[RioRico]

Existence is fraught with peril. Life is compromise. Perfection is fantasy. So we do the best we can. And we hopefully see past marketing hype that defines 'photography' as something that can only be practiced with Canon or Nikon hardware.

Are many trade-offs: budget, weight, AF speed and accuracy, availability, legacy support and compatibility, mood, job requirements, pro support, and likely more. We study and analyze -- and maybe base decisions on inaccurate data. Oops.

Probably the most important factors are budget and need and present kit. For those not heavily invested in one system, who NEED capabilities of an incompatible system, jumping isn't painful. But I don't upgrade nor replace; I supplement.

Those making their living by slinging cameras NEED to have appropriate gear. For the rest of us, it's a matter of desire. Should I NEED FF capability NOW, I'd find a way to budget for (argh) Canon -- most of my current lenses would be usable.

So, it's not a matter of casting-off from Pentax, but of supplementing what I have with further appropriate tools, as needed. Should I DESIRE something more... well, who knows? I am self-insured -- if I NEED more surgery, all the cameras will go.

Well, maybe not the Sony DSC-V1.

[ElJamoquio]

I'm not the one who wants this hypothetical (which is to say, non-existent) camera, *You're* the one who imagined it would be possible to assemble an FF system that was smaller than an APS-C system, so it's *you*, not me, that would benefit from this hypothetical (which is to say, non-existent) system.

It's not hypothetical, assuming you mean IQ in sharpness. Of course there are many other things that aren't directly comparable.

It comes down to a very simple question: can you or can you not assemble a *real* (not hypothetical) FF system that is equivalent to (in functionality and quality) but smaller than my current APS-C system, which consists of a *real* (not hypothetical) camera and *real* (not hypothetical) lenses?

In terms of lenses, yes. In terms of FF bodies, well if you're comparing camera bodies to equivalent camera bodies within the same manufacturer's base, yes.

Answer: you cannot, and presumably you know this or you'd have put up by now.

Actually you just weren't my top priority. I had done this so far:





But I was doing that to help a stranger who was asking for help on the internet. If instead you're just challenging me, then you can pay my hourly rate if you want me to go any further.

I have a degree in mathematics, and I can absolutely assure you that no mathematics known to mankind will make a false statement true. Although to be fair, I can see how one could possibly incorrectly apply the math to be misled into believing this - extrapolation of LWPH figures and so forth.

Wow, you went into a qualifications debate on the internet?

[jimr-pdx]

I would not choose a non-Pentax kit, this gear is too nearly ideal for me - but if I were leaving for some hypothetical reason, Nikon would probably be my choice. Canon's video obsession worries me, and Sony's philosophical schizophrenia in the past drove me away. I'd prefer not to dangle on the end of that rope again, thank you! I own a bit of older m4/3 stuff and I'd be OK with updates of that - it's the community that scares me there, with great compact gear scorned by many who Demand faster glass - and get (relatively) huge lenses and high prices, exactly what I do not want for cameras with a smaller sensor.

However if someone were to hand me a dSLR as a contest prize I'd probably take a Sony, as I really liked a few old Minolta-AF lenses in my A200 days.

[frank]

Together w/ Pentax, I've been enjoy using m4/3 (Pany G3 plus 14/25/45 lenses) for over half a year. If I were jumping ship, I'd just let go off my Pentax and stay w/ m4/3. Might get an OM-D soon...

[Marc Sabatella]

I have a lot of time for you Marc, but surely you don't need a math degree to work out larger sensor = less demanding on lens design? That said, it was probably going too far to state that a *crappy* lens on FF is better than a *great* lens on apsc...

Precisely. Yes, there are advantages to FF - more DOF control, more noise control, potential for higher resolution. But to imagine that you can get those advantage and also have a smaller system than APS-C - well, that's just not true, and it's so obviously not true I can't believe anyone is seriously trying to make that claim.

