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WAHOO 203FE back from overseas With CFV ability now

The 'active' bit is in the first image.

The second image shows were the lead going through the insert pops through with the pins that connect it to the shell.

The third image shows that all the leads connect to is a contact-flex (27), that makes contact with the Databus contact on the camera.
 
Hi Q.G.,

> The ELD's contacts do line up.

My mistake, I misunderstood the description of which ones were the “2nd” ones, and should have just looked at my own equipment...so I just looked at my 205 and E backs, and verified you are correct.

> So the E-backs' contacts and the ELD's contacts do not meet, so no > fear of a possibly harmful clash.

THAT makes some sense why they put two sets of contacts...one dedicated to the ELD (and probably the CWD), while still allowing the ELD (and CWD?) to be able to use the E backs.

> The 200-series cameras are a mix of electronical and mechanical > functional bits (much like the 2000-series cameras were too). > And i think they made the rear Databus in the 200-series do no more > than get ISO information, with nothing else 'hooked up'. No link > between the controller and the release mechanism, so nothing to > reprogram?

The 205 does have digital electronics in it, and this electronics does know when the shutter button is pressed, so it could easily transmit the “trigger” signal over the databus to the back in either the form of an I2C message, or an out of band signal (not part of the I2C protocol).

The rear databus certainly could do more than get ISO (like be used for the trigger ;-), but aside from the zone info on the TCC backs, there is nothing else that I’m aware of that it is used for.

Regards,

Austin
 
Hi Wilco,

> I would not be surprised if Q's theory is true that the filmback > provides nothing more than a voltage divider or somesuch to relay the > ISO setting to the camera. Judging from what I found in the back's > service manual exploded view there is not much, if any, advanced > electronics in there.

From the first picture Q.G. posted, it sure looks like they have a digital chip in the back (SOIC, surface mount). If I knew the part number of that chip, I could of course look up exactly what it is, unless it’s a custom chip they used. But, four wires to me mean power, gnd, clock and data...which is just what is required for I2C. A voltage divider would only require three, and then an A/D in the body to decode it. That, to me, doesn ’t make sense...but that doesn’t mean they wouldn’t have done it that way!

FYI, I have the full schematics for the Contax 645. It has a CPU in the back, in the lenses and in the finder (yes, all four have one CPU in each, the body has two), all that talk on an SPI bus (similar to I2C). If I had the schematics for the 205 and/or the back, I could easily see exactly what they did. Too bad they aren’t as readily available as the Contax information is.

Regards,

Austin
 
Perhaps one cann use an ohmmeter and test for us !
Perhaps 2 voltage divisors for ISO and for ZS needed for 205 TCC
Perhaps the digital chip is only an array or resistor to avoid "ton of resistor 1970's years look".

Thanks to O.G. for drawings. Does One have the CFE lenses diagrams too ?
 
Austin:

Perhaps you have a business opportunity designing a better conversion using modern electronics. I don't know if the Hasselblad service manuals contain schematics or it they are still available. Possibly a nearby repair facility may have one you could copy.

Regards:

Gilbert
 
Well, it may or may not have been possible to preserve the ISO setting ability of the e-backs ... but it sounds improbable if not impractical. Fact is, for what ever reason, they didn't.

That Hasselblad wasn't all that interested in preserving the e-film back's convenience is clear in that message posted earlier. However, it isn't as if you can't use a film back.
Again, IMO, the people that would've stopped from purchasing the CFV could probably be counted on one hand ... maybe one finger : -)

The CFV works marvelously on the intended camera ... the ubiquitous 500 series for which it seems to be selling well.

I still contend we 200 series camera owners are lucky. That they actually tipped their hat to a discontinued camera and made it possible to use this back at all is a first. Remember, no one, not even them, made a back that worked on the 200 series cameras at all. Prior to the CFV, there was nothing except a really in-elegant Rube Goldberg solution from Kapture Group that I didn't even consider after inquiring about it from other users.

Personally I want to see them succeed with this. The 500 series and CFV are in a separate group at Hasselblad and if it all goes south, the whole thing will be history. If this back revitalizes interest in old time Rock 'n Roll, and more people pull their mechanical wonders from the closet and press them back into service .... maybe they'll make a CFV MKII. It would be a place to use existing technologies that will fall by the wayside ... which I believe will be the case with the 22meg sensors.

What they need to do is eventually get the price down below $7,000. for the 16 meg version and bring out a 645 sized one with 22 meg. for under $10,000. At least we could use wider lenses in the landscape mode, and crop to a square when not. The old Kodak ProBack had a menu option that let you select Landscape, Portrait or the full square ... to save space and compose in the viewfinder, (those options were etched on the focusing screen).
 
Q

What is there name for part number 7 where the ISO setting dial attaches in the first diagram? It may be a logic circuit, or a resistive circuit that the camera measures a voltage drop.

