Which MF system for me?

[Nebster]

Howdy,

I shoot primarily "semi-planar abstracts", a.k.a. brick walls. I tend to hunt for hours on foot until I find the one or two subjects that work for me. I use exclusively natural light, but it is not always in abundant supply. Today I primarily shoot D800e on a big tripod with Zeiss glass, mostly at 100mm or 135mm. I occasionally stitch several images to give me a bigger working area.

My goal is always large physical prints. I generally print at 30 or 40" in the small dimension, and as a consequence my (not big) house's walls are always at capacity with artwork. (Fortunately, I think within a few years 4K and 8K displays will largely solve this wall space problem. But let's leave that for another thread!)

I am curious what you all think would be the very best system for maximizing IQ in my scenario. (I suppose I should add the caveat that I am not interested in waiting ten minutes on a line-scanning back. The two things that seem like they should be of considerable interest to me are (a) movements and (b) multishot.

The movements I have very little experience with. One time I had a Canon TS-E and figured out enough to use it to get a receding plane (the ground) in focus from near to far. I am guessing I could also use movements, though, to help me get my brick walls in focus. I often struggle with this, getting squared up against the target, either because it is way too big, or because it is horizontal and I don't have a way to hang my camera in the air five feet above the surface (one tripod leg or another is always in the way). Today I either sacrifice getting the whole thing in focus, or I shoot multiples and focus stack later, or I just give up and move on to find something that works.

As for multishot, I have seen the Foveon and MS samples, and they just seem to have so much more information by oversampling the image circle. I love to shoot stuff that's oxidizing or that has other interesting color "issues" (e.g., metameterism), and I have a feeling the extra color data, to say nothing of the increased resolving power, would be valuable. However, I really do not want to tether a laptop or really even a surface tablet in the field. I already feel like what I have is too much gear a lot of the time?!

I should note that I really need a way to verify focus across the image field. My ideal camera would have a liveview mode where a small chunk of all four corners, plus the center, are shown in real time at the same time. No zooming out and back in or arduous scrolling back and forth across the image! But, since I'm interested in reality, I guess I just want to stipulate that if I go to MF I need a back that can deliver reasonable focus verification capability in some form. The faster, the better.

Okay, so, if cost is no object, what tools would you use to get the very best result in this scenario? Would you even bother with MF, or should I just press on with my Zeiss + Sony/Nikon kit? What else should I be thinking about?

Your comments are appreciated very much. Thank you!

 

[jlm]

we see a "which mfdb..." thread quite frequently, so do a search

 

[Nebster]

we see a "which mfdb..." thread quite frequently, so do a search

Three problems with this flippant response:

1. I've been on the Dpi and LL forums since they started, and I've read all the threads.

2. I've never seen anyone specifically search for a MF system with my shooting style. Closest would be be cultural heritage/repro guys, but they are all studio with the benefits that come along with that.

3. Old threads and discussion are quickly invalidated in the face of changing technology, so the search results from more than a year or two ago risk being irrelevant.

I do truly look forward to constructive advice and discourse and less dismissive one-liners. Thanks in advance.

 

[Jorgen Udvang]

This sounds like technical camera, of which I know little to nothing, or multishot, which is rather costly, territory to me. However, there is a solution available that is relatively cost effective:

The Fuji GX680 can be used with a Kapture Group stitching back to produce very large files. It's only available in V-mount. In today's market, that means one of the CFV backs. Other backs than Hasselblad or Sinar would involve Kapture Group's One Shot box, which many find inconvenient.

Using a digital back on a GX680 means a crop factor of minimum 1.5x if I remember correctly, but if you shoot with long lenses anyway, that shouldn't be much of a problem. It's a bit of an off-beat solution, but the GX680 is a great camera. I still use my GX680 III just for the pleasure of taking photos with such a fantastic tool. I only shoot with film when using that camera though.

Here's a link to the Kapture Group GX680 page:

http://kapturegroup.com/solution/two.html

 

[jlm]

for example, from this week: don't take it so personally
http://www.getdpi.com/forum/medium-.../50694-help-needed-getting-medium-format.html

or this one ;
http://www.getdpi.com/forum/medium-...ks/57096-mf-newbie-starter-digital-backs.html

another:
http://www.getdpi.com/forum/medium-...7026-new-mf-thoughts-hassey-vs-phase-one.html

 

[Geoff]

Three problems with this flippant response:
.