[Marc Sabatella]

It's not hypothetical, assuming you mean IQ in sharpness.

Again, that's just not true, although I can certainly see how a cursory look at resolution charts and a quick back-of-an-envelope calculation might mislead you into believing that. Try taking some actual images, though, and you'll quickly see that this simplistic view does not hold in reality, and then maybe that would give you the necessary incentive to work out the math for real to see why.

In terms of lenses, yes. In terms of FF bodies, well if you're comparing camera bodies to equivalent camera bodies within the same manufacturer's base, yes.

Again, if you really had examples, you'd have posted them by now, rather than incomplete charts and bad guesses on how math might work out for sharpness.

Look, if you want to maintain any credibility at all, your next post should be a single line naming the *specific* FF camera and lenses you believe would be an equivalent but smaller / lighter kit than mine. No other words of explanation should be needed. Either the camera and lenses exist, or they don't, and the mere naming of the models should be all the evidence you need.

But I was doing that to help a stranger who was asking for help on the internet. If instead you're just challenging me, then you can pay my hourly rate if you want me to go any further.

Again, since you are the one that wants this non-existent camera and lenses to turn into reality, I don't see why I should pay you to develop your own dream kit. it doesn't exist right now and will likely never exist, but if you wish to make it exist, by all means, start designing - and maybe someone else who believes it is possible will fund you.

[eddie1960]

Precisely. Yes, there are advantages to FF - more DOF control, more noise control, potential for higher resolution. But to imagine that you can get those advantage and also have a smaller system than APS-C - well, that's just not true, and it's so obviously not true I can't believe anyone is seriously trying to make that claim.

I would doubt a smaller system than apsc as well, but smaller than the existing FF dslr is another story. Something marginally larger than a K5 allowing for the bigger OVF and some more room for the Sr for the larger sensor should be well doable.
For me though the appeal of a Pentax system would be in the general ergonomics Pentax has (aside from the general FF advantages listed). All the high end apsc (K10/20, K7/5) have killer ergonomics very well laid out. Nikon comes closest here but still is not as user friendly
I'd say a FF could well be the last body I buy for a long time, but knowing my history that would be an outright lie. It may however satisfy me for a longer period of time allowing me to pour more photo money into lenses

[Marc Sabatella]

I would doubt a smaller system than apsc as well, but smaller than the existing FF dslr is another story. Something marginally larger than a K5 allowing for the bigger OVF and some more room for the Sr for the larger sensor should be well doable.

Yes, you could make a *body* that was only a little larger. Lenses are another matter.

[eddie1960]

Yes, you could make a *body* that was only a little larger. Lenses are another matter.

a constant f4 24-70 zoom should be about the same size weight as a constant 2.8 16-50 (they are pretty much equivalent) and they will likely cost about the same as well
the main lns advantage comes in the wide angles. with the registration distance k mount binds the brand to it's easier to develop faster better wides (a 21 2.8 should be doable about the same size as the 15 4.0 for instance, and a 21 2.0 the same as the 14 2.8 - not so much for the dof obviously but for the low light shooting ( a 20 f2 on ff would be a great street shooting lens)

There are gaps in the current line that would need to be filled for FF (135 for example) but most of those are gaps for the apsc crowd as well
the big gap would be in zooms there would need to be 3-5 new zooms (at a minimum)
12/14-24
24-70 - 2.8 and 4.0
70-200 - 2.8 and 4.0

for primes some of them would become more useful than they are now. the 31 and 43 ltd would really shine on FF. the 77 is already a great portrait lens and would continue to be so.

