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CFV BACK SECOND TRY

Whoa Nelly !!! The print from that scan above just came out of the printer.

OMG !!!! it's so 3D looking I can hardly believe it. The web upload looks like crap next to this print. I just got a new PS action from a friend that I used on this image, and the final print looks like a Selenium Toned silver print when done on Crane's Museo Silver Rag.

All this exhausting digital talk ... man-o-man, film still has it's place in the scheme of all things photographic doesn't it?
 
Marc - a question out of ignorance - did you use a filter and, if so, which one.

Thanks in advance - Ted Rose (trying to learn as much as I can from those who know)
 
Marc

Nice image , in deed . Taken with film , good old film . Is there still image information in the bright parts of the roof on the negative ?
But Marc , sorry to say , Santa Claus has gone to sleep . Your image would be a very nice scenery for Santa .

Ok. Now to the facts . Could you have taken this image with one of your digibacks ?
The specs for HASSELBLAD backs are : 0 -45 C temperature . Mine (CFV , the bad one , will not work below +15C
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Is there a kind of "blimp" which would work as a kind of glove to keep the digiback warm ?

Jürgen and Tilt Sensor
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BTW i have written a serious letter to Christian Poulsen .
 
There's tone in the bright roof portion in the web upload, and the print Jurgen. Is your monitor brightness set correctly?

The tonal range of this shot was beyond anything that could be printed in one exposure ... either from film or digital. So ...

With the neg. film I exposed to just hold shadow detail, and when scanning made two exposures ... one for the sky and the other for the foreground ... then layered and merged in PS. Neg. film has more exposure latitude toward the highlight end than shadow end, allowing you to capture the mid and dark-tones without blocking ... then bring up the highlights in a second scan. In the darkroom you'd dodge and burn to achieve the same thing.

For a digital shot it's the opposite: expose to hold the highlights ... push the histogram as far right as possible without clipping ( not including specular highlights ), then do two raw conversions and layer/merge ... only the second RAW processing would be for the darks to control the shadow detail and suppress noise.

No filter was used Ted. It was all done in the digital darkroom, or could be done in the wet darkroom ... but only if the neg. has the Highlight and shadow information ... which this one did.

Using MF digital back in cold temps means following the manufactures spec's ... which are much colder than it's ever been in Michigan where I live. Actually, cold temps are suppose to produce even nicer files ( heat is the enemy, not cold ). So, I have no problems, and have shot in near zero F temps with the CFV.

What can be a problem is battery power being depleted by prolonged exposure to cold. However, when tethered to the Image Bank the back is powered by the Image Bank's battery, so you can put the unit in your inside pocket.
 
Hi Jurgen,

The sensor itself would be the bulk of the cost. The datapath needs a speed increase as well of course, but that is with modern chip technology not too much of a burden. Or cost factor.

At some point it would be interesting to check how much power the required faster electronics will need. Battery autonomy is important, more power -> bigger batteries -> higher weigth etc.

*The* way to lower the cost of a back would be using bigger chip wafers, allowing more sensors per wafer. Then make sure the yield is high, making sure that essentially all sensor chips on a wafer are OK. Then make sure that you run a big enough production, so that you can spread the original design cost over enough produced sensors. All in all this calls for using off-the-shelf sensors, so multiple vendors using the same sensors. Their distinguishing factor would then be more the ease of use, the quality of the image processing chips, their speed, the quality of their firmware(!) etc. And (last but not least) the build quality of the digiback itself.

The economies of scale for silicon chips produced in sufficient quantity are extreme.

Wilko

NB: have you considered changing your surname to "waagerecht" ? ;-)
 
Wilko

I do not quite understand what you mean by waagerecht . Please let me participate in your phantasy .
 
Ahhhhhhhhhhhhhhhhhhh

Wilko , now i understand . Yes , when my CFV BACK came back from the first repair in Sweden , and i took the first shot , this warning came up . It made me laugh so loud , that my wife was worried , what would have happened .
Tilt Sensor , i have never heard of that in the HASSELBLAD world before , so that i spontaneous declared that guy to be my friend . He , Tilt Sensor , will not be allowed to hang out everywhere in my HASSELBLAD gear , but he looked so hungry when he turned up , that i decided to feed him , when he promises to stay away from my future digital gear . He promised . In a couple of days , i will have a new E-MAIL address , holdinhg his name .

Jürgen and Tilt Sensor


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Marc

Your merging of two different "exposed" scans sounds very much like a kind of HDRI .
Please remember , that i opened a thread about this topic .
Can you please explain that in more in detail ? ? ?

Jürgen
 
You didn't take the back to the pub or anything, Jürgen?

Perhaps the 'tilt sensor' is for the operator and you triggered it by being a bit wobbly. Not sure how to re-set it, though.
 
Here's what I suspect Jurgen:

TILT SENSOR may be a method for lining up the sensor to be true level, and the designation may have been accidently left on in the camera by the repair tech. I know that there is data in some of these backs that can be accessed by the manufacturer.

Here's a clue from a web site about TILT SENSORS ...

"TILT SENSORS and inclinometers generate an artificial horizon and measure angular tilt with respect to this horizon. They are used in CAMERAS, aircraft flight controls, automobile security systems, and special switches. Important specifications to consider when searching for tilt sensors and inclinometers are the tilt angle range and number of axes. The tilt angle range is the range of desired linear output measured in degrees. The number of axes the inclinometer and tilt sensor measure on is another important specification."