FYI - You might not want to consider anything from jlm as flippant. And while technology may change, it changes a lot slower in MFDB than you might imagine. MFDB is more about the principles than the current technological breakthrough, which can be largely overstated in consumer-grade photo world.

 

[Nebster]

The Fuji GX680 can be used with a Kapture Group stitching back to produce very large files.

Thanks for the interesting suggestion. I'll have to do some more reading; it's unclear to me what I'm getting from this very... interesting... looking camera. Is it primarily the ability to have a reproduceable translation of one sensor width in the "rear standard"? (Not sure I'm using the right words, but maybe you know what I mean.)

Sounds like it would be tough to frame with such a setup, but maybe there is a way to do that optically first? One of the issues I have with casual stitching in the field is that it's hard enough to get one frame sharp at critical focus on all sides... moving the camera then introduces a chance to get the second one slightly messed up somewhere, and so in post I end up with less keepers (or more blurry chunks that have to be painstakingly reblended) inverse-exponential to the number of images shot. It's tempting, then, to have a setup that lets me focus once and shoot once but yields a much larger capture.

Hmmm.

 

[Nebster]

for example, from this week: don't take it so personally

I don't even know your name; how could I take anything personally?

Don't worry, I have thick skin. And I could have expanded my introductory query to more pages at risk of scaring off people. Perhaps my initial inquiry somehow suggested that I might not have read the forums (I have), was not familiar with the digital backs that are readily available today (I am), or that I unfamiliar with the rigors of producing immersive huge output printed art (I am). I tried to convey that without wasting a lot of time and without spouting my whole resume.

So, yes, a half-sentence with no capital letters and the lack of tone on the internet (for all I know, you were making that twitter-esque response in a soothing, fatherly voice) is not much help. I'm looking for concrete feedback from people who might do things similarly.

As for the recent threads you pointed out, here is my problem:

http://www.getdpi.com/forum/medium-.../50694-help-needed-getting-medium-format.html

Specifically framed as beginning on a "tight budget." I'm not on a tight budget; I want to know what the best is. I already believe I can get results on my Nikon setup that rival the budget MF options, although perhaps not as quickly or easily/readily in some settings.

or this one ;
http://www.getdpi.com/forum/medium-...ks/57096-mf-newbie-starter-digital-backs.html

I'm sure this is a great guy, and it was a fine thread, but he wants to spend $2k on a back. I've specifically mentioned multishot as an interest above, and it's just a different price point and discussion I'm afraid?

another:
http://www.getdpi.com/forum/medium-...7026-new-mf-thoughts-hassey-vs-phase-one.html

This was another great thread, but the guy shoots sports and hangs off cliffs and stuff. That's so far afield from what I do that a lot of the responses are only helpful in general -- and, yes, to your point they tend to regurgitate product data and experience that has already been well hashed over in this forum.


My point is, again, then, that I feel like I am asking a question that hasn't been asked before. Maybe I didn't ask it clearly enough, but I am looking for insight and discussion. I hope this makes sense.

 

[Nebster]

FYI - You might not want to consider anything from jlm as flippant. And while technology may change, it changes a lot slower in MFDB than you might imagine. MFDB is more about the principles than the current technological breakthrough, which can be largely overstated in consumer-grade photo world.

The response was hard to interpret since a half sentence is guaranteed to be unable to convey tone, but yes, I thought it was flippant and unnecessary. I'm sure jlm is a nice guy, and he might even be a veritable fount on knowledge on this subject. But I have no idea?

I believe that, yes, the technology has changed so much that it has a huge impact on any decision where one is choosing to invest potentially $50k in a modern system. If Sony puts out a 6x oversampling 60MP CMOS 135 camera that composites in-camera and outputs 200MP images next year, I'm quite confident I could get better results with that with less time and money at least in many shooting scenarios. The financial cost of choosing a different path would be huge. So I must argue that assessing the state of any competing technology trajectory is a critical step, although I am not specifically asking about that here.

That analysis seems largely separate from understanding the advances vis a vis MF, which I think are equally relevant. For example, for shooting without movements, especially in the backcountry where weight and simplicity are paramount, I would gladly now shoot a CMOS back on an Alpa TC with one lens. The workflow that technology enables is a game-changer (just like it is for mirrorless 135). Sometimes I feel like it changes really slowly, as we watch the innovation happen in smaller formats first many times, but then in retrospect it has all changed quite quickly. At least enough so that threads from three or more years ago that opine on things, even seemingly static things like lenses, are often dangerously at risk of being moot. (Ray angles? Crosstalk? Oh my!)

