[D1N0]

The 28-105 is basically the kit lens for the K-1 It is not unusual for kit lenses starting at 28mm (or 18mm for aps-c). A 24-105 would have been more expensive to make and it would compete with the 24-70 on focal length. I would expect the future to bring a 24-105 F4 but that could take a while. Maybe Pentax would introduce a D FA* 24-70 first, but that would have to out class the Tamron rebadge, which is pretty hard to do.

[normhead]

The 28-105 is basically the kit lens for the K-1 It is not unusual for kit lenses starting at 28mm (or 18mm for aps-c). A 24-105 would have been more expensive to make and it would compete with the 24-70 on focal length. I would expect the future to bring a 24-105 F4 but that could take a while. Maybe Pentax would introduce a D FA* 24-70 first, but that would have to out class the Tamron rebadge, which is pretty hard to do.

The more logical thing would be an 18-35 ƒ4. The equivalent of the 12-24. After all, why make a lens that's practically a duplicate of an existing lens when nothing exists wider?

Not to mention that the 28-105 is exponentially sharper than your average kit lens. There's a little bit of a disconnect in that statement.

[D1N0]

The more logical thing would be an 18-35 ƒ4. The equivalent of the 12-24.

That would be a strange lens for full frame. Ricoh better make the long predicted 12-28 extreme wide angle a D FA lens instead of DA. If they make it variable aperture and light enough it would serve wll on both FA and DA. Remember there is also a new fish eye zoom on the road map.

Not to mention that the 28-105 is exponentially sharper than your average kit lens. There's a little bit of a disconnect in that statement.

Is it really sharper than a 18-55 or 18-135 when used in crop mode or is the sharpness just due to the full frame format?

[normhead]

That would be a strange lens for full frame. Ricoh better make the long predicted 12-28 extreme wide angle a D FA lens instead of DA. If they make it variable aperture and light enough it would serve wll on both FA and DA. Remember there is also a new fish eye zoom on the road map.

Yet I have a FA-J full frame 18-35 ƒ4 to ƒ5.6. It's a terrible lens, but that doesn't mean they couldn't do it right. It's very light, if it was worth anything at all I'd take it everywhere. Anytime I get too happy, I just put it on the camera, take a few frames, look at them on the computer and that solves that.

Is it really sharper than a 18-55 or 18-135 when used in crop mode or is the sharpness just due to the full frame format?

It seems sharp enough to out resolve any sensor we've put it on, K-3 or K-5 or K-1, but I haven't tried it on the ultimate resolution tester, the Q.

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Last edited by normhead; 05-07-2017 at 01:30 PM.

[edin_togger]

That would be a strange lens for full frame. Ricoh better make the long predicted 12-28 extreme wide angle a D FA lens instead of DA. If they make it variable aperture and light enough it would serve wll on both FA and DA. Remember there is also a new fish eye zoom on the road map.

Why would an 18-35 be strange for full frame? Nikon make the excellent 18-35G which is an outstanding UWA lens.

[clackers]

Why would an 18-35 be strange for full frame? Nikon make the excellent 18-35G which is an outstanding UWA lens.

We've even had the Sigma 12-24 in K-mount previously.

[D1N0]

Why would an 18-35 be strange for full frame?

Because it is overlapping three other lenses and is not bringing anything extra, a 12-28 or 24 would give more wide end and would fit perfectly below one of those standard zooms.

[edin_togger]

Agree a 24mm of some kind is needed, it's shame Sigma aren't bringing the 24mm f1.4 Art to K mount.

[normhead]

Agree a 24mm of some kind is needed, it's shame Sigma aren't bringing the 24mm f1.4 Art to K mount.

I looked at that lens when it was announced and said
"Please bring this lens out in Pentax mount." under my breath 50 times, but it didn't work.

[pres589]

That would be a strange lens for full frame. Ricoh better make the long predicted 12-28 extreme wide angle a D FA lens instead of DA. If they make it variable aperture and light enough it would serve wll on both FA and DA. Remember there is also a new fish eye zoom on the road map.

A 12-28 full frame lens would be massive compared to a crop lens, same max aperture to same max aperture. I don't know that you'd want to tell a guy that he shouldn't expect something non-massive when there's the DA15 also sitting there on the shelf.

Something like an 18-35 f3.5-5.6 full frame might be really nice for crop guys as well, to take advantage of the center sharpness extending over more of his/her crop sensor's image circle. It would also give a nice wide angle option for folks that know they're going to give up some quality in the name of cost, weight, and size advantage. Seems like a nice product for someone that wants to shoot landscapes with their K-1 but doesn't want to buy or carry the 15-30 DFA.

[normhead]

A 12-28 full frame lens would be massive compared to a crop lens, same max aperture to same max aperture. I don't know that you'd want to tell a guy that he shouldn't expect something non-massive when there's the DA15 also sitting there on the shelf.

Something like an 18-35 f3.5-5.6 full frame might be really nice for crop guys as well, to take advantage of the center sharpness extending over more of his/her crop sensor's image circle. It would also give a nice wide angle option for folks that know they're going to give up some quality in the name of cost, weight, and size advantage. Seems like a nice product for someone that wants to shoot landscapes with their K-1 but doesn't want to buy or carry the 15-30 DFA.

