[Nicolas06]

And when does the patents expire? Canon introduced the eye tracking feature in EOS 5, about 24 years ago.

A patent is valid for 20 years. One would have to check the actual patents they have, what they say, and when they have been granted.

Also a big thing in patent is that you don't have necessarily all patents and everybody is free to add patents on top on your own, as an improvment or combination. So typically if Pentax was greatly improving the feature with a new technical process (what a patent is about) they could patent that and if that's really interresting they could negociate with Canon to grant each other the rights to use their relative patents on the subject. It is likely Pentax could provide the same feature but do it quite differently and that would mean new, different patents and the possibility to do things for themselves without being sued by Canon.

[Bophoto]

So the new and coming DFA lenses as the K1 are big thing, and APS are lesser and light.
But we have the 3 limited lenses and perhaps it coming new limited as 21/4, 100/135/3,5 and a mirror 350-500mm before 2018-19.
One scenario are if they renewed lenses as FA35/2 and FA50/1,4 or 1,7 with WR and HD. It´s easy and they are small, can be a mix of new and renewed lenses.

[Simen1]

But we have the 3 limited lenses and perhaps it coming new limited as 21/4, 100/135/3,5 and a mirror 350-500mm before 2018-19.

I would love more small FF limiteds! Buying a larger and heavier camera means that I will compensate by prioritize smaller and lighter lenses. Since the weight problem is most prominent in the tele end, the mirror lens is absolutely not a bad idea. A 600 gram 400mm f/4 WR would be excellent.

[RobA_Oz]

The FA*24/2 is pretty lightweight (some say also in performance, but I'd say not for all purposes) and not expensive, unlike the FA*28-70/2.8 and the FA*80-200/2.8, on both counts. When I do get a K-1, I expect to use all three, but the 24 will be more likely on the body when it's hanging around my neck. The existing FA Limiteds are light, although the 31 is heaviest, and the FA20/2.8 is around secondhand if you don't mind a used legacy lens. They could do worse than reviving the 24/2 and the 20/2.8, even without SDM/DC AF drives and WR.

[thibs]

A mirror lens would be a very bad idea.

[RobA_Oz]

A mirror lens would be a very bad idea.

You don't like doughnuts?

[timautin]

A mirror lens would be a very bad idea.

+1. Lightweight is important, but less than IQ imho... For the 500-600 range, I'd prefer to carry a 3-5 kg lens, with great IQ, than a 600g one which produce bad pictures.

[Barry Pearson]

A mirror lens would be a very bad idea.

The mirror lenses I'm aware of tend to have poor IQ. But is that a necessary consequence of being a mirror lens, or simply because they tend not to be designed for the highest image quality?

I suspect that, except for the doughnut-shaped out of focus parts of the image, it would be possible to design a mirror lens with high image quality, at a price.

There are some very big very high quality mirror-based optical systems on the planet (and off it)!

[D1N0]

There are some very big very high quality mirror-based optical systems on the planet (and off it)!

But those aren't very light

[Simen1]

A mirror lens would be a very bad idea.

For the bokeh club, yes. For us BoB shooters (Bird on Branch) we often find uniform blu sky behind our subjects.

+1. Lightweight is important, but less than IQ imho... For the 500-600 range, I'd prefer to carry a 3-5 kg lens, with great IQ, than a 600g one which produce bad pictures.

You already have lots of nice options that should fit. I don't. Carrying a 3+ kg lens is not an option. Buying one is not an option eater. Yes, I must pay more attention to the background, but I'm willing to pay that price for saving a pile of money, back pains and a hard argument with my wife. I will go through enough just to buy the K-1.

All mirror lenses I have seen and read about to date is low quality usually designs from three decades ago without a hood. A large hood and internal baffles are important to increase contrast. The blackness and rib shapes on baffles and hood are important too. I know of only one mirror design with AF and that is only in Sony alpha mount. I have seen a couple of mirror lenses with a built in ND filter wheel to control the amount of light as an alternative to having a variable aperture, but none with hood or AF. I have seen custom made mirror lens designs with an asymmetric design (no doughnut), but never one with a camera mount. I'm sure that If Pentax wanted to make a modern mirror lens according to the digital age and high demands, they could make a mirror lens that could change the principle view on them and virtually put a low quality tag on all the rest. A mirror lens is not a bad idea, its just historically poorly conducted.

But those aren't very light

They are extremely light .. like in photonic light, for their focal lengths.

[ogl]

The FA*24/2 is pretty lightweight.

Rather heavy lens. 405 gram. the same weight as DA18-135

[D1N0]

They are extremely light .. like in photonic light, for their focal length

OK send me one giant Magellan in the mail please

[mee]

Monochromes law: As an online discussion of pentax camera gear grows longer, the probability of a comparison involving SONY Approaches 1.

hmm, sounds a bit restrictive as It only mentions SONY, there are other camera manufacturers out there.

There were other horrific, totalitarian regimes out there too.. but the one mentioned was the largest and most known..

[Simen1]

@D1N0 If you send me a similar specified refractive lens in return, we have an exchange deal.

[D1N0]

@D1N0 If you send me a similar specified refractive lens in return, we have an exchange deal.

I'll try to hack Hubble and make it land in your Yard.