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Choosing a back for a Technical Camera

GrahamWelland

Subscriber & Workshop Member
Due to recent unfortunate events (self inflicted :deadhorse:), I'm now in the market for a new back for my Alpa Max plus, potentially, as a replacement for my D3x if I transition to using my Phase DF as my principal landscape DSLR. Budget for new retail is up to the Aptus II-8 ($15k), or if someone can give me a REALLY good reason why, potentially stretch (with some discomfort) to the Phase One P40+, perhaps bigger & better if I can find a refurb or private deal. Above that and it's into competing with a replacement Range Rover Sport ... and the camera loses at that point. The miserly part of me wants to keep costs reasonable as this is my expensive therapeutic pastime and not a business expense.

My question is what recommendations do folks have regarding #pixels vs sensor coverage primarily for use on a technical camera?

My Aptus 65 was 44x33mm and I know that I can obviously move to 40mp at that size via the Aptus II-8 or P40+. (or of course I could just get a Aptus II-6 as a replacement). However, the Aptus II-7 (or 75s etc) have larger coverage in terms of 48x36mm for a slight increase in resolution - I haven't done the math but I suspect merely due to extra real estate at the same pixel size.

The trade off as I see it with the larger sensor is that I would have a slightly larger image area to compose against on the ground glass with mask, which I would find useful but not compelling, vs higher pixel density at the same imager size. The smaller sensor size does have some advantages in terms of shift/rise coverage and lens sweet spot due to the crop. With the Technical camera I don't feel limited in any way as far as wide coverage is concerned as I'm not typically a super-wide shooter and actually stitching handles this for me.

What I haven't been able to ascertain is whether the 7.2 micron pixels of the II-7 (or II-6) would be beneficial vs the 6 micron pixels of the II-8/P40+ that provide the resolution boost. In an ideal world I would assume yes, at least based on my previous Nikon DSLR experience where big fat juicy pixels = more sensitivity/cleaner higher ISO support. However, I haven't seen anything to suggest the same is true with the MFDB's.

With respect to using the back with the DF body and lenses, there would be some advantage with a larger sensor coverage in so far as I'd get less of a crop factor on the Mamiya/Phase glass - the one area where giving up the Nikon full frame for wides is a concern.

Btw, I never did find any closure in the previous threads about the advantages of the P40+ vs Aptus II-8. I assume Sensor+ pixel binning for higher ISO support would be one (not really relevant for my proposed use) but were there others?

Thoughts & Fall 2010 perspective on this? Any field experience input would be very welcome in helping me decide (along with obviously my dealer discussions too).

Thanks in advance.
 
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GrahamWelland

Subscriber & Workshop Member
Btw, I'd also be interested in hearing from anyone who is using the Hasselblad backs on the Alpa too. e.g. CFV-39 which also looks like a good choice if I were to switch out the 645DF system which I'm not wedded to.
 
S

svema

Guest
Used Hasselblad H3DII-39 and digital back on Sinar p2. Now I use DF with Р65 + including on Sinar p2. If you don't remove from hands by means of chamber DF it is valid to you isn't necessary Р40 +. Р40 + who is necessary for that removes without a support on open diaphragms or on closed but with application of function a sensor control + (10МР). At Phase one colors are pleasant more.
 

thomas

New member
What I haven't been able to ascertain is whether the 7.2 micron pixels of the II-7 (or II-6) would be beneficial vs the 6 micron pixels of the II-8/P40+ that provide the resolution boost. In an ideal world I would assume yes, at least based on my previous Nikon DSLR experience where big fat juicy pixels = more sensitivity/cleaner higher ISO support. However, I haven't seen anything to suggest the same is true with the MFDB's.
Have not done and have not seen a direct comparision with the Leaf/Sinar backs (though there is a comparision P40+/P45+/P65+ at Capture Integration. I would assume the newer sensor generation with a smaller pixelpitch is about as clean as the older generation of sensors at base ISO... ?
The 6micron backs with a smaller sensor offer more resolution relative to the sensor plane for a moderate price (relatively). Then again, to me it's somehow strange to use a "small" sensor on a digital "large format" camera, for many reasons. I'd prefer an Apt.II-7 or P45+ over an Apt.II-8 or P40+ on a tech camera. But that has also to do with my lens choices... and stitching to increase the field of view is not always doable.
 

yaya

Active member
Graham with regards to A-II 7 Vs A-II 8; one of the gains achieved while moving from 7.2µ pixels to 6µ was that we managed to get more pixels per sq/mm without compromising noise and colour characteristics. If anything there's an actual improvement in both areas.