Regards:

Gilbert
 
An interesting note on the V system “databus”:

http://www.obigo.com/composite-177.htm?pressIDH272

and I quote:

“For compatibility with future products the H-System is built modularly. The new camera system contains a completely new platform concerning control and communication built on a standard electrical interface, databus communication (I2C) and a programmable user interface similar the one used in mobile telephones.”

So, it appears they used I2C in the new Fujiblad cameras.

Regards,

Austin
 
Gilbert,

It just says "circuit board".

Detail:


26797.jpg


I think the tracks the button's contacts are dragged over are of the 'logic block' type (sorry for the layman's jargon), the type also used to code ISO values on 35 mm film cannisters.
 
I have looked for diagrams for camera or back, but can't find one (so far?).

The things were tested, not by using logic testers or multimeters and a diagram, but by hooking up the camera to a PC-based test system. The 'knowledge' a diagram would provide is 'burried' out of sight in this computer programm. So maybe no diagram ever made it outside the factory?

The electronics in the E-lenses aren't clearly shown either.
(By the way: the F-FE conversion kits were no longer available in 2000 already).
 
Austin, Q,

Unfortunately my service docs give me the same detail (or rather,
the lack thereof) that Q's docs do. Not surprising, as the
replacable unit will be the complete circuitboard, not the (chip)
component level. Thats the reason I asked for a picture of the
film back's guts. Exploded view does not give us more info. Someone
with a duff back out there willing to open it and photograph its
insides?

Marc,

No worries, this has become an intellectual challenge to figure
out the design. I agree with you that Hasselblad enabling CFV
use on the 203 is a nice idea. It is 20/20 hindsight
(I think that is the US expression for it?) to argue that things
could have been done differently. The question really is if anyone
could have predicted the speed with which digital capture has
taken hold of the photographic world.

Wilko
 
Hi Marc,

> Well, it may or may not have been possible to preserve the ISO setting > ability of the e-backs ... but it sounds improbable if not > impractical.

It’s hardly improbably or impractical. The databus is in fact a digital connection, pinned out as I suspected (two digital signals and two power). Here is a quote from the 205TCC brochure:

“All the lenses and magazines of the Hasselblad TCC-system communicate with the camera body using modern digital databus connections with just two gold plated electrical contacts needed for the data flow and two more contacts for the current.”

It IS digital, and is two wire for “data flow” and two for power, and is probably I2C.

> Fact is, for what ever reason, they didn't.

We KNOW they didn’t...and my point was they could have (and I’m %100 certain of that) added the trigger AND preserved the compatibility of E backs. I contend, and of course we may never know, the reason is purely poor electrical engineering, whether they just got lazy and let the mechanical guy figure it out, or they lost the source code to the CPU or what, doesn’t matter...it still, IMO, was not the right way to do it. It’s a hack.

Regards,

Austin
 
Hi Q.G.,

> The things were tested, not by using logic testers or multimeters and > a diagram, but by hooking up the camera to a PC-based test system.

I saw that too, but in fact the test system could contain logic and voltage tests. But, none the less, the 205TCC brochure states in no uncertain terms the databus is digital.

Regards,

Austin
 
Yes Wilko, I think MF was withering on the vine until the big meg chips came on line and all Hell broke loose.

Unless there is a technological "earthquake", 35mm DSLRs can now never catch-up. MF once again undisputedly wears the same image quality crown it had before the digital age swooped down on us all ... because just like with film, more real estate wins every time.

And thank God we can also still use film by just changing backs.
 
Austin:

If that is a multiplexing capable circuit, I agree and they could have approached it a number of ways, without losing anything.

According to the previous letter from Hasselblad posted, they just did not care about preserving ISO settings on the discontinued E backs.

I also use non E backs so in reality it really would not make a difference to me. But, given a choice for modification I would rather not lose anything.

Regards:

Gilbert
 
Okay, I guess it doesn't matter that it's all theory and the amount of users this will effect is so miniscule as to amount to a molehill of consideration.

The point about they "didn't do it" wasn't to state the obvious Austin, but to say that all the hand wringing and name calling won't change it one bit ... so why continue on and on and on about it?

What's the point? To prove you are right? So what if you're right? The back is what it is. So don't buy one if it offends you so much.

Meanwhile, back to important things ... lets see some photos. This stuff wasn't made to fill up e-space with engineering speak ...
 
Hi Gilbert,

> If that is a multiplexing capable circuit, I agree and they could have > approached it a number of ways, without losing anything.

It is capable of having multiple slaves...so yes, it is multiplexable. It is also capable of having multiple masters, but that is not needed in this case.

> According to the previous letter from Hasselblad posted, they just did > not care about preserving ISO settings on the discontinued E backs.

Understood. But, that may be just their way of “justifying” their methodology.

> I also use non E backs so in reality it really would not make a > difference to me. But, given a choice for modification I would rather > not lose anything.

Agreed.

Regards,

Austin
 
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