[Douglas_of_Sweden]

I have just purchased a new K20D, and am awaiting delivery. When I was considering which lenses to purchase, I was tempted by some of the premium DA lenses but decided to hold off because

1- Being a modestly funded novice, I didn't want to overspend on something I might not benefit from for a while

2- By the time I refine my interest, develop the skills, and save the funds, there may be a full-format Pentax that would render the DA lens obsolete.

Does anyone here have concerns about the useful life of their DA lenses? How long might it be before a full-format Pentax body renders them obsolete?

Thanks ahead of time for your thoughts. When I make the jump to premium lenses, I want to be confident that I can use them for a long time.

-David

Don't read that well reviewed book by your favorit author, she may write an even better in a few years.
Don't take that interresting job, there may be a better payed later on.
Don't mary that lovely girl, you may meet an even nicer girl next year.
Don't...

[Ash]

DA* 50-135 2.8 vs. Canon 70-200 2.8:

Not quite a fair comparison.
Different FLs, but generally DA lenses are reasonably compact.

[johnmflores]

Not quite a fair comparison.
Different FLs, but generally DA lenses are reasonably compact.

Different FLs yes, but very similar FOVs.

It's actually quite hard to find APS-C and FF zooms of equal FLs - it seems like the manufacturers are deliberately producing APS-C zooms with similar FOVs to FFs

[Ash]

Different FLs yes, but very similar FOVs.

It's actually quite hard to find APS-C and FF zooms of equal FLs - it seems like the manufacturers are deliberately producing APS-C zooms with similar FOVs to FFs

True that, but similar FOVs only between the 70-200 on a FF and the 50-135 on an APS-C - so still an unfair comparison.

If they both had the same FOVs on an APS-C cam, then they can be compared...
Equal magnification not FOV is what makes them comparable.

In any case, one can't really complain that DA lenses are any bulkier than FA lenses... (55-300 vs 70-300 for example)

[Rich_A]

If I can offer a possible different perspective... I've actually switched from a Full Frame Canon EOS system with 4 L lenses to the Pentax K-7 and a full set of limiteds as well as a 60-250mm. I shot with the Canon 5D, a 16-35mm f/2.8L, 28-70mm f/2.8L, 70-200mm f/4L IS, and a 300mm f/4L. I also had a 50mm f/1.4 lens for this kit. Prior to this I owned the Canon 20D and suffered through the typical "oh if I only had FF I would be all set" and "APS-C just doesn't cut it for me"...

I really wish others could have tried out the kit and made their own conclusions but I can share my quick thoughts. As others have pointed out, the difference in form factor is very significant. My 'smallest' L lens was the 16-35mm f/2.8L. It weighed in at a "diminutive" 640g (that's 22.6 oz. or 1.41 lb. for the metric-challenged in the group). That's the SMALLEST lens. The normal zoom was off the charts at 880g (31 oz. or almost 2 lb.). Strap that onto a 5D, itself weighing in at about the same weight and you're talking over 4 POUNDS around your neck.

Weight issues aside, the actual advantages of the image quality for me was really only with high-ISO shots and that really wasn't that big of a deal to me. For wedding photographers, indoor shooters, or night-snappers, this would have been an entirely different prospect -- a much bigger advantage. I shoot mostly outdoor portraits, landscapes, and wildlife (more on this below). The actual image quality isn't that different. Yes, I know! Blasphemy! All the forums out there tout their FF as superior. Yeah, you would too if you just wasted >$2000 on a FF body and another >$4000 on L glass! Trust me...

If you shoot wildlife, I just can't imagine why you would choose a FF unless you were being sponsored by a camera company. You give up a free teleconverter with every lens that has no drawbacks. No loss of light, no extra glass to blur the image... just sweet, sweet, free 1.5 or 1.6x. I had to use my 1.4x TC on my 300mm f/4L just to get a reasonable crop on larger wildlife. I'd take an APS-C sensor for wildlife any day of the week.

The final blow to my future as a FF owner was the cost of the lenses. Aren't we supposed to see technology drive DOWN prices?! I remember when an L lens was $1000. Now they're $1500 and climbing. Nikon has simply gone insane with their pricing on VR lenses. In-body image stabilization was the clincher for my shooting style. Cheaper "L-quality" lenses with a stable of manual focus image stabilized lenses was a sweet bonus.

Of course, my conclusions are based on my shooting style but I have hands on experiences with both systems as well as APS-C Nikons as well (a lot of people just make assertions based on conjecture and internet myth). If you actually print your photos (what?!?!) and don't give a crap about bragging rights or status symbols, just buy a Pentax and enjoy the benefits that come with being an underdog, like amazing Limited lenses that absolutely crush the build quality of Canon and Nikon's "consumer-grade" lenses (also read as cheap plastic tubes with glass). The contrast and image quality are stunning. The new DA* lenses are simply going to get better each year (and yes, probably more expensive but always less than the comparable Canikon).