The 7 does have a larger sensor which is useful to some in terms of lens coverage
If your work includes stitching then this might be an advantage as you will have larger overlaps for a give ****, which usually helps tools such as Photomerge.

Both backs are now fully supported in Capture One including Live View on both the DF and any tech camera as well and LCC, so you get another option in using either Leaf Capture's simple and straight forward workflow or Capture One's advanced image enhancement tools.

Hope this helps

Yair
 

docmoore

Subscriber and Workshop Member
Btw, I'd also be interested in hearing from anyone who is using the Hasselblad backs on the Alpa too. e.g. CFV-39 which also looks like a good choice if I were to switch out the 645DF system which I'm not wedded to.
I use the H3D II 39 back with Alpa TC. Very easy to run but you need to supply power via external battery or imageBank through the 800FW port. Cable tethered to my belt pack becomes transparent and it does not hurt to have 100GB storage while shooting landscapes.

I think the CFV needed a battery off the bottom which may interfere with some tripod mounts. Perhaps Marc W can comment on this.

Some find a wakeup cable was necessary...I seem not to need it. Without microlenses the lens cast while present is easily corrected in Phocus. This picture shows the magenta/cyan cast with the 45:

http://forum.getdpi.com/forum/album.php?albumid=166&pictureid=1339

There are a few more pics from the H3D/Alpa/45 Apo Grandagon (Now called Alpa Apo Alpar 45/4.5) here:

http://forum.getdpi.com/forum/album.php?albumid=166

Bob
 

Guy Mancuso

Administrator, Instructor
Couple quick things 6 micron backs are a little faster to shoot on the DF. 6 micron has less moire' and also the Dalsa sensors have less color shift over the Kodak versions of the 6.8 microns. Leaf and Phase have there battery attached to the back so a little easier for tech cams as well. Personally for tech cams I would go leaf or Phase. Also the Phase backs P40/65 no longer need wake up cables but to save battery you can still use them with normal latency.
 
How about long exposure? Are all Dalsa sensors limited to less than 60 seconds, 30 seconds for Leaf, is this correct? The P-45+ can still do an hour or whatever. Perhaps a used P-45+ would be good.

There does not seem to be much discussion at all about using Leaf for landscape, mostly just studio stuff. I wonder why?
 

Guy Mancuso

Administrator, Instructor
I think we can maybe squeeze 2 minutes but it better be cool outside. If i was going with a older back for long exposures than the P45+ is it. Also a P25+ or P30+. They are all rated at 1 hour, Dalsa is not in any flavor. The one downside to Dalsa is time. The P30+ is out so forget about that with microlenses. The one thing with the Kodaks is more color shift when shifting so LCC are going to be needed. I don't know times with Leaf and Hassy products.

Also the new 6 microns from Hassy/Phase and Leaf is noise will be better at the higher ISO. There are some trade offs but myself i would go for a 6 micron even though limited exposure time
 

jlm

Workshop Member
The CFV backs fit in standard orientation, (i have used 16 and 39 on a Rollei XAct2 and Horseman SWC) and use their standard bottom mounted battery (a sony videocam battery, available in small and large.) I had no tripod or shift interference.
Blad does make a very trim offset battery holder for mounting the CFV's on the Blad Superwide.
needed a synch cable to the lens and as I recall, a dummy wake-up shot.
 

Jack

Sr. Administrator
Staff member
On the upside, I don't think you have a bad choice in front of you --

My experience in moving from the P45+ to the P65+ was about a one-stop GAIN in usable ISO in normal mode, and then of course with Sensor Plus, a tremendous gain to very usable 1600, which in my case was enough to allow me to sell my entire Canon kit.

