[Nicolas06]

help...
micro four thirds - Does sensor size dictate lens size with all other things equal? - Photography Stack Exchange

Why does this indicate a size benefit to apsc?

So using a smaller sensor with a shorter focal lense work if the sensor provide enough detail and quality to begin with and the lense can follow.

To the extreme, why not just get a bridge? Small sensor, small lense, lot of reach ! But quite lower image quality too.

Each format comes with its limitations in term of quality. m4/3 isn't bad but is more limited for high iso and fine detail resolving power.

[Lowell Goudge]

So using a smaller sensor with a shorter focal lense work if the sensor provide enough detail and quality to begin with and the lense can follow.

To the extreme, why not just get a bridge? Small sensor, small lense, lot of reach ! But quite lower image quality too.

Each format comes with its limitations in term of quality. m4/3 isn't bad but is more limited for high iso and fine detail resolving power.

Jake the extreme of the Q. A P&S sensor on an ILC camera. I have used it a little for wild life and reach but the noise can climb in a hurry when you push ISO. That has always been an issue. But the Q is an extreme case, considering the same pixel density an APS-C camera would be 170MP.

The issue I have with the 450 long end, is that it is not really enough of a dofference over my APO70-200/2.8EX, which when paired with a 2X TC still gives excellent results wide open at max focal length (note later versions of the sigma 70-200 got a little soft at max focal length)

Now if they gave 500/5.6 at the long end, and was sharp wide open, that would be different.

[normhead]

Briefly, given that you get more magnification and a narrower FoV on APS-c, I'd ask, is the 150-450 a waste on a Full Frame? After all, long lenses are about subject resolution and magnification, and you get more of both on 24 MP APS-c.

[derekkite]

When it comes to shooting birds and wildlife, I've discovered that just about any lens made seems to come up about 100mm too short.

Pentax/Ricoh needed the FF camera to be a serious competitor in the industry. I certainly don't need a FF and I'm not likely to buy one. As for the new telephoto, that needed to be labeled as an FF lens as the Pentax lineup was lacking a lens of that size. It's an even more important addition to the lineup now that Sigma has dropped their 150-500 line and the new 150-600's aren't being produced in K mount. I really don't think building a 150-450 to fit the APS-C image circle would be significantly smaller and lighter to make a difference.

Camera companies all build products a lot of us don't use or need but that doesn't mean somebody else isn't going to use it or need it. Just as car companies need to build everything from small compacts to large pick-up trucks and SUV's, a camera company needs to compete in the marketplace and right now, that marketplace is demanding a FF camera.

I'm finding my 500mm a hundred mm to long.

On a full frame the 150-450 could be a very nice landscape lens.

[Lowell Goudge]

I'm finding my 500mm a hundred mm to long.

On a full frame the 150-450 could be a very nice landscape lens.

I think it really is a function of what your subject is.

Consider your bear shot. Replace the bear with a warbler, at about 1/10 to 1/20 the size and tell me 500 is too
long

Nice shot by the way

[formercanuck]

When you get to the long end of things, a lot of the size and weight is determined by the speed. For example, a 400mm f 2.8 lens would need a 143mm front element regardless of it being for APSC or FF.

Not quite... a 400mm f/2.8 FF lens would be significantly larger than a 400mm f/2.8 APS-C lens.
While the f/2.8 @ 400mm would make these lenses huge, having a smaller sensor means less glass in general (i.e. since you're cropping the image at the sensor, you can (should) have less glass if designed for APS-C. Otherwise, putting an APS-C lens on a Full Frame camera wouldn't give you a 'cropped' out circle image.
Putting a 400mm f/2.8 FF lens on an APS-C will work, but you'll be cropping out a good deal, and for the cost / weight, not always worth it.

[Lowell Goudge]

Not quite... a 400mm f/2.8 FF lens would be significantly larger than a 400mm f/2.8 APS-C lens.
While the f/2.8 @ 400mm would make these lenses huge, having a smaller sensor means less glass in general (i.e. since you're cropping the image at the sensor, you can (should) have less glass if designed for APS-C. Otherwise, putting an APS-C lens on a Full Frame camera wouldn't give you a 'cropped' out circle image.
Putting a 400mm f/2.8 FF lens on an APS-C will work, but you'll be cropping out a good deal, and for the cost / weight, not always worth it.