It's all about the handling of the equipment, not always about how popular it is. Why in the heck do you think people are still shooting Leica! I guess they're considered fairly obsolete on a technical level but they are totally devoted to fit and finish as well as the obscure field of actual picture taking.

[Marc Sabatella]

The whole concept of 'Full Frame' is just a hang over of the old 35mm film days. There is nothing special or magical about the 36x24mm sensor size. As others have said it is just one size in a whole continuum of possible sensor sizes.

Now, as many here know, I'm no FF evangelist - quite the contrary. However, in discussions on these forums a few months ago, an interesting idea surfaced (first noted by Robin, I think): the 24x36mm format *is* magical in one semi-significant way. *If* we accept there is something "special" about the FOV provided by a "normal" lens (which for this purpose we'll define as one whose focal length matches the diagonal of the format, even though that's by no means the only possible definition), then 24x36mm turns out to be the format for which the simplest viewfinder design will provide 100% magnification at that FOV. Not actually true - you really would need a slightly larger format, or else a slightly longer focal length - to get to 100%. A 50mm lens is slightly longer than normal, but comes very close to 100% magnification on a typical FF SLR. Which is to say, the magnification through the viewfinder is very close to what you see with the unaided eye. Whereas the corresponding lens on APS-C - a 33mm lens - produces a very obviously smaller than life size view. Conversely, on a larger format camera, one might expect the "normal" lens for the format to produce a larger than life size viewfinder image.

So anyhow, FF is "special" in that a "normal" lens actually looks that way through the viewfinder. How significant this is, well, that's another matter. And of course, one can design viewfinders to make the image as big or as small as you have the resources to implement, so it's not exactly an inherent advantage of the format. But it *is* one in practice.

[Rich_A]

Good post, Marc. I have to say I was surprised at how this translates in actual use. When you hold a FF and an APS-C camera to each eye (I've done this) and look through the viewfinders, the scene is magnified exactly the same, the subjects are the same size. The difference is only in how much of the scene is visible, or the amount of cropping, if you will. It's tough to explain unless you see it but there really isn't any magic going on. They're both the same size, you just see more of the scene with the uncropped, or FF version.

[johnmflores]

If I can offer a possible different perspective... I've actually switched from a Full Frame Canon EOS system with 4 L lenses to the Pentax K-7 and a full set of limiteds as well as a 60-250mm. I shot with the Canon 5D, a 16-35mm f/2.8L, 28-70mm f/2.8L, 70-200mm f/4L IS, and a 300mm f/4L. I also had a 50mm f/1.4 lens for this kit. Prior to this I owned the Canon 20D and suffered through the typical "oh if I only had FF I would be all set" and "APS-C just doesn't cut it for me"...

Thanks for the firsthand experience, Rich. Much appreciated. Earlier on we were talking about FL vs FOV. In your experience and with your type of shooting, did you have to adjust to the APS-C lenses that gave you the same FOV at a shorter FL?

[Marc Sabatella]

Good post, Marc. I have to say I was surprised at how this translates in actual use. When you hold a FF and an APS-C camera to each eye (I've done this) and look through the viewfinders, the scene is magnified exactly the same, the subjects are the same size. The difference is only in how much of the scene is visible, or the amount of cropping, if you will. It's tough to explain unless you see it but there really isn't any magic going on. They're both the same size, you just see more of the scene with the uncropped, or FF version.

Exactly, which is why an APS-C camera can claim to have 96% or 100% magnification *when used with a 50mm lens* (and that's virtually always what it says in the fine print). The 50mm will be only slightly narrower than a true "normal" lens on FF, but is of course a much narrower FOV on APS-C. By the time you account for crop factor and mount a 33mm-ish lens to your APS-C camera, you're dealing with *much* less magnification.

This of course in turn prompts the question of what's so great about normal focal lengths anyhow, which is a recurring debate. You'll note that many coming from film will say "it's the focal length that provides magnification exactly the same as the unaided eye", but as this discussion points out, it's actually just a coincidence that happens only with 24x36 or slightly larger formats. At least if you define "normal" as being related to the sensor size - if we defined "normal" to be 50mm for all cameras, regardless of FOV, then the statement would indeed be true. it would just be odd, since of course by the time you take the picture and print it, no one will know or care how big it looked in that viewfinder - all we can see is what's on the print. So it makes much more sense for any useful definition of "normal" to be tied to sensor size. And that's where this "special" property of FF kicks in - it's the only format in which that particular FOV happens to yield something like 100% magnification by default.