Jurgen, maybe Hasselblad looked at your photos and thought you needed some help shooting a straight horizon. It's a digital "bubble Level" just for you ... LOL : -)

There are all kinds of things with TILT SENSORS built in, even this item from Leica ...


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Here's a special item just for you Jurgen ...

A watch to go with your custom Hasselblad "Tilt Sensor" digital back.

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I think many digital backs have tilt sensors to determine orientation. After all, you can mount a P25 in the horizontal or vertical positions and a sensor in the back can determine the mounting position and automatically rotate the image when opened in C1. It makes less sense in a square format back, but perhaps Hasselblad maintained a common design for all their backs. I just got my P20 today and it looks superb. We had a big snowstorm and I haven't had a chance to take it outside yet.
 
> O.K there are tilt sensors in the 22, 31, and 39MP backs so that the software can correctly orientate vertical shots. Quite why there would be one in a square chipped back is beyond me which leads me to suspect that the error message is erroneous.

Nick-T
 
"With the neg. film I exposed to just hold shadow detail, and when scanning made two exposures" post no. 396 from Marc

I wonder if Marc could explain this to me as I wish to do this but I can't. In my Flexcolor software there are two windows. I suppose one is for the digital backs and it allows exposure control. The other window is for scanning film but it has no exposure control. Could you explain how you scan in two exposures ?
 
Yeah, Larry ... that makes sense also. But I've never seen an actual read-out on the LCD saying "Tilt Sensor" ... which makes me suspect it's a tech designation of some sort.

The CFV and H3D are dedicated to one specific make of SLR camera, so a standardized method of sensor adjustment is most likely used.

In contrast, many of the backs designed to fit multiple camera platforms using adapter plates need the sensor custom adjusted to the specific camera body.

Many of the Digital back makers actually offer "shim kits" to help achieve critical focus ... those backs that use an adapter plate need shims to zero out the focus plane.

To quote an article reviewing all major digital backs including those from Leaf, Hasselblad and Phase One:

"All the backs need shims (a.k.a., foil stacks) between the camera adapter and the back itself to place the sensor precisely in the focal plane for a specific camera body, thus assuring the alignment of the sensor plane with the focussing screen of that body."

But even dedicated backs don't assure perfection. My Kodak Pro-Back 645C was supposed to be fit just for a Contax 645, but both the back and my specific camera had to be sent to Kodak to be calibrated together in order to correct a back-focus issue. This was due to less than perfect tolerances of the Contax 645 body according to Kodak. The 80/2 shot at its nearest focusing range could not achieve critical focus, and Kodak adjusted the sensor to be perfectly aligned. It was stellar after that.

My CFV, H3D/39 both are dedicated backs and both achieve critical focus using their respective fastest lenses. This dedicated notion has been criticized, but I personally like knowing the focus is on the money without fussing with shims.
 
Joseph, when in the scanning mode ( Scanner turned on, Flexcolor opened ), there are a number of ways to adjust exposure.

There are small Icons located in the main scan window under the title "Corrections"

When selected, each icon will open a different correction tool, including: "Histogram" with exposure correction sliders both vertical and horizontal ... "Gradations", also with exposure corrections via Curves, and a very useful "Shadow Depth" Slider ... "Color Correction" ... And , "Texture".

When scanning a frame, use the crop tool to select and area that also includes a bit of the film outside the image area. This gives the scanner a true black point to work with. Then click on the little A on the main scanner window for an automatic exposure adjustment to give you a starting point.

In each case, the little wheel looking icon can reset the original scan if you don't like the adjustments.

I am surprised that your dealer didn't provide some tutorial advice on the use of your fabulous scanner and its software.

Here's a screen shot of a scan I'm doing right now ... I put an overlay on it to show: #1 the Correction Icons ... #2, The Auto exposure icon.


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I can't do a screen grab of the open windows after clicking on the icons because they disappear when you move out of the program to use the "Grab" program. But just click on yours to open them, and then you can arrange them each any way you want.
 
Hi Marc,

The use of shims is not that strange, given that V system filmbacks also needed adjustment. Hasselblad has even designed a special alignment rigg for that purpose. But the alignment method for filmbacks is such that you cannot do that on a digiback (basically they gently hammer the back into spec ;-)

I'm sure Jurgen's tilt sensor would hate that >-)

Wilko
 
Marc

There is no alcohol in the game and also no hand hold shooting , but a tripod with a geared head having two "bubble levels" .
So my friend is just a nosy guy and wanted to let me know , that he is there . Tilt Sensor is watching me .
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Ok. I dont care any more , the warning should not be there and images should also be written onto the CF-CARD card , even at 0C , because that's what the specs. say .
I have written to HASSELBLAD and reported my problems with CFV back and requested to get a full replacement .
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So Jurgen, your dealer did nothing to resolve this issue? You have to write directly to Hasselblad yourself? How could that be?

Nick Tresidder knows more about these backs than anyone here, so his simple assessment that it's an error reading is probably it. The camera should work in the cold, so replace it, or get a refund and get a Phase One, Leaf ... a Scanner ... or whatever ... would be my last piece of advice.

No one on this forum can help. We tried, there's nothing more anyone can do here.
 
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