Youre right and wrong. Most 400 mm lenses and designs have the elements so far up the barrel that image circle is not an issue regardless. What determines the weight is really the front element because aperture is diameter /length, and the barrel diameter which is determined largely by lens mount throat. My 300/4 and the later M300/4 are full frame lenses lighter than the current DA 300/4.

You don't save a lot of weight in the intermediate lens groups. The mass is the front element and supporting it

[formercanuck]

Youre right and wrong. Most 400 mm lenses and designs have the elements so far up the barrel that image circle is not an issue regardless. What determines the weight is really the front element because aperture is diameter /length, and the barrel diameter which is determined largely by lens mount throat. My 300/4 and the later M300/4 are full frame lenses lighter than the current DA 300/4.

You don't save a lot of weight in the intermediate lens groups. The mass is the front element and supporting it

I agree with most of that... what I was getting at.. all things being equal - FF typically requires a BIG(er) chunk of glass at the end. Many modern Pentax lenses were based on FF lenses, and don't really have much difference in the build (eg. DA* 200 f/2.8 vs. FA 200 f/2.8

[Nicolas06]

Jake the extreme of the Q. A P&S sensor on an ILC camera. I have used it a little for wild life and reach but the noise can climb in a hurry when you push ISO. That has always been an issue. But the Q is an extreme case, considering the same pixel density an APS-C camera would be 170MP.

The issue I have with the 450 long end, is that it is not really enough of a dofference over my APO70-200/2.8EX, which when paired with a 2X TC still gives excellent results wide open at max focal length (note later versions of the sigma 70-200 got a little soft at max focal length)

Now if they gave 500/5.6 at the long end, and was sharp wide open, that would be different.

I don't really get your point...

On one side you accept to use a 70-200 zoom to match a 450mm. For this you clearly trade quality to get a 400mm frame and then you crop a bit to match 450mm so you got a 19MP shoot... Cropping a bit more to match 500mm mean you need to crop to 15.3MP. That's still plenty of available details as far as the sensor is concerned. Really there not much difference between 450 and 500mm...

But what is maybe different is the quality you get with 70-200 @200mm + 2X TC + cropping to 500mm or 150-450 @450mm cropped to 500mm or a 500mm directly.

Typically is the 150-450 is as great as 450mm than the 70-200 is at 200mm and you can use a 2X TC on the 70-200 without issue, you can just crop the 450mm shoots from the 150-450 to match 900mm.

[fredralphfred]

I agree with most of that... what I was getting at.. all things being equal - FF typically requires a BIG(er) chunk of glass at the end. Many modern Pentax lenses were based on FF lenses, and don't really have much difference in the build (eg. DA* 200 f/2.8 vs. FA 200 f/2.8

Yes. I probably didn't title the initial post properly, but this is the discussion I was looking for.


To clarify:


When you have a large (exclusive, in this case, since it has features aimed at only future cameras) base of APS-C cameras, wouldn't making a lighter, less expensive, longer, or faster dedicated lens for APS-C make more sense at that focal length? (I probably _should_ have asked if it was a waste on FF instead of APS-C.)


Does this indicate a wavering of commitment of Ricoh toward its APS-C format cameras (which has been unprecedented until now)?


I'll admit I bought into Pentax for the DA Limiteds. (The FA Limiteds didn't hurt, either, but mainly because of "pixie dust".) But now that I've a Pentax, since telephoto seems to "work better" on APS-C, why not exploit it?


I would like to see Ricoh succeed at whatever they try, because I can't see them folding up the APS-C line unless they fold up everything. But wouldn't they have been better off developing a magnificent wide-angle zoom that can really shine on full-frame and concentrating on APS-C for the long end? Or are they thinking, "It's going to be big anyway, so we might as well make it bigger." That seems to be the case, as all the telephoto lenses they've made so far, from what I've read, are supposedly "full frame." I can't argue they didn't have a gap to fill, but I think making it FF was an unnecessary compromise. Or is this just a re-work of an earlier lens (which doesn't make it "bad", but would make more sense if it saved them development $)?