[Rondec]

I think there is some unwritten supposition by many that full frame cameras are the way of the future. Eventually everyone will shoot with them as the price of the sensors come down. That is the underlying question in this thread.

The answer is very unclear at best, but my feeling is that overall the cameras are too large for the general public ever to enjoy lugging around. The problem is not just the cameras but as mentioned above, the lens size that makes these cameras so large.

In the end, most people don't really care about the size of the sensor, as long as the image quality is good. Over time, all sensors will improve. The question will be at that point, if people are willing to pay more money for a larger camera, if they can't see an obvious benefit in normal shooting situations. I don't know the answer, but I do think that APS-C is going to be around for a long time to come and the DA lenses will continue to work as well.

What you choose to buy should have more to do with whether you want faster focusing, wider apertures, smaller size. FA lenses are definitely faster lenses, while the DA lenses are smaller, with faster auto focus.

[Rondec]

I would just add that I would be surprised in ten years if the number of SLRs has not declined considerably. More and more people are using cameras in cell phones and ipods, etc. Since few of these photos are printed anyway, they don't really care if the image quality isn't great. I was in a museum the other day and a guy took a photo of his child with his cell phone in pretty low light situation. No flash or anything. I don't know what it looked like, but he looked at it and seemed pretty satisfied. This is the future, and the future is now.

[Rich_A]

Thanks for the firsthand experience, Rich. Much appreciated. Earlier on we were talking about FL vs FOV. In your experience and with your type of shooting, did you have to adjust to the APS-C lenses that gave you the same FOV at a shorter FL?

John, great question. I did have a tough time when I converted from film to APS-C (originally had a Canon 30D (no the other one, the actual 30D)). But then I got used to using it and simply convinced myself that it would be easier to switch back to FF where focal lengths (as Marc as discussing) were "normal". Well, to be honest, it's a totally different story nowadays. Lenses weren't designed for cropped sensors at first so you had to make due with large, odd focal length lenses (like the 28-70mm). Now they have lenses designed for wide-to-normal shooting, portrait focal lengths like the 50-135mm, and wildlife, basically anything over 200mm. My old film lenses worked great on the FF and were "the right" focal lengths but the high pixel counts on today's cameras are simply brutal when it comes to image quality. So, short answer, yes but with the new designed-for-digital lenses that's really a thing of the past... unless you're happy with the film lenses and then it's a moot subject entirely.

[Douglas_of_Sweden]

If I can offer a possible different perspective... I've actually switched from a Full Frame Canon EOS system with 4 L lenses to the Pentax K-7 and a full set of limiteds as well as a 60-250mm. I shot with the Canon 5D, a 16-35mm f/2.8L, 28-70mm f/2.8L, 70-200mm f/4L IS, and a 300mm f/4L. I also had a 50mm f/1.4 lens for this kit. Prior to this I owned the Canon 20D and suffered through the typical "oh if I only had FF I would be all set" and "APS-C just doesn't cut it for me"...

I really wish others could have tried out the kit and made their own conclusions but I can share my quick thoughts. As others have pointed out, the difference in form factor is very significant. My 'smallest' L lens was the 16-35mm f/2.8L. It weighed in at a "diminutive" 640g (that's 22.6 oz. or 1.41 lb. for the metric-challenged in the group). That's the SMALLEST lens. The normal zoom was off the charts at 880g (31 oz. or almost 2 lb.). Strap that onto a 5D, itself weighing in at about the same weight and you're talking over 4 POUNDS around your neck.

Weight issues aside, the actual advantages of the image quality for me was really only with high-ISO shots and that really wasn't that big of a deal to me. For wedding photographers, indoor shooters, or night-snappers, this would have been an entirely different prospect -- a much bigger advantage. I shoot mostly outdoor portraits, landscapes, and wildlife (more on this below). The actual image quality isn't that different. Yes, I know! Blasphemy! All the forums out there tout their FF as superior. Yeah, you would too if you just wasted >$2000 on a FF body and another >$4000 on L glass! Trust me...

If you shoot wildlife, I just can't imagine why you would choose a FF unless you were being sponsored by a camera company. You give up a free teleconverter with every lens that has no drawbacks. No loss of light, no extra glass to blur the image... just sweet, sweet, free 1.5 or 1.6x. I had to use my 1.4x TC on my 300mm f/4L just to get a reasonable crop on larger wildlife. I'd take an APS-C sensor for wildlife any day of the week.

