[Cynog Ap Brychan]

I see the arguments for the bigger OVF of a full frame, but - and it might be me - I don't really notice any practical difference in this respect between my K-5 and my D800. Both appear pretty clear, but neither seem as bright and large as the viewfinder of my Pentax MX, for example.

I understand the points about equivalency, but they're not often relevant to my type of photography, where I'm looking for more depth of field, rather than less. That said, I do like a shallow DOF for portraits, but while I could probably afford (and justify) purchasing a DA* 55mm, I can't afford (nor justify) buying the Nikon 85mm f1.4G. I do have the 85mm 1.8D, which probably gives a slightly, though not significantly, shallower depth of field than the 55mm, but I really prefer the rendering of the 77mm Limited. I bought the D800 for one reason only: its astounding resolution which is only bettered by much more expensive medium format kit. I can say though, if and when Pentax bring out a full frame camera, I will be getting one. If they can do for that what they did with APS-C sensors in terms of dynamic range, etc, it really will be a no-brainer for me.

[Class A]

I do have the 85mm 1.8D, which probably gives a slightly, though not significantly, shallower depth of field than the 55mm, ...

To give an as shallow depth of field as your 85/1.8 on an FF, the DA* 55/1.4 would have to be a 55/1.2 (f/1.16, to be precise) lens.

In terms of sharpness, the 85/1.8 would most likely outperform the 55/1.2 (due to the lower enlargement factor). AF will definitely be less challenging for the 85/1.8.

You can also imagine the difference in price.

[Cynog Ap Brychan]

Thank you Class A. I imagine the difference in DOF between a f1.2 and a f1.4 would only be significant in very critical cases, though I am willing to be corrected about this.

[Class A]

Thank you Class A. I imagine the difference in DOF between a f1.2 and a f1.4 would only be significant in very critical cases, though I am willing to be corrected about this.

Well, it is almost half a stop difference.

A 50/1.2 commands a much higher price than a 50/1.4 and I'd like to think it is not only because of the prestige factor. In any case, a good f/1.2 lens is much harder to manufacture than a good f/1.4 lens. Unfortunately the aberrations and cost do not rise in a linear fashion.

Purely theoretical talk can be a bit abstract, though, hence I recommend to scoot over to the "Full-Frame-Shots" thread and see whether you dig the look of FF shots. To me eyes, many of those shots have significantly better impact than typical APS-C shots.

[cali92rs]

Purely theoretical talk can be a bit abstract, though, hence I recommend to scoot over to the "Full-Frame-Shots" thread and see whether you dig the look of FF shots. To me eyes, many of those shots have significantly better impact than typical APS-C shots.

Where the 50 1.2 would be absolute killer is at f2.0 or f2.8 on a FF format. The lens would be nice and sharp in the in-focused areas and would still retain the really narrow DOF.

[noser]

Where the 50 1.2 would be absolute killer is at f2.0 or f2.8 on a FF format. The lens would be nice and sharp in the in-focused areas and would still retain the really narrow DOF.

I have a 50 1.2 and while I've not used it on a FF (even film), the challenge with 1.2 is that care must be taken to get an interesting or significant part of the image in focus due to shallow dof. So it's a game of distances, dof, and subject contrast and texture to get a nice image. Not impossible, but not for snapshots either.

As you suggest, things at 1.4 and 2.0 are much improved, and at least with my copy images are much crisper and the image is not generally 'soft' like it is at 1.2. Unless I'm doing beauty shots I actually prefer one of my AF 50's.

I managed to pick up that lens attached to an old film body for $35, but had I paid 10x or 20x more, with the intention of getting results like an 85 1.4 on FF, I would have been VERY disappointed.

[rob_k20d]

I almost certainly wouldn't get a full frame camera, as I seem to find myself wanting to downsize if anything. (I chose the K30 over the K5 largely because the K30 just felt that little bit lighter.)

But I would like Pentax to produce a full frame camera for this reason.

.

1) K-mount may not survive/thrive with mirrorless now slowly eating the lower end and value-FF eating the upper end of what was their aps-c market. Pentax without K-mount is just some other camera company.

[swingninja]

From personal experience:
1. Was in Fairbanks, Alaska. Shooting aurora with my Tamron 18-250. The result looks good, but cropped. I wish I have an FF so I can see what I've been missing.
2. Was taking pictures of friends in a costume party using my 50mm f/1.4. Room too small and too crowded. I couldn't stand far enough to capture the bottom part of the costumes.
3. Just bought a Zenitar fisheye lens (16mm). Couldn't get that "fisheye effect" since I used it with my K-x.

There are many reasons for Pentax to start investing in FF. But what I really want to know, why they haven't done it yet ? Why the wait ?

[bossa]

You forgot a couple:

+ friends and strangers look upon you with wonder and have to wear sunglasses due to your shiny awesomeness.
- you now have to take photos worthy of all of that extra sensorness. And no, cat pictures with a lot of bokeh does not count.

Yes they do

Rusty: Nikon D800E & Sigma 50 F1.4 @ F1.4


Rusty: Pentax K-5 & DA*55mm F1.4 @ f1.4

[bossa]

Where the 50 1.2 would be absolute killer is at f2.0 or f2.8 on a FF format. The lens would be nice and sharp in the in-focused areas and would still retain the really narrow DOF.

