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Hasselblad 50 mp backs superior on tech cams! Why didn't anyone tell us?

torger

Active member
At last I got some raw test files including LCCs for tech ultrawides for a Hasselblad back using the KAF-51000 CCD sensor (50.3 megapixel 47x39mm). It exists in the CFV-50 (recently discontinued) and the current H5D-50, and the older H4D-50 and H3DII-50, plus all the various multishot versions, H5D-200MS most recent.

This sensor has 6 um pixels just as the Dalsa sensors used in most current Leaf and Phase One backs, but has a few important differences. 1) it lacks microlenses, 2) it has much stronger shielding between adjacent pixels, 3) there is no tiling.

Looking at results from SK28 (the most extreme tech wide angle lens ever designed in terms of angular response) shifted all the way to the 90mm image circle edge I was really surprised with the result. There are none of the issues the Dalsa sensor is plagued with. Crosstalk is minimal (not visible), there is no tiling no matter how you pull the contrast, no microlens ripple (of course), color cast is there of course but certainly managable. As the sensor shields its pixels instead of crosstalking there's quite much pixel vignetting though, 2 2/3 stops at the 90mm edge (about 1 stop with the crosstalkin' Dalsa), so in tough light conditions with shadowy parts at the edge you may want to bracket.

I think this is pretty revolutionary results. Why? While backs with this sensor has existed since 2008, I had no idea until now that the Hasselblad 50s worked so well with tech wides, while the ubiquitous 6um Dalsa is plagued with issues and I've seen Capture One bending backwards to fixup microlens ripple, residual tiling (and indeed bent myself backwards to fix this in the LCC algorithm in Lumariver HDR I develop) and not always succeeding 100%, and certainly leaving crosstalk desaturation behind and sometimes even demosaicing failure. Resulting in people giving up the traditional designs and going for the more expensive retrofocus Rodenstocks.

Certainly many are happy with that, and the more complex Rodenstocks wides are indeed sharper when peeping, but among us that are still on legacy backs and happens to like symmetrical distortion free designs (both for how they render the image and the lower weight and price) this opens up an opportunity. As an alterantive to the "Phase One and only upgrade path" one can get one of the 50 megapixel Hasselblads, get some more resolution and perhaps more importantly buy a number of more years of time hoping for new sensor technology to arrive that better support tech cams (like a larger CMOS with wide angular response).

This is not only about the SK28 and SK35, although it's more evident on those. Also the 43XL, 47XL and 60XL through their super-large image circles push the Dalsa sensors into trouble space if you're the type that shift large amounts. With the Kodak 50 megapixel - no issues.

I find it surprising that Hasselblad marketing has not pushed this advantage more. Oh well, not too surprised, it's quite obvious that they're clueless when it comes to tech cams. But it's a bit sad that they have missed this opportunity to seriously compete with Phase One in the tech cam sector. I am myself a highly technical user (as I also write imaging software) so the fact that I have missed this performance advantage should surely mean that many/most others in the tech cam community have too.

In the future I hope more people will be aware of this option though when thinking about upgrading your legacy 22/33/39 megapixel back.
 

jotloob

Subscriber Member
Very interesting . Thank you . :thumbs:
I will take care of my CFV-50 , which I like very much .
 

Quentin_Bargate

Well-known member
I was aware that the 50mp Kodak sensor was better on a tech cam than the 40mp, because the 50mp version has no microlenses. However, I was not aware of the differences you mention between Dalsa and Kodak 50mp CCD sensors, very interesting.

Just as well, given I am about to mount the back from my Hasselblad H5D-200MS on a technical camera!

By the way, I suspect the reason Hasselblad don't push the point is because their backs are sold as part of a complete camera system, whereas Phase One backs can more easily be purchased separately.
 

torger

Active member
I've been looking back and forth between CFV-50, Aptus-II 10 or even P65+ as a possible next step. With this newly acquired knowledge the CFV-50 is back as a top alternative. I just need to stop with my pixel-peep chimping habit I've got by owning an Aptus.

