[gazonk]

These are my reasons too. I really want that 15 Limited, 20-40 Limted and the 55-300 combination. It is an amazing focal lenght range unthinkable at 900grams a few years back.

For my daily casual photography (on my way to work etc.), I usually find the DA15 Ltd / DA35 Ltd / DA55-300 combo a little too heavy. 15+35+70 is lighter and also covers quite a bit, especially with the possibility of cropping that the sharp DA70 gives on the K-5. Could I use faster lenses? The 70 covers most of the need for shallow DoF (portraits etc.) and with the f/2.8 macro I more often than not stop it down. With the DA15 I can easily shoot handheld at 1/4 second, so the need for anything faster is really rare (The only times I've missed a really fast wide in that range is when shooting wide views of the night sky). Sometimes I also put my M-50/1.7 in my bag and have the need for really thin DoF covered with that lens.

[Aristophanes]

A Ferrari is about performance. Performance in a lens is about optical quality which has nothing to do do with lens speed. A fast lens should be compared to a truck.

Sometimes I think fast glass is about selling insecurity, preying on those who want to take better photos and based on hearsay they are told and then believe that f/1.8 is "better" than f/3.5.

Then you look at almost all their photos and realize they shot 90% of them at f/5.6 or smaller aperture

And the ones they shot at 1.4 all have that same OOF aesthetic which...everyone has when they shoot at f/1.4. A common critique I have of a lot of portraits, mostly casual...a good pro know better, is too shallow DOF. The should have stopped down more, not less.

High ISO has done far more to "get the shot" than fast glass.

I'm not saying the Sigma is a bad lens; I am saying it is as niche as a Fast 50. Its size alone makes it a marginal product in today's overall market. I reiterate that what makes the lens feasible at all is that Sigma can cross brands to get a reasonable volume. Without that, this lens would not exist as a single proprietary brand could not sell enough.

[ChristianRock]

A Ferrari is about performance. Performance in a lens is about optical quality which has nothing to do do with lens speed. A fast lens should be compared to a truck.

Well, everybody has their point of view. In some ranges - and that's just my opinion - (normal/telephoto) fast glass is all about performance. The exception is wide angle, but even there, fast glass has its advantages (indoors, night, etc) and when stopped down, usually performs at the level of slower glass, if not better.

[redrockcoulee]

For my daily casual photography (on my way to work etc.), I usually find the DA15 Ltd / DA35 Ltd / DA55-300 combo a little too heavy. 15+35+70 is lighter and also covers quite a bit, especially with the possibility of cropping that the sharp DA70 gives on the K-5. Could I use faster lenses? The 70 covers most of the need for shallow DoF (portraits etc.) and with the f/2.8 macro I more often than not stop it down. With the DA15 I can easily shoot handheld at 1/4 second, so the need for anything faster is really rare (The only times I've missed a really fast wide in that range is when shooting wide views of the night sky). Sometimes I also put my M-50/1.7 in my bag and have the need for really thin DoF covered with that lens.

Whenever I ever get my 15DA my light kit will be the K-r 15DA, 35 2.4 DA and the 70DA with a Lowe Pro compact camera case that is big enough to hold any two of those lenses. Currently I use the FE17-28 instead of the 15DA. I use to take the F50 1.7 until I got the 70DA

Later this month I will be shooting an indoor rodeo where the light is low but harsh. Still thinking of perhaps borrowing a 200 2.0 and using a monopod. There are times for speed and times for lightness. Even the DA limiteds are faster than any of my LF lenses and certainly faster than our pinhole lenses. Try f322 at ISO 6

[gazonk]

Whenever I ever get my 15DA my light kit will be the K-r 15DA, 35 2.4 DA and the 70DA with a Lowe Pro compact camera case that is big enough to hold any two of those lenses.

Great :-) I think I'll stick to the 35 Ltd myself, not because I don't like the 35/2.4 (I've used it and love it), but because I like to have the ability to do extreme close-ups. For occasional flower shots or similar, the DA15 is actually pretty good too . The DA70 not so, I wish it had a slightly shorter minimum focusing distance.

[northcoastgreg]

The consensus is that you get the f/4 if you can't afford the f/2.8. Canon shooters seem very concerned with status and perception - I'm not saying this is right, as the f4 lenses can deliver results that sometimes are just as good, and they're much more portable - well, to me they're still huge... I'm sure there are exceptions that value portability over speed. But most people want the fast glass. Kind of like most people who want to be considered "pros" want the full frame sensor

I suspect that's the truth. I'm surprised how often I run across landscape photographers shooting f2.8 zooms with FF cameras. I've literally run across 100s of photographers at iconic landscape locations such as Oxbow Bend and Maroon Bells, and I'd say about half the photographers I see using standard zooms with FF camera are shooting one of the Canikon f2.8 24-70s. The f4 zooms that seem more popular are UWA and the Canon 70-200 f4. The bias for f2.8 is particularly strong on the Nikon side. I've never run across the 24-120 f4 in the wild, and the Nikkor 14-24 f2.8 has a legendary reputation among landscape photographers.

What gets me is the massive weight of the thing at a time when all market activity is pointing to smaller and lighter driving the bulk of sales both in bodies and lenses.

While there's definitely a drive for smaller stuff, among photo enthusiasts there exists a mania for hand-hold shooting in low light, which is driving even Fuji and Olympus into making lenses that would appear too big for their small cameras. Olympus is planning to release a 40-150 f2.8 and a 300 f4 in the next year or so. Those lenses will probably weigh around 2 lbs. The Olympus 12-40 f2.8 is about 50% heavier than the DA 20-40. Fuji has several f2.8 zooms on their roadmap, and Samsung is releasing a 16-50 f2-2.8 which is more than twice as heavy as the DA 20-40.

