICS: Leading supplier of advanced optical materials & components

Pentax/hoya in my mind seems like the perfect company to make a wide selection of special limited production lenses. They already do it with the FA and DA limiteds. They even do it with their completely customizable color K-x/K-r camera bodies in the Japanese market. I think the FA limited demonstrate that people are willing to pay a fair price for special high quality lenses.

[rvannatta]

I"m quite satisfied with primes in the F/1.4 and F2 range. A prime is hardly worthwhile
if it's no faster than a credible zoom, but similarly there is no reason to go over the edge
with fast optics with the ISO trends are rising.