Alternatively, if I go all the way to a H4D-50 I get a screen useful for pixel-chimping too, but need a third-party external battery, like Quantum Turbo 3 (which may not necessarily be a drawback).

H5D-50 has a battery adapter in the product line so it can be used in tech cam mode without third-party power, which is at least a little sign that they again look at technical cameras a little bit more seriously.
 

Quentin_Bargate

Well-known member
I think Silvestri make a power pack for Hassy cameras too. I will probably use Hasselblad's own power pack designed for the H5 series backs. I have shortened my tech cam list down to one - an Arca-Swiss Rm3di.
 

jlm

Workshop Member
i used to use the Quantum turbo 3; works great and can also power other usb devices, like your phone, and of course the Quantum flash
 
I was aware that the 50mp Kodak sensor was better on a tech cam than the 40mp, because the 50mp version has no microlenses. However, I was not aware of the differences you mention between Dalsa and Kodak 50mp CCD sensors, very interesting.

Just as well, given I am about to mount the back from my Hasselblad H5D-200MS on a technical camera!

can more easily be purchased separately.
I DID say on LuLa that the 28mm would work fine on your camera because it doesn't have micro lenses.:D
 

ondebanks

Member
Well done, Torger.

Sadly, this would not be the first time that manufacturers (and vendors) of MFD equipment weren't even aware of key advantages, or limitations, of their own gear! :shocked:

Ray
 

stngoldberg

Well-known member
I have been having extremely rewarding results with my H5D50 on my tech cam, yet I freely admit I didn't know the results were revolutionary.
Stanley
 

torger

Active member
I DID say on LuLa that the 28mm would work fine on your camera because it doesn't have micro lenses.:D
I've probably read it too... but it didn't stick at that time :-\

But now when I'm very familiar with the crosstalk problem (ie not correctable with any normal LCC process), and able to compare side by side the SK28 extreme-shifted on Dalsa 6um, and same lens on Kodak 6um, it all became so obvious -- the Hasselblad CCD 50 megapixel backs are very under-appreciated as tech cam backs.

It's unfortunate that Phase One never produced a P50+ back (which then probably would have been long exposure, something Hasselblad hasn't been able to provide), but I guess all effort was on the collaboration with Dalsa and wanting to phase out the "inbetweener" 49x37mm size.
 

cunim

Well-known member
Some years ago I was fed up with my H3D50 and (especially) Phocus for use on Alpa and AS Monlith cameras. I decided to try an IQ180. During that period I also evaluated an H4D50MS.

Initially it seemed simple. Dump the 'Blad and get the Phase - and my lenses were all Rodies so the 80MP problems seemed acceptable. Then I worked with the MS. My God what images. Not so much the resolution, which was great, but the colors and pixel integrity. Hard to define but my eyes just went "aahh" and relaxed looking at MS. I am seriously tempted to get another MS back, though everything I have is Phase now.

Point is that Hasselblad has the only modern MS solution today, and they are doing next to nothing with it. It remains a very "specialized" option. Given the spectacular image quality, that puzzles me. Realize economies of scale and put MS in everything. Take stance as "the beautiful image company". Worked for you before. Users are free to ignore MS and its little foibles until they need it. Oh yes, and fix up Phocus.
 

torger

Active member
I have been having extremely rewarding results with my H5D50 on my tech cam, yet I freely admit I didn't know the results were revolutionary.
:D

Many prefer the Rodenstock Digarons because of the better sharpness and don't mind the extra cost, weight and distortion, and would thus choose them anyway. With those lenses the Dalsa performs well, and on paper with a bit better dynamic range and color separation than Kodak (but I rarely see people complain about Hasselblad colors although they use this "inferior" sensor, so in practice I see no issue there).