I suspect that would you really mean is that parts of the toolchain are very high inertia. For example, I absolutely love the control I get with a couple of my Leica M lenses, with their silky focus helicoids that are probably the same design that they mastered the art of 50 or more years ago. No modern lens stuffed with electronics is really the same. Looking at all of this very expensive machined metal that I might buy, the same thoughts come to mind. I get it. But to make a system decision today without the benefit of today's tech (and tomorrow's direction) would simply be silly.

Lastly, Geoff, I hope I didn't*give you the mistaken impression that I'm interested in the "consumer-grade photo world" for purposes of this discussion, but if so, it wasn't my intention.

Whew!

 

[kdphotography]

Especially since you are not budget constrained---I would avoid the Fuji GX680. It will be much more difficult to make it play nicely with a modern MFDB.

Workflow and personal preference can be just as important as the MFDB and camera platform.

ken

 

[Geoff]

Howdy,

I shoot primarily "semi-planar abstracts", a.k.a. brick walls. I tend to hunt for hours on foot until I find the one or two subjects that work for me. I use exclusively natural light, but it is not always in abundant supply. Today I primarily shoot D800e on a big tripod with Zeiss glass, mostly at 100mm or 135mm. I occasionally stitch several images to give me a bigger working area.

My goal is always large physical prints. I generally print at 30 or 40" in the small dimension, and as a consequence my (not big) house's walls are always at capacity with artwork. (Fortunately, I think within a few years 4K and 8K displays will largely solve this wall space problem. But let's leave that for another thread!)

I am curious what you all think would be the very best system for maximizing IQ in my scenario. (I suppose I should add the caveat that I am not interested in waiting ten minutes on a line-scanning back. The two things that seem like they should be of considerable interest to me are (a) movements and (b) multishot.

The movements I have very little experience with. One time I had a Canon TS-E and figured out enough to use it to get a receding plane (the ground) in focus from near to far. I am guessing I could also use movements, though, to help me get my brick walls in focus. I often struggle with this, getting squared up against the target, either because it is way too big, or because it is horizontal and I don't have a way to hang my camera in the air five feet above the surface (one tripod leg or another is always in the way). Today I either sacrifice getting the whole thing in focus, or I shoot multiples and focus stack later, or I just give up and move on to find something that works.

As for multishot, I have seen the Foveon and MS samples, and they just seem to have so much more information by oversampling the image circle. I love to shoot stuff that's oxidizing or that has other interesting color "issues" (e.g., metameterism), and I have a feeling the extra color data, to say nothing of the increased resolving power, would be valuable. However, I really do not want to tether a laptop or really even a surface tablet in the field. I already feel like what I have is too much gear a lot of the time?!

I should note that I really need a way to verify focus across the image field. My ideal camera would have a liveview mode where a small chunk of all four corners, plus the center, are shown in real time at the same time. No zooming out and back in or arduous scrolling back and forth across the image! But, since I'm interested in reality, I guess I just want to stipulate that if I go to MF I need a back that can deliver reasonable focus verification capability in some form. The faster, the better.

Okay, so, if cost is no object, what tools would you use to get the very best result in this scenario? Would you even bother with MF, or should I just press on with my Zeiss + Sony/Nikon kit? What else should I be thinking about?

Your comments are appreciated very much. Thank you!

A few thoughts:

One way to start is to ask "movements or not?" - for the camera gear. Two kinds of movements to consider - rise and shift, parallel to the plane of the film (or DB) which impact composition, and pivoting movements, often referred to as tilt or swing, which affect focus plane. Its a bit more complicated, because on some of the more complex view cameras you can do combinations of front and back tilts and swings, and can really vary the focus plane quite precisely.

But it seems that adjusting focus plane isn't your interest, so lets consider just parallel movements, such as rise and shift. And if you are shooting "planar surfaces", then I'd really recommend you consider such movements. Thus the technical camera, often called a pancake type.

What back to put on this? Its a bit complicated. There is files size, but also sensor design, and micro lenses (some have, some don't). It does depend somewhat on what lenses you are using - for example, the Rodie 40 is a very good wide angle lens, tolerant of shifting, but pricey. Some of us in the next bracket down use other lenses, and pick our backs accordingly. But if price was truly no concern, then an IQ back (pick your size) or a Credo would be fine. Fast for focus checking, easy zooming, and very high quality.