The final blow to my future as a FF owner was the cost of the lenses. Aren't we supposed to see technology drive DOWN prices?! I remember when an L lens was $1000. Now they're $1500 and climbing. Nikon has simply gone insane with their pricing on VR lenses. In-body image stabilization was the clincher for my shooting style. Cheaper "L-quality" lenses with a stable of manual focus image stabilized lenses was a sweet bonus.

Of course, my conclusions are based on my shooting style but I have hands on experiences with both systems as well as APS-C Nikons as well (a lot of people just make assertions based on conjecture and internet myth). If you actually print your photos (what?!?!) and don't give a crap about bragging rights or status symbols, just buy a Pentax and enjoy the benefits that come with being an underdog, like amazing Limited lenses that absolutely crush the build quality of Canon and Nikon's "consumer-grade" lenses (also read as cheap plastic tubes with glass). The contrast and image quality are stunning. The new DA* lenses are simply going to get better each year (and yes, probably more expensive but always less than the comparable Canikon).

It's all about the handling of the equipment, not always about how popular it is. Why in the heck do you think people are still shooting Leica! I guess they're considered fairly obsolete on a technical level but they are totally devoted to fit and finish as well as the obscure field of actual picture taking.

Thanks Rich! Well written, thanks for sharing your real experience.

[Douglas_of_Sweden]

Now, as many here know, I'm no FF evangelist - quite the contrary. However, in discussions on these forums a few months ago, an interesting idea surfaced (first noted by Robin, I think): the 24x36mm format *is* magical in one semi-significant way. *If* we accept there is something "special" about the FOV provided by a "normal" lens (which for this purpose we'll define as one whose focal length matches the diagonal of the format, even though that's by no means the only possible definition), then 24x36mm turns out to be the format for which the simplest viewfinder design will provide 100% magnification at that FOV. Not actually true - you really would need a slightly larger format, or else a slightly longer focal length - to get to 100%. A 50mm lens is slightly longer than normal, but comes very close to 100% magnification on a typical FF SLR. Which is to say, the magnification through the viewfinder is very close to what you see with the unaided eye. Whereas the corresponding lens on APS-C - a 33mm lens - produces a very obviously smaller than life size view. Conversely, on a larger format camera, one might expect the "normal" lens for the format to produce a larger than life size viewfinder image.

So anyhow, FF is "special" in that a "normal" lens actually looks that way through the viewfinder. How significant this is, well, that's another matter. And of course, one can design viewfinders to make the image as big or as small as you have the resources to implement, so it's not exactly an inherent advantage of the format. But it *is* one in practice.

I've been wondering if Oskar Barnack had this in mind when he made the first Leica and created the 24x36mm format, but actually, I don't think so.

The usual explanation is that he took the hugh cinema rolls of his time and cut them down in shorter lengths, then loaded them horizontally in his prototype camera instead of vertically as in the cinema cameras/projectors. While the cinema used 18x24mm frames, to get a 2:3 ratio horizontal rectangle, he doubled the cinematic frame to 36x24mm (so 24x36 should be called double frame and APS-C should be called full frame...).

But the Leicas are rangefinders (actually, I don't think the prototype had a rangefinder, but anyway a separate viewfinder), so they did not look through the lens, but through a separate piece of optics with its own magnification ratio...so the behavior of 50mm lenses on the 24x36mm format must be a pure coinsidence! Even if later on SLRs took advantage of this, it was a pure luck that Leica made way for a film format with this property.

[jslifoaw]

One flaw in the APS-C to FF and FF to 645 is the fact that APC-C and FF share the same mount.

In going to 645 from either APS-C or FF you lose all functionality whereas APS-C and FF only differ in imaging circle; the AF, apeture, mount, etc. are essentially identical.

So, in going to a larger format, we can keep lenses working for APS-C to FF, but not from FF to 645. Additionally, body size is largely a function of consumer requirements more than physical constraints in APS-C vs FF. Observe how the K-7 is smaller than an E-30 or E3, or how large the Nikon D# was before the D3. However, the average size of a 35mm camera is always much less than the average size of any 645 camera, unless it's a rangefinder.

The comparison between the 50-135 and 70-200 Canon is also unfair because the Canon lens is effectively faster since for any AOV, it can stop down one stop to produce the same image as the 50-135. If you consider the 70-200 F4 Canon, you would observe a much smaller difference in size, weight, and cost. In fact, at wide angles, you would often notice that FF lenses are effectively smaller than APS-C lenses, unless you plan to use those lenses at smaller apertures most of the time in which case compact lenses like the DA21 do not have a real match (i.e. think about how small and cheap an FA31 would be if it was an F4.5 lens instead of F1.8).

It would be nice to be able to get back those fast apertures at wide AOVs with a FF Pentax, but until then I do have DA lenses to fill in the wide angle gaps albeit with small apertures.