The DFA 28-105 lens is about the same size as my 18-135, My FA-J 18-35 4-5.6 FF lens is one of the lightest lenses I own. There is absolutely no reason an 18-35 4-5.6 landscape lens couldn't be as light and high quality as any lens out there. Just going ƒ4 instead of ƒ2.8 cuts the weight in half just right there. The 28-105 doesn't give up anything to anybody, for IQ at 5.6 (APS-c) or ƒ8 on full frame. There's no reason an 18-35 couldn't be built the same way. Lots of LD and Aspherical elements, they don't have to be large.

My FA-J 18-35 4-5.6 weighs 218 grams with the front and back caps on it.. They could double the weight for improvements and still have a manageable lens. The 15-30 weighs 1040. Even doubling the weight of the FA-J 18-35, you'd still save 600 grams or a pound and a a third over a D FA 15-30. Anyone who loved the 12-24 on APS-c should be clamouring for an 18-35 ƒ4-5,6. The 12-24 is 418 grams... if anything a lens going to 18-35 mm should be smaller. Even if it appeals to only those of us who prefer the 28-105 over the 15-30 , 24-70, 70 -200 combo (two lenses to cover the range of one lens), even an 18-28 would be acceptable if the weight could be kept down.

Variable aperture doesn't mean lower image quality. It means more flexible design constraints, better (more efficient) use of the front element of the lens. They are cheaper in price, not necessarily in IQ. A fixed aperture zoom is by definition an inefficient use of the front element, for all but the longer focal lengths. At least with variable aperture, you get to use some of that front element on your wider angle images.

I rest my case.

[D1N0]

A 12-28 full frame lens would be massive

The Sigma 12-24 f4.5 5.6 is 600 grams and 87mm wide and 103mm long and Full frame. Sizable but not massive. It doesn't need to be an F4 constant zoom (but it does need to be better than that Sigma).

[monochrome]

It seems like a 24-105 would have been a more useful range than a 28-105 for the K1. Most manufactureres making a full-frame walk around lens usually start at 24mm as the few additional millimeters make a big difference when you are trying to capture the broad sweep of things. I hear great things about the 28-105 but it seems it would have been a real home run if it went to 24. I know that there are people out there who are perfectly satisfied with it and that's good. But, I have the 16-85 which I use on my crop sensor cams, and I would hate to give up the extra mm at the wide end now that I've been using it for a while.

You say you don't care about equivalence, but you also say I can't discuss the 28-105 if I don't have a K-1. Sorry, you lost me.

The OP is asking / opining specifically to the 28-105 on K-1. Norm is saying APSc format lenses (and comments thereto) on APSc cameras aren't automatically germane to the topic and possibly aren't relevant in any form or context. Of course you can post anything you want, but people might push back if you aren't posting about 28-105 on a K-1.

[starbase218]

The OP is asking / opining specifically to the 28-105 on K-1. Norm is saying APSc format lenses (and comments thereto) on APSc cameras aren't automatically germane to the topic and possibly aren't relevant in any form or context. Of course you can post anything you want, but people might push back if you aren't posting about 28-105 on a K-1.

I just looked up my original comment and I only mentioned APS-C glass in response to a comment made by biz-engineer, not the OP, regarding the purpose of this lens and its zoom range. He said that the 28-105 was a great landscape lens, I commented that personally, I'd like something wider for landscapes: 24mm on fullframe or 16 on APS-C.

I feel I shouldn't have to elaborate on this because it was a personal opinion as I stated. Actually, this isn't even important. It was a reply to biz-engineer's comment. Maybe it wasn't clear what I meant because people assumed I have a K-1. If that's the case, it's cleared up now. So can we please move on? Thank you.

Anyway, Spodeworld is the OP and he specifically mentions he would hate to give up the wider range of his 16-85 on crop for the 28-105 on FF. So it IS about range and he's already in the equivalence ballpark, so to say. Maybe we should let him decide which comments are useful to him and which are not?

[northcoastgreg]

The Sigma 12-24 f4.5 5.6 is 600 grams and 87mm wide and 103mm long and Full frame. Sizable but not massive. It doesn't need to be an F4 constant zoom (but it does need to be better than that Sigma).

Well if it does need to be better than the Sigma, it's probably going to wind up heavier than 600mm. And such a lens would be considerably more expensive. Quality is expensive in an FF zoom that goes out to 12mm. The Canon 11-24 costs $2,700. Would you really save that much money by making the lens an aperture slower on the long end? A DFA 18-35 f4-5.6 would no more be a duplicate than the DA 16-85 and DA 18-135 are duplicates to the DA* 16-50. Those of us who are landscape photographers don't need f2.8 and some of us resent the extra weight and cost. I've got bad knees and chronically sore feet. If I were a horse, I'd be sent to the glue factory, because physically, that's all I'm good for. There's no way I'm dragging big heavy FF zooms out into the field. The DFA 15-30 would cause me to regard anything more than 500 feet from the car as not scenic. I really don't want to be put in that position, as almost everything less than 500 feet from the car that is scenic in this country has been photographed to death.

Right now, if you want to use modern zoom glass designed for a 36 MP FF sensor that goes wider than 28mm, your only choices are the big, heavy and expensive f2.8 zooms. A DFA 18-35 would provide an option that is reasonably light while not being insanely expensive and would make for an excellent companion to the DFA 28-105.

There's another thing that a DFA 18-35 would bring to the table: filter rings. Right now there's no modern AF FF glass wider than 24mm with filter rings in the K-mount. For some of us who are landscape photographers, that's a big deal.