Sensor type? If you plan on not using movements, the CMOS sensor gives live view, and would seem (at first glance) to meet your needs. But its not a large sensor (yet...) and some of us are still CCD fans. There are bigger sensors in CCD than CMOS. Also, CCD is more tolerant of shifting. So this is one area where you have to let go the old Canikon bias, and understand MFDB in its own way.

Multishot? Yes, it will give better files, but not critically so, unless one is doing really really precise fine art work. For out in the field, I wouldn't go that way (although maybe someone else will recommend it) as there are too many things that can go amiss. A good 80 mp back will do you just fine.

And yes, you need a rock solid tripod, and probably a geared head. And good technique.

Hope this helps get you started.

 

[gerald.d]

Forgive me for the brevity of the answer, but it seems clear to me that the following will be ideal for this requirement.

ALPA XY.
IQ3 80.
Rodenstock lens - we would need to know typical subject size and distance to pick the correct focal length.
Arca Swiss Cube
And a decent tripod (I'm not up to date on this)

Kind regards,

Gerald.

 

[Ken_R]

Howdy,

I shoot primarily "semi-planar abstracts", a.k.a. brick walls. I tend to hunt for hours on foot until I find the one or two subjects that work for me. I use exclusively natural light, but it is not always in abundant supply. Today I primarily shoot D800e on a big tripod with Zeiss glass, mostly at 100mm or 135mm. I occasionally stitch several images to give me a bigger working area.

My goal is always large physical prints. I generally print at 30 or 40" in the small dimension, and as a consequence my (not big) house's walls are always at capacity with artwork. (Fortunately, I think within a few years 4K and 8K displays will largely solve this wall space problem. But let's leave that for another thread!)

I am curious what you all think would be the very best system for maximizing IQ in my scenario. (I suppose I should add the caveat that I am not interested in waiting ten minutes on a line-scanning back. The two things that seem like they should be of considerable interest to me are (a) movements and (b) multishot.

The movements I have very little experience with. One time I had a Canon TS-E and figured out enough to use it to get a receding plane (the ground) in focus from near to far. I am guessing I could also use movements, though, to help me get my brick walls in focus. I often struggle with this, getting squared up against the target, either because it is way too big, or because it is horizontal and I don't have a way to hang my camera in the air five feet above the surface (one tripod leg or another is always in the way). Today I either sacrifice getting the whole thing in focus, or I shoot multiples and focus stack later, or I just give up and move on to find something that works.

As for multishot, I have seen the Foveon and MS samples, and they just seem to have so much more information by oversampling the image circle. I love to shoot stuff that's oxidizing or that has other interesting color "issues" (e.g., metameterism), and I have a feeling the extra color data, to say nothing of the increased resolving power, would be valuable. However, I really do not want to tether a laptop or really even a surface tablet in the field. I already feel like what I have is too much gear a lot of the time?!

I should note that I really need a way to verify focus across the image field. My ideal camera would have a liveview mode where a small chunk of all four corners, plus the center, are shown in real time at the same time. No zooming out and back in or arduous scrolling back and forth across the image! But, since I'm interested in reality, I guess I just want to stipulate that if I go to MF I need a back that can deliver reasonable focus verification capability in some form. The faster, the better.

Okay, so, if cost is no object, what tools would you use to get the very best result in this scenario? Would you even bother with MF, or should I just press on with my Zeiss + Sony/Nikon kit? What else should I be thinking about?

Your comments are appreciated very much. Thank you!

I would recommend you try a tech camera with a Rodenstock (up to 180mm FL available) or Schneider lens and a PhaseOne IQ back. The IQ150/250/350 is extremely versatile with gobs of dynamic range and awesome high iso and long exposure performance. Resolution wise the IQ180/280/380 is a monster. Large 6ft plus prints are no problem for this back when combined with great glass. The combination of superb tech camera glass (basically unmatched by SLR glass), high res back and camera movements of a tech cam setup will give you gobs of control and resolution.

 

[gerald.d]

Apologies - missed something. Currently Nebster is shooting with 100/135mm on 35mm, so based on that, Rodenstock probably isn't going to be your answer on the lens.

The 90mm is going to be too short, and the 180mm is going to be too small an image circle.

Therefore you're going to be looking at Schneiders.

