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Who needs more than 40mp on a MFDB?

fotografz

Well-known member
You are a good bloke Yair - but sorry mate - I feel very sorry for serious museums and galleries who get sucked into trying to replicate what a multi shot back delivers with a single shot anything...

You know very well that the multi-shot backs destroy any single shot elephant gun in that field..

If you want absolute best money can buy quality for that stuff - the choices don't include anything that Phase One or Leaf make...now do they?:toocool:

Love my Leaf back though:p
Ditto. For color accuracy, there is no single shot that can touch a Multi-Shot ... even the old ones are better.

-Marc
 

Guy Mancuso

Administrator, Instructor
What you are referring to is a split in the tech camera world - many say that the 33-40 mp backs are the sweet spot, yet most of the higher end discussion focuses on the IQ180 and 80 mp. What gives?

More resolution is certainly desirable, with greater information in the image and the ability to crop. However, there is another issue - that of system balance, as "lesser" backs are more forgiving. An upgrade in resolution to the 80 mp back has a ripple effect throughout one's system, with the new back cost, but also needing newer lenses, more processing speed, storage costs, etc. Its an intense upgrade, not quite foregiving on the gear, but one needing the best equipment.

With film, 6x6 shots on 120 roll film had inherent flexibility advantages over 4x5. While the larger film was more awkward, it gave better results, but at that time, it wasn't more costly - if anything, perhaps the MF gear was more expensive?

As the big dogs move onto bigger backs, there is plenty of room behind them. There are many very good lenses to enjoy, nicely priced as others move on. For everyone on the bleeding edge, there's room in their wake.
Well many of us will agree 40 mpx is a sweet spot in many ways. The real issue with that is the sensor size in 40mpx is a crop sensor as is the P45+ and pretty much everything in Phase /Leaf that is until you hit a 60 mpx back. I wanted Full Frame sensor so to get that I had to go with the IQ 160 or IQ 180 but outside of that I was content with the IQ 140. This is part of the issue plus I think also even though having a 40 mpx was nice its always nice to be a little over what you absolutely need. I never had a client complain about the 60 mpx back i had and if anything they where damn impressed by it, certainly they did not have one. LOL

Another issue NEVER heard before on this or any forum is figuring out lens conversions. Okay lets face facts every damn one of us STILL think in 35mm frame size for instance you walk into a scene and think immediately damn I need my 24mm. Now in medium format you need to do the math whats a 24mm on my crop sensor and frankly its a PITA . I found it so much easier for instance with doing that with a Full Frame sensor. Sounds weird because they both are simple math but I just had a block with the crop sensor. I maybe not be alone on this one either.

Also another major fact almost every deal or upgrade path has been on full frame sensors that actually lets say made some sense money wise. I'm getting this for that and i get 60mpx in the deal. Lets face it that is a marketing push on our heads, we all know it but the real deals have been on Full Frame which equals 60 mpx. Yea i know our arms are twisted like knots, damn marketing. LOL
 

torger

Active member
The problem I have with the latest backs is not that they have too high resolution, but that they work too poorly with traditional tech cam lens designs, and I find strong value in those: lower cost, more robust / lower risk for alignment errors (due to fewer lens elements), distortion free, lower weight. Low color cast sensors allow for unique lens designs that cannot be found in DSLRs.

I'm not 100% sure, but I suspect that it is harder to make small pixels with low color cast than larger ones, and therefore I'm a bit concerned with the current trend as a tech cam user. Traditional large format lens designs seems to be on the way out and soon every tech cam lens has a gazillion of lens elements in them just like on any DSLR to be able to support high resolution at large apertures in a race for megapixels, and focus stacking will become as common as in microscopy to be able to make use of all pixels. Maybe that is what attracts the typical customer, I don't know. I'd like to see something more balanced.
 

Guy Mancuso

Administrator, Instructor
Why I went with the IQ 160 , there really is no major issues with lenses. The 24 XL yes. The SK 28 a little but my bet now with C1 7.1 that slight magenta I got is now gone as they keep making C1 better in every version. After that its normal limitation stuff with any system or back. Sure no question the crop sensors may seem better but you still need to get wider lenses which are the touchy areas. Now Yair, Doug and such can correct me but Dalsa sensors are better on tech cams than Kodaks but there never has been a Full Frame Kodak sensor at least in Phase either.

No question these decisions are not easy to consider. You really need to do your homework and this forum is pretty good at helping people.
 

yaya

Active member
Pete next time you visit any of the 10 botanical gardens around OZ ask them what do they use for digitisation:toocool:

Marc I am glad that all those institute who are moving to 1-shot (if they haven't done so already) are doing their own tests and evaluations instead of reading these threads...