Exactly and because you are trying to maintain the same framing of the subject, the distance to subject gets smaller on FF and hence more OOF in back and a thinner DOF. (only if using the same actual lens though..)

[Pål Jensen]

You just have to accept that there are folks who live in the narrow DoF niche, for whom the absolute narrowest is essential. Or the psychological boost they get from knowing they have the highest level of control of DoF. Perhaps it's a confidence thing. My whole life I've been more concerned about getting more DoF not less. It's just this strange part of my make up. That's what I worry about. maximum DoF and sharpness. That doesn't mean I don't take narrow DoF images. It just means for some psychological quirk, I don't worry about being able to take them. Every one has their own quirks, and some really have become masters at narrow DoF photography, and that's a good thing, just maybe it's not for everyone.

99,9999% (I'm not even exagregating) of all published images (or images worth publishing) do not display DOF thinner than what can be acheived with APS. Of those about 99% will not suffer in any meaningful way with one stop more DOF (often hardly visible).
You do not get more control over DOF with larger formats just transposing the DOF scale one stop towards thinner DOF with FF vs APS. This means that you have to shoot at one stop slower shutterspeed for FF at the same DOF; a minus in most peoples book. In addition of course, most images display significant levels of DOF.
DOF is not an issue to make general statements regarding formats that are so close to each other as APS and FF.

[Pål Jensen]

Larger format give you certain "look", even on wider lens. One can get thin DOF on APSC (long focal length and close focusing), but the photo will look "flat". But look at photo taken with MF camera like the Pentax 67, they are so "alive", like you are there, a sense of immersive. Is not just DOF, I believe. FF obviously not as good as MF, but they are at a 'reasonable' price point than MF.
You can probably try to emulate this type of "look" on APS-C camera, by stitching, using long focal length and large aperture.
I know it is usually dangerous to show pictures when discussing this type of thing, but I will show several pics I took by stitching, that somehow give a feel of those large sensor camera give (my friends told me, so hopefully they are right.). If the pics fail to convey the idea, don't tease me ok?.... :-)

Looking at photos taken with FF and MF camera, this kind of "look" I believe is easy to get with FF or MF with just a single frame.
This is one of the main reason why I want a digital FF.

and like many others, I believe PENTAX will have one, eventually.

The MF look is mostly due to finer tonal gradations. Almost every single Pentax 67 shot, if not every shot, in Pentax long runnning Photo Annual book series is shot at F:22.

[monochrome]

In my own hypothetical experience using my brand-new-to-me MZ-S and FA50/1.4 and then my K-01 and FA 50/1.4, both at f/5.6, in order to achieve a similar DoF (about 12" from near limit to far limit) I merely have to back up about 20% (1 foot) and move the subject about 20% farther away from the background (2 feet) with the K-01. I suppose I ought to actually do something like this and post up

Of course that isn't always practical, but the reality is FF is sufficient to achieve a certain effect, but it isn't absolutely necessary.

IM not-so-H (in fact, actually somewhat arrogant) O, for anyone less than a true, large-printing pro, or a pro who actually sells to NatGeo, FF is like a red Ferrari. It is mostly an exercise in testosterone display, either by the user or the client.

Of course I would probably . . . .

[RobA_Oz]

From personal experience:
1. Was in Fairbanks, Alaska. Shooting aurora with my Tamron 18-250. The result looks good, but cropped. I wish I have an FF so I can see what I've been missing.
2. Was taking pictures of friends in a costume party using my 50mm f/1.4. Room too small and too crowded. I couldn't stand far enough to capture the bottom part of the costumes.
3. Just bought a Zenitar fisheye lens (16mm). Couldn't get that "fisheye effect" since I used it with my K-x.

There are many reasons for Pentax to start investing in FF. But what I really want to know, why they haven't done it yet ? Why the wait ?

After only 11 pages, we're back to the OP's question, or a form of it. There are many, and some even well-formed, views on why they haven't, if you read through the various FF threads here. The long and short of it seems to be the (small) size of Pentax's share of the DSLR market, and the reluctance of Pentax's former owner (Hoya) to risk the investment in a rapidly-maturing market segment. The present owner (Ricoh) has stated that they want to compete in all sectors of the camera market, and to grow their camera division to rival the leaders, although in other statements they have been a little more coy about a FF DSLR.

However, judging by your personal experiences, you could have got most of the results you wanted from a FF body by choosing different lenses for your existing APS-C body, even at the short end of your Tamron's range. A Sigma 10-20, Tamron 10-24 or Pentax 12-24 would have provided all the rectilinear wide-angle coverage for your aurora shots that you could have wanted. A 31 or 35mm lens would have been a better choice for indoor shooting of that type on an APS-C body than the 50, and there are several APS-C fisheye lenses that would have been a better choice than the Zenitar, which was designed for 35mm frame coverage..

[RobA_Oz]

Yes they do

Rusty: Nikon D800E & Sigma 50 F1.4 @ F1.4


Rusty: Pentax K-5 & DA*55mm F1.4 @ f1.4

Oh, no, they don't!

Hmm, let's see: cutesy cat photos or Anne Geddes baby photos... Which to destroy first?
So many puke-worthy photos: so little time...