But the odds on a Pancake line like the DA one coming out on FF would be slim i think. Eventually maybe but there are far more pressing designs needed first and none of them are small (I'm not much of a zoom shooter, but I will acknowledge those zooms would be the most used byt a fair bit

a small wr kit zoom (like a revamp of the 24-50 f4) to pair with the 60-250 f4 which is FF in the patent would obviate he need for the slower zooms initially

[RonHendriks1966]

The big gap would be in zooms there would need to be 3-5 new zooms (at a minimum)
12/14-24
24-70 - 2.8 and 4.0
70-200 - 2.8 and 4.0

Well a smart way for Pentax to fix this is to make just a single line off zoomlenses that are smaller and cheaper and address to both pro- and amateur user.

12-24mm - f3.2
24-70mm - f3.2
70-200mm - f3.2

Lenses shrink fast when they are just a little bit slower. With current options for hi-iso use on camera's and still offering good background isolation, this would make a good pack of lenses.

Somehow I feel that on the wide-angle a 15-30mm/f3.2 would make more sense.

[Lowell Goudge]

Yes, you could make a *body* that was only a little larger. Lenses are another matter.

Define what you mean by lenses, because I can see this going all sorts of directions.

From a very simplistic point of view, for lenses beyond the focal length requiring a retrofocus elemenent, (i.e. specifically excluding lenses that have a focal length somewhat less than the registry distance and shorter) the lens dimensions are really independent of the format between APS-C and FF for any given focal length, because the mount diameter determines the rear of the lens and the full aperture determines the front element diameter. but. to get equivelent FOV/ AOV or what ever, at any given aperture, as you move into the tele range specifically, lenses get big and ugly in a hurry.

Just consider the difference between a 300/2.8 on FF and a 200/2.8 on crop sensor one has a 112mm front end, the other 77mm.

[Blue]

Well a smart way for Pentax to fix this is to make just a single line off zoomlenses that are smaller and cheaper and address to both pro- and amateur user.

24-70mm - f3.2
70-200mm - f3.2

Lenses shrink fast when they are just a little bit slower. With current options for hi-iso use on camera's and still offering good background isolation, this would make a good pack of lenses.

I partially agree. However, using a body with high iso and noise capability solely with relatively slow lenses is like using a Mazerati to pull a ski boat. They still need to develop some relative fast lenses but that could be done in the prime series with one or 2 f2.8 zooms worked in. In reality, Pentax has the optical formulas that could be tweaked. Then again, they have only been doing lenses since 1952.

[Lowell Goudge]

Well a smart way for Pentax to fix this is to make just a single line off zoomlenses that are smaller and cheaper and address to both pro- and amateur user.

12-24mm - f3.2
24-70mm - f3.2
70-200mm - f3.2

Lenses shrink fast when they are just a little bit slower. With current options for hi-iso use on camera's and still offering good background isolation, this would make a good pack of lenses.

Somehow I feel that on the wide-angle a 15-30mm/f3.2 would make more sense.

While this may hold true for the long end of the tele zoom range, not that size and focal length do not always track 1:1 at the shorter lengths, due to the needs determined for optical design.

[ElJamoquio]

Look, if you want to maintain any credibility at all, your next post

I have plenty of credibility. But no, I just don't have enough time (actually I do have the inclination) to educate you. You have the resources at your disposal - I'd suggest you start with the 40mm f/2.8 at FF answers and compare it to your 15mm cropped to 40mm. Don't forget to normalize to the DOF required for your assumption.

If your math works out that FF will always have larger lenses and that auto-cropping with the same lenses produces better IQ, well, I disagree with your application of math, but I can't correct every flaw.

Of course most people would choose to purchase or design a FF system that's larger overall with even better IQ and less tradeoffs, but that's not a fundamental limit of the FF system.

[Laurentiu Cristofor]

Just consider the difference between a 300/2.8 on FF and a 200/2.8 on crop sensor one has a 112mm front end, the other 77mm.

But that has nothing to do with formats - those are different focal lengths, so it is natural for the shorter telephoto to be smaller in all respects if it has the same aperture. If you want to compare equivalent lenses, on APS-C you would need to consider a 200/2. It would be shorter, but probably still about as thick as the 300/2.8.