[Rondec]

I am glad that this lens is going to be coming to K Mount eventually, but I really don't expect it to make a huge splash. Pentaxians are really drawn to the small size of Pentax glass and they are pretty willing to trade speed for size, hence the DA limiteds. Pentax does have f2.8 zooms, but honestly they don't have any particular benefit over Canon/Nikon similar zooms.

For many purposes, speed is not crucial, while small size is awfully handy.

[Parallax]

Pentax does have f2.8 zooms, but honestly they don't have any particular benefit over Canon/Nikon similar zooms.

The Pentax f2.8 zooms have one huge advantage over the Canon/Nikon zooms. They work on Pentax cameras.

[vjacesslav]

What a beautiful combo it could be:
SIGMA 18-35mm 1.8
PENTAX 50-135mm 2.8
Unles Sigma brings something more competitive to Pentax 50-135mm

[ChristianRock]

I agree with the points you guys make, but the reality is this: if Ricoh wants to increase Pentax share market, they have to offer something to the "well-to-do enthusiast" as I call them. That's the people with more money than sense. I know a few of those, and they are the ones spending money and keeping Canikon in business! They are the ones with more money invested than most of us, and they are out there taking landscape pictures with their 2.8 zooms on Auto mode, hand held, with their hoods on backwards.
If these people want an APS-C camera, they'll be delighted with the Sigma 18-35. And guess what, it will take great pictures even at 1.8 (from what I've seen it's sharp wide open) and they'll be happy.
The problem is that the "well-to-do" are not happy with APS-C anymore. That's for soccer moms now. But I digress...
The good photographers and the professionals I know are making great images with equipment they bought 5, 10 years ago. They don't upgrade all that often, from what I can see. And much of what they invested, was invested in light and modifiers... and I do see them using APS-C cameras.

[seventysixersfan]

What a beautiful combo it could be: SIGMA 18-35mm 1.8 PENTAX 50-135mm 2.8 Unles Sigma brings something more competitive to Pentax 50-135mm

But they had done so, only it's discontinued. My Sigma 50-150 f/2.8 HSM is awesome and other than the lack of weather sealing, at least the equal of the DA 50-135 if not even a bit better in some cases (like autofocus speed).

I can't wait to pair up a Sigma 18-35 with my Sigma 50-150. That's a lot of weight in my camera bag but boy the image quality will be spectacular!

[vjacesslav]

Yes i can agree that Sigma has some advantages over the Pentax 50-135... Similar filter size 67mm, longer than Pentax, and one huge advantage is compactness... It is really nice compact kit with Pentax K-5 I´ve had one... But unfortunately has to go... I think Sigma will Brink update here too, new versions in Canon and Nikon si even better than older one

[VoiceOfReason]

I'm not saying the Sigma is a bad lens; I am saying it is as niche as a Fast 50. Its size alone makes it a marginal product in today's overall market. I reiterate that what makes the lens feasible at all is that Sigma can cross brands to get a reasonable volume. Without that, this lens would not exist as a single proprietary brand could not sell enough.

It is aimed squarely at me for my convention photography. I shoot pretty much exclusively between 20-30mm and as wide open as I can get away with because the lighting is crap, flash photography isn't my strength, and I try to avoid using ISO over 3200, lower is better because I want the dynamic range for the costumes, and I want sharp pics with less noise, and I want to try to isolate my subject as much as possible. I doubt I would be using it for hiking or landscape stuff when I get it.

[ElJamoquio]

I suspect that's the truth. I'm surprised how often I run across landscape photographers shooting f2.8 zooms with FF cameras.

Meh.

The reality is that the F/2.8 zooms in Nikon are better than the slower lenses, by and large, even when stopped down.

Personally it'd be tough for me to justify both. Right now I have a 24-85 F/3.5-4.5 and I'm thinking I'll keep that and put the 14-24 f/2.8 under that. The Nikon 14-24 weighs twice as much as the Sigma 8-16 (Pentax) that I have but that Sigma leaves some IQ to be desired. The Sigma FF 12-24 is actually not incredibly good either. I'd really like a 12mm (or 8mm on APS-C). I feel like I'm compromising already at 14mm; 16mm is out of the question.... so it's the 14-24mm or nothing.

Would I prefer a 12-24 F/4? Sure, but it doesn't exist. At least the 14-24 should be fun for some astro stuff.

[Mock]

Now people who want f/2.8 zooms are well-to-do, with more money than sense, and most likely poor photographers shooting in auto with the hood reversed...what.a gross generalization, as if there is no compelling reasons for a photographer to actually own such a lens.

I looked into sales data of our company, the Canon 70-200 f/2.8 varieties outsell the f/4 varieties 3:1.
Among the f/2.8 lenses I've personally sold, most were to pro or serious-amateur photographers, people who know what they are doing and know their requirements in a lens. This idea floating around that a fast zoom is impractical like a muscle car is baseless. True, there are a few people who buy such lenses just for social status, but they are a minority - they aren't "keeping Canikon in business".

Some people choose fast zooms, some choose compact prime lineups, some people don't mind cranking the ISO with slow lenses. As long as they are happy with the results and know how to get the most out of their gear, none of them should be disparaged as if their choice makes them a poor photographer.