However, for us on 22/33/39 megapixel backs with the angst "if I upgrade I'll downgrade my current lens performance, or I'll have to buy new costly lenses with design properties I don't really like that much", knowing about the Hasselblad option is kind of revolutionary, there actually is a back you can upgrade to and keep the rest of the gear intact.

It's also a good alternative to present to first time buyers. A Hasselblad 50 and SK wides can depending on deals be a considerably more attractive package than a Phase One IQ160 and Rodie wides, and not far behind in practical image quality.

The greatest weakness in this offer today is that CFV-50 just got discontinued (which in relative terms was attractively priced), and the H5D-50 cannot be bought without the camera (I think), so it's not actually that much cheaper than a IQ160 standalone back. In the pre-owned and second hand market better deals can be made though.
 

stngoldberg

Well-known member
I think Silvestri make a power pack for Hassy cameras too. I will probably use Hasselblad's own power pack designed for the H5 series backs. I have shortened my tech cam list down to one - an Arca-Swiss Rm3di.
Last evening, I shot 137 images on my H5D50 back with the Rm3di and still had battery power left....although. I don't know how much....I wish there was some way to get that data
As I have said on other threads, it only takes about ten seconds to change a Sony battery...they are small and cheap...I carry a spare in my pocket
Stanley
 

stngoldberg

Well-known member
Incidentally, the US representative for Arca is a guy named Rod Klukus. Although I have never met him, I have called and emailed him for advice; he has always been almost immediately responsive and helpful. As Torger has pointed out, Hasselblad including most of their reps are not especially knowledgeable regarding Tech cams, but Rod fills in the gaps
Stanley
 

Quentin_Bargate

Well-known member
Incidentally, the US representative for Arca is a guy named Rod Klukus. Although I have never met him, I have called and emailed him for advice; he has always been almost immediately responsive and helpful. As Torger has pointed out, Hasselblad including most of their reps are not especially knowledgeable regarding Tech cams, but Rod fills in the gaps
Stanley
Can you PM me his contact details?

Thanks

Quentin
 

Paul2660

Well-known member
Rod, who is a regular contributor to this site and others, you can reach him here:

Rod Klukas
US Representative
Arca-Swiss International
480-755-3364
[email protected]

He is a great resource on the Arca tech camera lineup.

Paul
 

torger

Active member
Another thing I forgot to mention, the Kodak sensor is stable both in horizontal and vertical orientation. In the test images I've got I have shift all the way to the edge in vertical orientation, but a bit milder shift in horizontal, still enough to quite safely make the claim that there is no significant difference between horizontal and vertical.

On Dalsa, and indeed the Sony CMOS, there's a large difference between vertical and horizontal.

I need red-filtered (or blue) LCC shots to measure the actual amount of crosstalk, but even with white ones I can get an indication by looking on how much the greens separate (one green gets leaks from red, the other from blue). With the H4D-50 tested here on the SK28 I get about 2% difference (I have the detection limit set to 1.5%, meaning there's crosstalk, but it's very low), with a Credo 40, which has Dalsa 6 um sensor, I get 50%. Just as an indication of the magnitude in difference.
 
:D

The greatest weakness in this offer today is that CFV-50 just got discontinued (which in relative terms was attractively priced), and the H5D-50 cannot be bought without the camera (I think), so it's not actually that much cheaper than a IQ160 standalone back. In the pre-owned and second hand market better deals can be made though.
Don't forget you can get the H4D 50 and a much lower price again the screen's the same. The sensor is the same. The ISO performance is the same as is the max shutter speed
 

torger

Active member
Good point, the H4D-50 is officially discontinued though, but I guess there are pre-owned deals.

One more note about these backs is that with today's standards they probably have the noisiest shadows around. Not by a big margin and not any worse than your 22/33/39 megapixel back, but if you're the kind of photographer that constantly battle with shadow noise in your post-processing, this is probably not the number one back. The recent Dalsa-based backs and especially the new Sony CMOS backs are much better, but then you have those other issues. You can't have it all.
 
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