I guess what I wanted was someone to come along and demonstrate that either the sensor size did or did not matter. Is there a rule of thumb, that with half the sensor size (or slightly less), you can gain a stop with the same amount of glass? Or perhaps gain x% mm? Just what am I, as an APS-C user, giving up with the full-frame compromise? (I don't care about 1/2 stop vignetting or anything like that.)



I've now seen arguments either way, without much to back them up. If everyone agreed, I'd be fine with that. But since they disagree . . .


I'm not talking about marketability, or demand. I'm really asking more from a simple physics point of view. If the difference is significant, I'd argue that it's more fear of the unknown on Ricoh's part rather than any market perception, anyway.


I am trying to clarify what I originally asked. I apologize if it's wordy. I've also heard that OP's can't "lurk" -- they have to comment or else people think they're no longer interested in the discussion. So this is a comment.

[jatrax]

When you have a large (exclusive, in this case, since it has features aimed at only future cameras) base of APS-C cameras, wouldn't making a lighter, less expensive, longer, or faster dedicated lens for APS-C make more sense at that focal length? (I probably _should_ have asked if it was a waste on FF instead of APS-C.)

No, not really. At the price point of long telephotos of this class it makes zero sense to have two models, one for APS-C and one for FF. And has been pointed out numerous times above the supposed savings in cost and size would be minimal. Now they could come out with a cheap consumer zoom but why? Another crappy lens that the reviewers will pan?

Does this indicate a wavering of commitment of Ricoh toward its APS-C format cameras (which has been unprecedented until now)?

No. Why would you even think that? Any FF lens can be used on APS-C so what's the difference if they make a new lens that covers both formats? And APS-C is still 90% of the market even for companies that have been in FF for years and years. it is 100% of the market for Pentax at this time. IMHO the only dedicated APS-C lenses we will see going forward are those that only APS-C needs such as APS-C UWA. The 16-85, and the coming UWA on the road map. You need dedicated UWA for APS-C you do not need dedicated telephotos.

but I think making it FF was an unnecessary compromise.

How? As noted by many above there is minimal (if any) savings for a dedicated APS-C telephoto lens. Take a look at the APS-C only DA 55-300 and compare that to the FA 100-300. 440gm for the "smaller, lighter" DA 55-300 with no aperture ring versus 390gm for the "bigger, heavier" FF lens. Granted the range is smaller but that is more a factor of modern lens design than needing to be bigger to fit FF.

[fredralphfred]

No, not really. At the price point of long telephotos of this class it makes zero sense to have two models, one for APS-C and one for FF. And has been pointed out numerous times above the supposed savings in cost and size would be minimal. Now they could come out with a cheap consumer zoom but why? Another crappy lens that the reviewers will pan?

I don't want a "cheap consumer zoom." I want a lens equivalent to or better than the 150-450 but dedicated to APS-C, if there's any advantage. You say no but several above say yes. Either the same specs but smaller & lighter, or the same size but faster or longer. I'm really asking "what can be done?"

No. Why would you even think that? Any FF lens can be used on APS-C so what's the difference if they make a new lens that covers both formats? And APS-C is still 90% of the market even for companies that have been in FF for years and years. it is 100% of the market for Pentax at this time. IMHO the only dedicated APS-C lenses we will see going forward are those that only APS-C needs such as APS-C UWA. The 16-85, and the coming UWA on the road map. You need dedicated UWA for APS-C you do not need dedicated telephotos.

Again, that's assuming there's no advantage. I've seen considerable debate about that not only in this thread but elsewhere. I want people to convince me one way or the other.

How? As noted by many above there is minimal (if any) savings for a dedicated APS-C telephoto lens. Take a look at the APS-C only DA 55-300 and compare that to the FA 100-300. 440gm for the "smaller, lighter" DA 55-300 with no aperture ring versus 390gm for the "bigger, heavier" FF lens. Granted the range is smaller but that is more a factor of modern lens design than needing to be bigger to fit FF.