When was the last time you've used an Aptus-II 12 or a Credo 80 for reproduction? For the last 2.5 years I've been doing these tests and demos on a weekly/ monthly base and the pudding suggests that our recipe works really really well!

We are not talking 1-2 cameras here and there...here's a little example to a medium-scale project: Qatar funds £8.7m Gulf-archive project at British Library - The Art Newspaper
 

GrahamWelland

Subscriber & Workshop Member
Why I went with the IQ 160 , there really is no major issues with lenses. The 24 XL yes. The SK 28 a little but my bet now with C1 7.1 that slight magenta I got is now gone as they keep making C1 better in every version. After that its normal limitation stuff with any system or back. Sure no question the crop sensors may seem better but you still need to get wider lenses which are the touchy areas. Now Yair, Doug and such can correct me but Dalsa sensors are better on tech cams than Kodaks but there never has been a Full Frame Kodak sensor at least in Phase either.

No question these decisions are not easy to consider. You really need to do your homework and this forum is pretty good at helping people.
Of course if you are only using a tech camera, full frame is rather irrelevant and I think that there's a strong argument that the IQ140 is almost ideal unless you want ultra ultra wide. It will work with any of the tech lenses including the 24XL problem child that the FF sensors can't fully cover. You are also in the sweet spot of all of the glass with less edge issues, or potentially more shift/rise possibilities due to the smaller sensor that needs covering.

I was initially going to go with the IQ140 myself as the upgrade from my Aptus 65 (my P40+ was a cross-grade and so somewhat of an upgrade problem). However, in the end I knew that I'd want full frame anyway (it's in my nature :ROTFL: ) and I succumbed to Guy's GAS Jedi mind trick techniques ... and I'm happy I did actually but purely for tech cams I could have gotten away without it. Yes, 40mp was & is plenty. 60mp is nice but not a HUGE increase overall. :thumbs:
 
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timparkin

Member
Yeah... there are color differences, out of my experience Dalsa sensors seem more natural than Kodak, (the Sinar 75 version of the 33mp in particular) ...that's why I said earlier to Bob that I would ...prefer the ...Kodak sensor!!! ;) Indeed, Dalsa may be more natural, but what about taste :rolleyes: ...or a little over saturation for that matter? :thumbs: Don't forget Tim that Dalsa is more neutral than film ...and my 528c when shot in multishot more neutral than ...everything (not only Dalsa)!!! :chug:
Agreed - if you like the colour of any sensor then that's fine but coming from a point of view of loving film and working in the landscape, the IQ180 is closer to my preference.

Try looking at the images here..

http://static.timparkin.co.uk/static/tmp/cameratest-2/800px.html

Tim
 

torger

Active member
I think that there's a strong argument that the IQ140 is almost ideal
...and P45+ *is* ideal! ;)

Some shift stats of landscape orientation:
70mm image circle (wide angle Rodenstock Digaron-S)
54x40: 2.3mm/5.8% rise/fall, 1.8mm/3.3% shift left/right
48x36: 7.5mm/21% rise/fall, 6mm/12.5% shift left/right
44x33: 10.7mm/32% rise/fall, 8.9/20% shift left/right

90mm image circle (wide angle Schneider Digitar, Rodenstock Digaron-W)
54x40: 16.0/40%, 13.3/25%
48x36: 20.0/55%, 17.2/36%
44x33: 22.7/68%, 19.8/45%

I think a suitable shift range concerning composition possibilities is that you can get horizon up to 1/3 of a portrait shot (which actually is the shift range used in for example the TS-E 24 and PC-E 24 for Canon and Nikon). More than that is overkill, less is a bit limiting I think.

With that target, the 48x36/49x37 crop with 90mm image circle is the best balance. The 70mm image circles is a bit limiting even for the 44x33 size, then I rather go for 54x40 at 90mm.

The widest at ~90mm is Schneider Digitar 28XL I suppose, which is ~20mm 135 equivalent for 48x36, ~18mm for 54x40 and ~22mm for 44x33. And we have the Digaron-S 23mm which yields ~17mm for 48x36, ~15mm for 54x40, and ~18mm for 44x33.

Concerning lens designs it seems to me that 90mm lens circle with 6um pixel resolving power target makes it feasible with the traditional simple lens designs large format is known for, while when you go for higher resolving power you get much more complicated designs.

I think it would be unfortunate if future digital back development will only hold very small pixels and high color cast issues, which would lead to that these designs are made obsolete and put out of production. Because if you only need ~40-~50 megapixels you can get a very well-balanced system with the traditional distortion-free lower cost lower weight and more robust designs.
 
