[JimmyDranox]

Because 135-380mm is not an 80-400mm. One is 2.8x zoom, the other is 5x zoom. And, some times ago, Sigma made cheap lenses, but not as good as Nikon or Canon, or Pentax. Now things seems to change, in Sigma's favor, with lenses both cheaper and better.

By the way, zoom 135-380mm looks like a range for a lens with a constant aperture. Maybe f4?

[ElJamoquio]

Because 135-380mm is not an 80-400mm. One is 2.8x zoom, the other is 5x zoom. And, some times ago, Sigma made cheap lenses, but not as good as Nikon or Canon, or Pentax. Now things seems to change, in Sigma's favor, with lenses both cheaper and better.

By the way, zoom 135-380mm looks like a range for a lens with a constant aperture. Maybe f4?

135-380 F/4 would be a $10k lens from Pentax. That would not likely be a good seller.

[woodywesty]

135-380 F/4 would be a $10k lens from Pentax. That would not likely be a good seller.

I guess I just don't see why it would follow that a Pentax 135-380 F4 would $10k or even $5k when a Pentax 60-250 F4 only costs $1,400. I could see a 135-380 F4 costing 2K or maybe $2,400.... But I think that what earlier posters have stated that the new lens is going to be a match for the DA18-135 with similar optical qualities. That being the case it wouldn't be as good an option for birding as the Sigma lenses.

[ElJamoquio]

I guess I just don't see why it would follow that a Pentax 135-380 F4 would $10k or even $5k when a Pentax 60-250 F4 only costs $1,400. I could see a 135-380 F4 costing 2K or maybe $2,400.... But I think that what earlier posters have stated that the new lens is going to be a match for the DA18-135 with similar optical qualities. That being the case it wouldn't be as good an option for birding as the Sigma lenses.

Pentax lens prices are 10-20% more than Canon/Nikon (more in the case of the limiteds, and deservedly so). Canon's 200-400 f/4 is $11-12k. I had forgotten that that lens has the integral T/C (is that the one?). Let me retract my previous comment, and say that the Nikon is $6500 so I guess the Pentax could be $6k.

[zokes83]

Because a Canon 200-400/4 costs 12k € and a Nikon 200-400/4 7k €.

[Giklab]

Nikon's 200-400 f/4 is, what, 7-8k? and Canon's new 200-400 with built in extender is somewhere upwards of 14k.

Edit: As pointed out above

[Mistral75]

I guess I just don't see why it would follow that a Pentax 135-380 F4 would $10k or even $5k when a Pentax 60-250 F4 only costs $1,400
(...)(

Because a 135-380mm f/4 means a 10cm front lens when the one in DA* 60-250 is around 63mm in diameter and Δ price is approximately (Δ diameter of front lens) ^ 3.

[rjm623]

I for one would love to see a megapixel bump on their midrange cameras. I know that MP count isn't everything, and the 16 mp sensors on the K50/500 are excellent, but with the competition moving past 20+ mps, they need this upgrade.

[woodywesty]

Because a Canon 200-400/4 costs 12k € and a Nikon 200-400/4 7k €.

Are the Canon and Nikon lenses for full frame or cropped camera bodies? Would there be a difference in the cost to build between the two of any significance? In any event I starting to see that my options are heading toward Sigma as long as they keep supporting the K mount.

[Mistral75]

Are the Canon and Nikon lenses for full frame or cropped camera bodies? Would there be a difference in the cost to build between the two of any significance? In any event I starting to see that my options are heading toward Sigma as long as they keep supporting the K mount.

They are for 24x36 cameras but, for such long lenses, the difference in the cost to build is marginal.

[VoiceOfReason]

I figure a 135-380 lens would be a variable aperture and a weather sealed companion to the 18-135. Maybe f/4-6.3 and hopefully less than 1,000. Of course with Pentax pricing...

[RonHendriks1966]

I figure a 135-380 lens would be a variable aperture and a weather sealed companion to the 18-135. Maybe f/4-6.3 and hopefully less than 1,000. Of course with Pentax pricing...

If you want it under $1000 then you probably get f5-f6.3 or so.

[VoiceOfReason]

If you want it under $1000 then you probably get f5-f6.3 or so.

I could still deal with that. It would be pretty much exclusively outdoor use for me. I already have a long lens, but one with sealing when I am in the desert or with threatening weather would be great.

[JimmyDranox]

Those lenses are extremely expensive for other reasons that manufacturing cost. For example, a refractor telescope, with 3elements of 10cm aperture, and extra low dispertion glass, FPL 53, the best on the market, cost about 1500-1800 euro, retail. The best flat field corrector for FF is 600 euro, retail. The rest of elements, and construction, necessary for an AF, could cost maybe 1000-2000 euro, retail. Why such a big difference? Don't know for sure.

[ElJamoquio]

Those lenses are extremely expensive for other reasons that manufacturing cost. For example, a refractor telescope, with 3elements of 10cm aperture, and extra low dispertion glass, FPL 53, the best on the market, cost about 1500-1800 euro, retail. The best flat field corrector for FF is 600 euro, retail. The rest of elements, and construction, necessary for an AF, could cost maybe 1000-2000 euro, retail. Why such a big difference? Don't know for sure.

Hence the conundrum around the 560 f/5.6.

It doesn't have that many elements (like a telescope), doesn't focus very close (still closer than a telescope, generally), etc. Yet it's $7k.

In terms of 'real' telephoto lenses there's a lot more elements, more correction, etc, in camera lenses than in telescopes.