Ahh! There! That's the sort of comparison I'm looking for. I'm not familiar with any of the old lenses. What comparisons are applicable? Is the FA 100-300 "lots yuckier" than the DA 55-300, so perhaps less good glass? Or are they mainly equal? I looked at the DA 20-40 vs. the FA 20-35, and the DA 20-40 is about 16% heavier. (Of course, it's all aluminum, has a DC motor, and is WR. It's a little faster on the fat end, but how much difference would that make? Or does the extra length significantly affect the relative size and weight of the lens?) I guess what I was hoping for was that there were some formulas somewhere that someone with optics experience knew that lens designers used to decide if certain lens goals were "do-able". Something that might explain why there's a big advantage to the DA 40 XS (9.2 mm, 52 g) over the DA 40 Limited (15 mm, 90 g) but not in telephoto land.


Pentax seems to have made this difficult by re-using lens designs wherever possible. I can't really blame them for that, but it does make me wonder what a redesign, perhaps not to the XS extreme, of some of the telephotos would actually do. I would actually buy the DA (probably HD) 40 over the XS because it's a lot easier to handle. But since I've got a FA 43 . . .

[derekkite]

The DA560 is aps-c. It is long. The long lenses for m4/3 aren't small. The size advantage of the lens occurs at short focal lengths, For long the crop factor makes a 450mm seem longer on an aps-c, giving an advantage to that format for shooting long.

The weight and size differences would be minimal at best.

[jatrax]

Ahh! There! That's the sort of comparison I'm looking for. I'm not familiar with any of the old lenses. What comparisons are applicable?

There are, I think, too many variables to make a simple statement. Take the 20-40 vs 20-35. One is APS-C but it is actually more expensive and heavier. But it is a 'limited' rather than a regular lens so how does that factor in? Or my 55-300 example where again the APS-C lens is heavier but it has a longer range.

It is easy to say "an APS-C only lens is smaller and lighter because it only has to cover the APS-C image circle". But lots of other things intrude to make that statement problematic. I am confident that an example can be found, though I looked and could not find one. I am confident that examples can be found to prove the opposite as well, in fact we just discussed two.

One thing that can be said is that the front element of a lens is most likely the heaviest and biggest part of a lens. And the size of that element is determined (mostly) by factors that have nothing to do with the sensor size. So a 400mm f/2.8 will have to have a certain size front element no matter whether it is for APS-C or FF.

But I suspect the most important factor will be economics, not whether it could be done. Could Pentax make a 150-450 that was smaller and lighter if it only covered the APS-C image circle? Maybe, maybe not. But will they carry two lenses the same size in the catalog? No. They will build a lens that they can sell to users of both formats. So whether it is possible is immaterial. It is not going to happen because of factors that have nothing to do with whether it could be done.

But to your original question:

Is Pentax ever going to, or do you think they should, come out with serious dedicated APS-C telephoto lenses? How much better could the 150-450 be for APS-C if Pentax had decided to add more support for its most popular size? For the same cost, weight, and size, could it have been an f/3.2-4.0?

Why would they want to? It would not be any 'better', how could it be? It might be lighter, maybe. Or maybe not. We do not have much to compare to as no other similar Pentax lens has this internal motor.

Perhaps we should look elsewhere for an example. Has any other manufacturer made an APS-C only lens in similar focal range? I don't have extensive experience with other brands so I don't know, but maybe someone else can point to an example.

[fredralphfred]

. . . But to your original question: Why would they want to? It would not be any 'better', how could it be? It might be lighter, maybe. Or maybe not. We do not have much to compare to as no other similar Pentax lens has this internal motor.

Perhaps we should look elsewhere for an example. Has any other manufacturer made an APS-C only lens in similar focal range? I don't have extensive experience with other brands so I don't know, but maybe someone else can point to an example.

You know, I keep thinking I should look at Sony's or Fuji's catalog for this comparison, but then it occurs to me that those are new mounts, rather than "old" reflex mounts like the K. One thing everyone seems to agree upon is that the flange-back distance makes a HUGE difference in lens size, so those wind up being immediately irrelevant.


I prefer optical viewfinders, so I choose to live with a rather large flange-back distance. Plus, I already have a Pentax, having consciously eschewed mirrorless cameras in their infancy.


I also have a Katz-Eye.