I'm very familiar with the 120mm - it's basically all I shoot with these days (but very different to what Nebster is doing). That's probably too short though, so you'll probably want to step up to the 150mm or, probably better, the 180mm.

On a FF MDDB, the 180mm is going to give you close to the field of view (diagonal - ignoring aspect ratio differences) that you get with 115mm on your Nikon, so in the middle of your current two options. With a 120mm image circle, there is huge scope for shift-stitching.

Kind regards,


Gerald.

 

[gerald.d]

I just want to throw in one caveat here (posted separately to keep it distinct from the positives).

You mention that you only shoot in natural light, and that it is not always in abundant supply.

I'd strongly suggest you go back through your work and check what EV range you're typically shooting in. If you're regularly needing to open up those Zeiss lenses and bump up the ISO on your D800, then you may well be considerably challenged switching to MF.

In my experience, you really do want to be shooting at base ISO on the CCD backs wherever possible. On the IQ3 80 that I recommended, that means ISO 50.

On the lenses, you will be best off shooting at between f/8 and f/11. That's what they're optimized for.

ISO50, f/11 with your subject in shade is going to be around EV11-12. That means a shutter speed of 1/4 of a second. As long as you're comfortable in this ballpark, then you're good to go.


Kind regards,


Gerald.

 

[Nebster]

One way to start is to ask "movements or not?" - for the camera gear.

Thanks; like you, I like to frame the decision in a series of questions, and this seems like a great place to start.

But it seems that adjusting focus plane isn't your interest, so lets consider just parallel movements, such as rise and shift. And if you are shooting "planar surfaces", then I'd really recommend you consider such movements. Thus the technical camera, often called a pancake type.

Well, now here I'm not sure, but that's partly because I haven't done it ever. I have a ton of situations where I can't get the lens perfectly aligned to the subject plane, like when the subject is six feet talk and starts four feet off the ground. In those cases, I do end up pointing the camera up to get everything in frame. And that means my focal plane isn't parallel to the subject, which means I have to focus stack, which frankly kind of sucks. Especially if I want to shoot at wide aperture (to avoid being diffraction-limited), knowing that if I could just get squared up I would be fine.

So, that said, wouldn't I stand to benefit from non-parallel movements in these cases?

It does depend somewhat on what lenses you are using - for example, the Rodie 40 is a very good wide angle lens, tolerant of shifting, but pricey. Some of us in the next bracket down use other lenses, and pick our backs accordingly. But if price was truly no concern, then an IQ back (pick your size) or a Credo would be fine. Fast for focus checking, easy zooming, and very high quality.

I would probably choose a small number of the best lenses, and I do shoot some traditional landscape and would love one decent wide with some shifting capability. If anything, that seems like it's the biggest sweet spot differentiator for tech cam + MF, so I'd be remiss if I didn't also take advantage from time to time. Right now I use a Zeiss 15 and 21, but I confess that I don't typically find myself demanding critical corner sharpness with them.

Mostly, even when I'm shooting landscape, I'm almost always choosing a much longer lens and trying to isolate stuff, compress it, and "turn it into an abstract." The more it invites the viewer to wonder and puzzle, usually the happier I am with the result!

Sensor type? If you plan on not using movements, the CMOS sensor gives live view, and would seem (at first glance) to meet your needs. But its not a large sensor (yet...) and some of us are still CCD fans. There are bigger sensors in CCD than CMOS. Also, CCD is more tolerant of shifting. So this is one area where you have to let go the old Canikon bias, and understand MFDB in its own way.

Yes, I've seen the crosstalk stuff and am already quite familiar with it rearing its head in smaller formats with Leica lenses on Sony A-series. I also owned a Pentax 645D and was fine with CCD and liked its output, although I have seen a few CMOS images and don't really feel like there's some huge difference at equivalent noise levels.

Multishot? Yes, it will give better files, but not critically so, unless one is doing really really precise fine art work. For out in the field, I wouldn't go that way (although maybe someone else will recommend it) as there are too many things that can go amiss. A good 80 mp back will do you just fine.

I've been blown away by the (very small number of) samples I've seen online. They just seem so much deeper and better. On the other hand, best I can tell only a few of the older CCD backs have this feature and the compositing can only happen on a laptop, which would be a huge drawback for my style of working. I'd really like to avoid having a multi-step equipment setup and teardown at each stopping point, or at least have the option to skip it or go through it depending on how juicy I thought the subject was.

And yes, you need a rock solid tripod, and probably a geared head. And good technique.

