[northcoastgreg]

I've tried both the 18-135 as well as the 16-85 and I obviously had no choice but to compare them against what I feel as my own standard (not fair, I know, but still). I would expect that even with a move from 16Mp (K-5 IIs) to 24Mp (K-3) more of my lenses would disappoint and I'd lean even more towards using my two best pieces to extract all I could from the body. I can't even imagine how disappointed I'd be with using the equivalent of the 16-85 on the K-1's monstrously detailed and sharp 36Mp sensor - the camera deserves more than that and therefore it deserves more than a mediocre 28-105.

Assuming that the 16-85 is sharp enough to take advantage of the 16 MP sensor in the K-5iis (and I believe that's a pretty safe assumption), then there should be no issues with a lenses as sharp as the 16-85 on the K-1 (as the K-1's sensor has comparable pixel density to the K-5iis). I understand and sympathize with the desire to use the very best glass on the FF. And Pentax has provided that with their f2.8 trio. But that doesn't mean there isn't room for a decent standard zoom lens that doesn't cost north of $1,000.

The rest of the D-FA lenses look to be a blast and I just cannot figure out the 28-105's raison d'etre.

Once Pentax decided to market their FF for $1,800, they had to include an economy kit lens. It's just good business. Without a cheaper option, Pentax would likely lose sails to price sensitive buyers due to the cost of those f2.8 zooms.

You still gain 1 stop of light, but that would have been true too with a 17-70 f/2.8-4, counting the FF sensors tend to perform even better at low iso, you may even be almost at the level of a 17-30 f/2.8-3.2

That's all true, but I was thinking more of those who are interested in the K-1 and the DFA 28-105 to use for landscape photography, where ISO performance plays little if any role and where the advantage of FF is primarily the added resolution. People buying the K-1 for landscape photography have three major options if they wish to use a Pentax standard zoom: legacy film lens, the DFA 24-70 f2.8., and the DFA 28-105. I think some people are wondering whether the DFA 28-105, which is nearly half the cost and half the weight of the DFA 24-70, might be an adequate substitute for the DFA 24-70 f2.8 for landscapes. After all, you don't need f2.8 for landscapes.

[jatrax]

I think some people are wondering whether the DFA 28-105, which is nearly half the cost and half the weight of the DFA 24-70, might be an adequate substitute for the DFA 24-70 f2.8 for landscapes. After all, you don't need f2.8 for landscapes.

Precisely. The 28-105 would also make a much nicer walk about lens than the 24-70 monster.

[robjmitchell]

The rest of the D-FA lenses look to be a blast and I just cannot figure out the 28-105's raison d'etre.

The 28-105 is there principally there as coverage for existing Pentax users who already have a selection of FF prime lenses but don't have the means or desire to own large expensive 2.8 zooms. I used to pack a sigma 17-70 for just that purpose. Use primes when IQ is top concern, zoom when convenience is desired.
It would be great if the 28-105 is sharp in the corners at the wide end at f8.

[clackers]

The rest of the D-FA lenses look to be a blast and I just cannot figure out the 28-105's raison d'etre.

"Kit lens." ☺

[normhead]

Norm, on my K-5 IIs my sharpest lenses are the DA*50-135 and the Sigma85mm. I do use other lenses when range or situation require such. I do use the Tamron 17-50 and Pentax 55-300 quite a bit and I like them a lot but they don't even come close the the first two and I accept that fact.

I've tried both the 18-135 as well as the 16-85 and I obviously had no choice but to compare them against what I feel as my own standard (not fair, I know, but still). I would expect that even with a move from 16Mp (K-5 IIs) to 24Mp (K-3) more of my lenses would disappoint and I'd lean even more towards using my two best pieces to extract all I could from the body. I can't even imagine how disappointed I'd be with using the equivalent of the 16-85 on the K-1's monstrously detailed and sharp 36Mp sensor - the camera deserves more than that and therefore it deserves more than a mediocre 28-105.

If I'd be buying the K-1, I'd make sure the quality of my optics keeps tred with that of the resolving power of my new sensor, heck I'd even do that with the new APS-C body (more realistic in my case). It is just a case of ensuring expectations are borne out and Pentax can certainly do without the initial rash of "it's not so sharp as I expected" blogposts.

The rest of the D-FA lenses look to be a blast and I just cannot figure out the 28-105's raison d'etre.