As for choosing between the P45+, P40+ and Aptus 8, you have a conundrum. P45+ allows up to one hour exposures -- they do get noisy after 5 minutes, but are usable. Dalsa has a different, smoother look. 6u definitely shows less moire than 7.2u. Aptus 8 is a bit less expensive than the P40+, but the P40+ adds Sensor Plus...

I'm not familiar enough with Hassy to comment, but I'm sure there is an attractive choice there as well...

(PS, the 10 MP of the binned P40+ file may sound a bit anemic, but in reality I would say it is as "usable" as about a 15MP DSLR file for detail, then has better tonality and color.)
 

GrahamWelland

Subscriber & Workshop Member
Interesting re. The Sensor+. I guess without the AA filter you feel qualitatively that 10mpx acts like, what 12mpx+ from Canikon DSLRs?

I plan on keeping my D3s & zooms/macro glass primarily to support true high iso & long glass work for wildlife. That where I'd have a problem giving up my 200-400 & TCs for example, or 14-24 at the wide end. I don't see an alternative there with the DF & glass.
 

GrahamWelland

Subscriber & Workshop Member
Graham with regards to A-II 7 Vs A-II 8; one of the gains achieved while moving from 7.2µ pixels to 6µ was that we managed to get more pixels per sq/mm without compromising noise and colour characteristics. If anything there's an actual improvement in both areas.

....

Hope this helps

Yair
Thanks Yair, very useful.

I note that the II-7 / 75 are based on older generation sensors too. Is that still true or have the later generations adopted new/improved 7.2µ sensors too.

I'm starting to think that the II-8 / P40+ might be where I want to be. With my Alpa I had no problems with 3 images merges with the 33x44 sensor of the 65 and it seemed to work well even with 15mm shifts & 18mm rise too.

I do like the minimal LCC work needed with these backs too - I assume/hear that the Dalsa chips have the advantage here.
 

Jack

Sr. Administrator
Staff member
Interesting re. The Sensor+. I guess without the AA filter you feel qualitatively that 10mpx acts like, what 12mpx+ from Canikon DSLRs?
As I said above, more like 15. More accurately, I feel my 15MP of sensor Plus off the P65+ is BETTER than the 22 off my 1Ds3...

I do like the minimal LCC work needed with these backs too - I assume/hear that the Dalsa chips have the advantage here.
Indeed -- the nature of the Dalsa sensor design relative to Kodak keeps the color channels more co-linear as the image AoI gets more tangential...
 

GrahamWelland

Subscriber & Workshop Member
The one area I did find the Aptus somewhat more limited was with the higher ISO support. I never wanted to shoot above ISO 200 with it. The Phase P40+ would be slightly more versatile on the DF it would seem in that respect. For the Alpa there would be little to no difference I suspect since the times I'd want to shoot with higher ISO would likely be limited anyways.

Thinking about it, I never actually shoot the D3x above 400 either. When I need higher iso than that I normally reach for the D3s anyway.

Conundrums ...
 
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Guy Mancuso

Administrator, Instructor
You can do full res ISO 400 with no issues with the P40+. Graham take a look at these sensor plus shots. Now you know i own this back and for me to say I have no complaints it means something. I'm pretty damn picky. Obviously bigger LCD but we know that. LOL
http://forum.getdpi.com/forum/showthread.php?t=13379
also the s2 review shows a lot of nice P40 with regards to noise test check this out as well
http://forum.getdpi.com/forum/showthread.php?t=12243

Now I have recommended this back to several folks and not one of them has come back and said Guy you idiot what are you thinking. LOL

You obviously could go either way with leaf and Phase but if it was me it would be between these two for a tech cam. The Dalsa sensor( color shift to the plus side) and ease of use for tech cams make these two in my mind really good for tech cams. Your only real limitations is long exposures.

Plenty of Leaf/Phase dealers around you to help as well. The nice part is they are the same company and share there technology and you can use C1 on both backs with full support.
 

GrahamWelland

Subscriber & Workshop Member
Thanks folks. Seems like some deals out there too at the moment as well.

Guy/Jack - you make some compelling arguments for the P40+, particularly if I shift from my D3x to the DF for more DSLR landscape work. I just need to see what it takes to get me into one in the short term vs one of the Aptus backs. There's no great rush right now but some of the better deals might dry up in a month or two.
 
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