I think I'm okay here, I have RRS, the cube, lots of experience hanging more weight, and I would really love an EFCS by the way but D800e beggars can't be choosers, ha ha!

Thanks for all the tips.

 

[Nebster]

Especially since you are not budget constrained---I would avoid the Fuji GX680. It will be much more difficult to make it play nicely with a modern MFDB.

Thanks for the pointer. I've never even seen this camera before, so it's kind of got my curiosity piqued regardless.

Workflow and personal preference can be just as important as the MFDB and camera platform.

Absolutely agreed. I am a computer guy and feel like I can learn new apps fairly quickly, but I'm also pretty eager to avoid adding more software to the pipeline. I don't particularly enjoy culling and the DAM aspects of photography, nor do I especially love waiting for stitches and stacks to finish compositing. I have consolidated entirely onto LR today, but I am willing to entertain C1, especially since people seem to rave over it. The last time I tried it was a few years ago, and at the time I felt like LR's noise reduction was a ton better, the exposure manipulation was about the same, and the local color control was better in C1. I would probably want to edit in C1 and move a final representation of the results to LR so that I can do DAM in one place, damn it. Hehe.

A dream scenario would be one where more of getting the result is done in the camera on the shoot and less is done at the computer later. To the extent I can reduce stacking and stitching, that would really help. But I am a pixel snob, and so I might just decide I need the extra resolution and the stitching. I just know I will not be able to resist...

 

[gerald.d]

oke:

Thanks; like you, I like to frame the decision in a series of questions, and this seems like a great place to start.



Well, now here I'm not sure, but that's partly because I haven't done it ever. I have a ton of situations where I can't get the lens perfectly aligned to the subject plane, like when the subject is six feet talk and starts four feet off the ground. In those cases, I do end up pointing the camera up to get everything in frame. And that means my focal plane isn't parallel to the subject, which means I have to focus stack, which frankly kind of sucks. Especially if I want to shoot at wide aperture (to avoid being diffraction-limited), knowing that if I could just get squared up I would be fine.

Shifting will deliver exactly what you need here - you set your camera level, focus on the wall, and then just shift the sensor around the large image circle that the lens projects.

 

[Nebster]

Thanks for the suggestions, Gerald. I'll interject a few thoughts/questions!

ALPA XY.

Yowzers, this thing weighs 2.6kg! That's, like, two and a half Zeiss 135mm's.

IQ3 80.

I'm very interested in IQx80, but I don't know what I get with 380 v 280 v 180. It looks to me like almost nothing that would be of value in my situation, but maybe I'm missing something. I have a flexible budget, but unless I'm missing something, I feel like I'd better off with two IQ180s than one 380, eh? I will say that in the past I've always traveled with two cameras: currently D800e x 2, or A7r and A7 with the Leica kit, or Pentax 645D x 2. I do like the idea that I can buy a cheaper "backup back" that can just drop in in the event that I do something stupid on a trip.

Rodenstock lens - we would need to know typical subject size and distance to pick the correct focal length.

Typical subject size varies from near-macro (typically 1:3 to 1:10 repro) to 8 feet square. If I could fabricate a lens as good as the Zeiss 135/2 at any focal length, I'd probably pick 85mm as the best hybrid. More often than not, though, I walk with the 100mm for the additional close focus flexibility it offers (and the lower chiropractic bills incurred after the trip).

Arca Swiss Cube
And a decent tripod (I'm not up to date on this)

I think I'm probly good here.

 

[Nebster]

I would recommend you try a tech camera with a Rodenstock (up to 180mm FL available) or Schneider lens and a PhaseOne IQ back. The IQ150/250/350 is extremely versatile with gobs of dynamic range and awesome high iso and long exposure performance. Resolution wise the IQ180/280/380 is a monster. Large 6ft plus prints are no problem for this back when combined with great glass. The combination of superb tech camera glass (basically unmatched by SLR glass), high res back and camera movements of a tech cam setup will give you gobs of control and resolution.

Boy, I'm ready to click the buy button right now, Ken! Ha, ha.

I feel like the 150 is a more versatile, and maybe resale is a concern since I have to imagine we'll see a fuller-frame/higher-density MF CMOS sensor one of these years. If we assume that I'm willing to buy the one or two best lenses for whichever of those backs, and we assume I'm willing to upgrade to a bigger CMOS chip later that might have some of the same crosstalk challenges, do either of those things lean you one way or the other on the back decision?