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GrahamWelland

Subscriber & Workshop Member
Now if there was an IQ145+ then I think that many people would be in digital back heaven. Well, certainly anyone who wants or needs to shoot for longer than a couple minutes or so. The P45+ in an IQ or Credo form factor with the enhanced UI really would hit the spot.
 

gazwas

Active member
Now if there was an IQ145+ then I think that many people would be in digital back heaven. Well, certainly anyone who wants or needs to shoot for longer than a couple minutes or so. The P45+ in an IQ or Credo form factor with the enhanced UI really would hit the spot.
When I was looking at the IQ's at first release I too thought the same and even expressed my interest to Phase One. However, I think that 39MPix Kodak chip is no longer manufactured so that quashes all chances of over 2 minute long exposures ever happening this side of a CMOS chipped Phase One back.:(
 

torger

Active member
When I was looking at the IQ's at first release I too thought the same and even expressed my interest to Phase One. However, I think that 39MPix Kodak chip is no longer manufactured so that quashes all chances of over 2 minute long exposures ever happening this side of a CMOS chipped Phase One back.:(
There's still the KAF-50100, the 6um 50 megapixel variant used by Hasselblad for example. From the data sheets most look the same as the KAF-39000 except smaller pixel size. There's no micro-lenses, the color cast seems as good/bad as the P45+. The requirement of wakeup procedure does not feel that modern though...

The Dalsa FTF-6080C 48 megapixel 6 um is also interesting I think, only(?) used in the tethered-only Sinar eXact. No long exposures possible with that though.

Both sensors are "old" technology though, would be nice to see some new development in the 6um pixel size in the future.
 

gerald.d

Well-known member
I can never understand the point of comparing "shiftability" of the same lens on different sized backs. Assuming same sized pixels (as is the case between the IQ160 and IQ140) you gain absolutely nothing by choosing the crop back.
 

gerald.d

Well-known member
...and P45+ *is* ideal! ;)

Some shift stats of landscape orientation:
70mm (Rodenstock Digaron-S)
54x40: 2.3mm/5.8% rise/fall, 1.8mm/3.3% shift left/right
48x36: 7.5mm/21% rise/fall, 6mm/12.5% shift left/right
44x33: 10.7mm/32% rise/fall, 8.9/20% shift left/right
The 70mm Digaron-W, which I use on the Max, can pretty much shift to the max of the Max on the IQ180 (shift +/- 18mm, rise/fall 25/18mm). It has a 100mm image circle.

90mm (Schneider Digitar, Rodenstock Digaron-W)
54x40: 16.0/40%, 13.3/25%
48x36: 20.0/55%, 17.2/36%
44x33: 22.7/68%, 19.8/45%
And that has a 125mm image circle, so if I can shift the 70HR 18mm, I rather suspect I'll be able to shift the 90 rather more than you mention there.

/edit

FWIW, here's the 70HR on the IQ180. 9-shot stitch (in portrait) to the full limits of the ALPA Max:



Full size is 280MP.
 

torger

Active member
I can never understand the point of comparing "shiftability" of the same lens on different sized backs. Assuming same sized pixels (as is the case between the IQ160 and IQ140) you gain absolutely nothing by choosing the crop back.
It's about economy.

We could have a chip say 90x90mm so we cover the whole image circle all the time and just crop in post, and then we could skip having movements on the camera at all. However a large chip is exponentially more expensive than a small chip, so with smaller chips you can make cheaper backs. Thus I think it is a good idea to not make sensors larger than they need to be.

I also find it more enjoyable to compose with the tech cam, shift the sensor into the right position, rather than cropping in post although the result is exactly the same of course.

Likewise, I think it is a good idea to provide lenses that don't resolve more than they need to do, as you can use simpler more cost effective lens designs.
 

torger

Active member
125mm image circle
Yes, image circles of longer focal lengths are generally larger -- it is unavoidable from the lens design. The 70/90mm IC limit is more clear in the wide end. Wide angles is the difficult part. Hard to make large image circles, hard to make sharp to the corner, hard due to vignetting and color cast issues.

I was not really clear either I realize now. What I meant with 70/90 is the image circle diameter, not the focal length. The Digaron-S wides has 70mm image circle, the Digaron-W wides has 90mm image circle.
 

gerald.d

Well-known member
Yes, image circles of longer focal lengths are generally larger -- it is unavoidable from the lens design. The 70/90mm IC limit is more clear in the wide end. Wide angles is the difficult part. Hard to make large image circles, hard to make sharp to the corner, hard due to vignetting and color cast issues.
Ahh. Apologies - you were talking about 70mm and 90mm image circles, I thought you were talking about 70mm and 90mm focal lengths.
 
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