Most of us don't use a walk around lens because they are the best possible optics. We use them because much of the time, the lens on your camera is the one you're going to use, and you're going to miss shots if you don't have the zoom range. I don't mind changing for wide glass, landscape doesn't run away on you. There are times when the long end of a walk around is indispensable.

As Clint Eastwood said in the Unforgiven, "deserve has nothing to do with it". But I agree, not holding the images until they had something lights out, is just hard to understand.

[timb64]

Did I miss something?
Oh just Norm getting all over defensive because someone alluded to his pet as less than the be-all-and-end-all.Want some salt and vinegar with that chip Norm

[DeadJohn]

Go to the user control panel, on the left side select "Edit ignored users" ad the person you wish to ignore... anyone i know?

I hope it's you. Not because of anything you said, just the humor in helping someone ignore you. If only that worked at home sometimes

[yorik]

I agree. In fact, when the 28-105 is matched up with a 36 MP FF sensor, it will likely be a little better than 16-85, thanks to the extra MP and the larger sensor. The only question is: if it is only a little better, will that be enough to justify moving to a larger, more expensive camera?

The larger, more expensive camera will allow me to use the three amigos at their intended fields of view (with a tilty screen to boot ). At that (distant, saved-enough-money) point in time, I will also probably get the 28-105 to have the WR zoom for beach days, and fall hikes, etc. When I bought my K5 (4 years ago), I had intended to get the 18-135 kit, but didn't because of some of the reviews I read. I frequently regret that decision - from what I have seen others on this forum do with it, it seems to me to be a great lens for its intended purposes (and price point).

[Nicolas06]

"Kit lens." ☺

+1 ! The obvious raison d'être of this 28-105 is to be a kit lens. Like most kit lens it is sold for a very low price bundled with cameras. A camera alone has no value. You need at least 1 lens to use it and you may not have much money to spend on it at the begining.

The 28-105 will likely outsell all the other recently introduced DFA lenses by a huge factor, maybe 10 time. Simply because you'll get it for maybe 300$ with the body, that it is still Wr, sharp and quite good performer, because it is reasonnably small and still will make great photos.

People complain at 36MP the lens could be sharper but what this lens does is still enough for 30x40" prints and for a low price. pentax has only 1 FF with 36MP so you get that one even if you want FF for other reasons.

The FF still expensive, but likely in 2-3 year it will be half the price too...

This make lot of sense, it just doesn't fit everybody needs and it doesn't have to.

[Rondec]

"Kit lens." ☺

Exactly. It seems unlikely to me that Pentax would bundle the 24-70 f2.8 with the K-1 and give a discount, while with a kit lens, buying the lens with the camera often gives 100 dollars off or something like that. My expectation is that a lot of folks will buy a K-1 to shoot their existent lenses -- probably mostly older primes -- but still would want a modern (but not too expensive) lens to mount when they are just walking around town.

[timb64]

I hope it's you. Not because of anything you said, just the humor in helping someone ignore you. If only that worked at home sometimes

Norm doesn't do irony

[normhead]

I hope it's you. Not because of anything you said, just the humor in helping someone ignore you. If only that worked at home sometimes

Oh I'm sure it was me... that's half of what made it so funny.

I laugh around here a lot more than people think I do.

[One3rdEV]

I share the perspective of the many others here who have expressed absolutely no worry about Pentax offering this 28-105 mm option. And for the very same reasons; convenience in size, weight, focal length range, and weather proofing (to accompany its relatively low cost).

For example: I purchased the Sigma DC EX 17-50 f2.8 with my K-5 back in 2012. It was relatively new to market and in Nikon mount the highest performing resolution in DXO's stats of any zoom (or nearly any lens listed for that matter, if I recall correctly) at that time. I later purchased the Pentax 18-135mm in 2014 for its WR. The 18-135mm produces really nice photos - as long as you don't compare them side-by-side to the aforementioned Sigma. But I find the convenience of the 18-135mm to be greater than the Sigma for a lot of general use. Since most of my photography opportunities are associated with family activities these days- guess which lens gets all of the use? The convenience lens.

For professional use, the other newly introduced F2.8 lenses are available for those who need / want them. If I were shooting for commercial purposes like back in my film days- then these would be the lenses I would choose. But then again… if I had ever been a real professional with established acclaim - then it wouldn't particularly matter what equipment I chose to use, because it would have been my personalized style that really mattered.