Hasselblad Infinity Desparity Question.

[Mark Crabtree]

I often found inaccurate focus with 500C and CM bodies and assumed this was the screen not being positioned properly.

I think you are mixing 3 separate issues into one. Lens collimation for infinity. Lens flange to film plane accuracy. Lens flange to focusing screen accuracy.

I believe that would be the order to check them in if you had the equipment, but the simple test is to do a focus test with film. See if the object focused on with the viewing screen is what is actually in focus on film. When you compare several cameras you may find that the bodies are focusing the lens the same at the film, but just the screens are off. Either way, you will now have an idea of where the problems actually are.

 

[RalphLambrecht]

mine too1. THE OP SHOULD TURN HIS CARPET TOWARDS GOETEBORG AND PRAY 500 HOLY VICTORRS.

 

[henry finley]

You're right. Lens collimation is what's needed here. But I "ain't got no" collimator, or even the proper standard info to cook up one. I'm trying to use camera bodies to find the correct scale setting on the lens. You would think that with enough camera bodies, you could get your infinity stop close. But not so far. It's all over the place. I haven't even started experimenting with seeing how far apart multiple backs are. If that turns out to be the same nightmare as I've had with just the infinity stop on the lens agreeing with half a dozen different bodies, then I'm going to conclude that Hasselblads just aren't as divinely standard perfect as the popular reputation would have one believe.

 

[Mark Crabtree]

I think you are still missing my point. You keep saying the bodies are off. Do you mean that they don't focus the same on the film, or with the viewing screen. My experience was that the viewing screens were sometimes off compared to the film. I personally did not encounter situations where the film and viewfinder focus agreed but the collimation seemed off for the body.

 

[henry finley]

I don't know what's off. The camera bodies with screens do no agree with each other at the screen. I haven't done any testing with respect to the film or film plane. What I mean is that when I set the infinity stop to come up right at the screen on one body, it's wrong on another body., and I have to re-set the lens infinity stop point for another body AT THE SCREEN, not the film. I have no idea at this point if the screens agree with the film. I'm just trying to get the lens to come up the same from one body to another in the viewfinder.
If Hasselblad changed the 500C and EL to be a CM or ELM, then certainly there should be no difference between whatever screen you drop in it. I can take a Nikkormat, or an F2 and switch screens all day long, and infinity is perfect on all of them.

 

[epatsellis]

Henry,
The lens flange to back distance is critical (71.40mm +-.03mm, or about .001), and adjustable (as noted above).

Do you have a copy of the Hassy service manuals? The procedure outlined in them is pretty clear, and without the proper fixture (V-2229), or a reasonably accurate facsimile, you can't get it right. Mirror angle is then adjusted with a sighting tube, and then the screen position is adjusted as well (using a screen adpater (V-4705) an illuminated fixture in the front bayonet (V-4151), and finally a microscope fitted with V-4705 adapter. Then, sighting through the microscope, screen height is adjusted.

Needless to say, the likelyhood of getting it right without the proper tools and jigs is about .0000001%. Any time the housing is removed, at the very least the length needs to be checked and adjusted.

I've skipped a bunch related to release geartrain adjustment, cocking lever position adjustment, etc. as well as the back adjustments.

If you don't have a copy of the manuals, they're readily available. I'm assuming (always a risk) that you are familiar with the distance that the helical assembly needs to be set to before assembly, as each lens has a different distance and is set by rotating the mounts against each other.

Any of the issues you noted are quite likely due to body (mis)adjustments as well as lens collimation issues. A lens to the short side of proper ffl will focus just fine at infinity on a long body, or one that the screen is high on, or with the mirror being out of adjustment. Put that same lens on a correct body and it will focus past infinty. Without the proper tools and not knowing if a body or lens is within spec makes any observations moot. Hasselblads are complex beasts, I prefer to stick to my RB's personally.

erie

 

[henry finley]

OK--you've come up with the answers I was expecting. Yes, I have the 503 service manual that is available free online, which applies to the 500c and CM also. I'm aware of the measurements and the fixtures required, which I could never afford. Not to mention the 10 billion pieces guys like Odess and the other factory guys have done, as CERTIFIED techs.
So... all these old bodies Ive been fooling with are obviously just out-of-whack EBAY junk, I concede. As many machines of all kinds I've worked on in my day, I was usually able to find some sort of bolt-together standard of reasonable accuracy. Apparently these Hasselblads just aren't going to allow that. I'm just having a hard time swallowing that mirror stops have gotten bent, screen pegs have gotten off, body screws have shifted, and all the other little age-related issues have added up to give the frustratingly low level of available accuracy I can achieve at the simple bolt-together level I'm doing. This is pitiful. If the used Hasselblads out there all need to be bought on an EBAY auction, and sent off to a factory tech for the high-dollar treatment, then they're obviously just useless junk, and I should just stick with the Graflexes and such.

 

[Paul Goutiere]

This is pitiful. If the used Hasselblads out there all need to be bought on an EBAY auction, and sent off to a factory tech for the high-dollar treatment, then they're obviously just useless junk, and I should just stick with the Graflexes and such.

I think there are a few of us here that will agree on this point; Get rid of them useless Hassys....immediately.

Send me a PM and I'll give you an address where you can dispose of this landfill properly, yes I'll even pay the postage.

 

[henry finley]

That's OK--wouldn't want to put you out. I'll just gather 'em all up and wait till Jan 2, and go throw 'em off the fiscal cliff.

 

[lxdude]

Henry,
I'm glad epatsellis came on to explain all that it takes. I had an idea what it takes, but little actual knowledge and no experience. But I'll say that if my Bronicas can all agree with each other, so can your Hasselblads.
I used to work as a machinist, and much of it in production machine setup, especially automatic screw machines. I used to describe your dilemma to trainees as "You're chasing yourself around the machine-you're never going to catch up. You have to establish your base dimensions and work from those."

 

[lxdude]

Regarding the adjusting with a mallet and fixture, to anyone surprised by that. The fixture establishes the desired dimension precisely. Giving a good strong whack puts the piece being moved into solid and complete contact with the fixture and overcomes the elasticity of the metal and resistance to being moved. The flange distance is established in a way that is conclusive and repeatable. Tapping would not produce results as precise.

 

[brucemuir]

Don't blame the design because you don't have the correct tools…sheesh.

 

[henry finley]

Had I not had respect for the name, the reputation, the actual camera, and the guys who work on them, I doubt I would have even started the thread at all. My initial opinion the first time I ever took one apart, always stuck with me. I thought it was simplistic. Ever see the inside of an EL? There's nothing in it. A few parts that look like they could have been inside a 25 dollar Kodak Instamatic. But you then see the ingenious kind of simplicity. It can't NOT work. And probably will work the same way in 300 years. I'm determined to chase down and kill a rat. The exact place where I should turn the focus-knob to perfect infinity before I screw down the position and button the lens up. And so far, at least a half dozen untampered bodies are not letting me find the common point. It just didn't make sense. So I got on the computer and made a big deal of it. You know why? Because I've been doing these sorts of hobbies for years and I've always found that other guys like that out there are the A-OK. Radio guys, model airplane guys, camera guys. It's just plain good fellowship. Thanks, friends. HTF

 

[Douglas Fairbank]

I have come a bit late in the discussion but I can assure you Henry that all your Hasselblad bodies can be set to be the same focus. Using the aforementioned V2229 tool the body length is set then the mirror alignment then the screen alignment. In my experience, 38 years with Hasselblad in the UK, the main cause of disparity between the what you see and what the film sees is expired mirror cushions, the small foam pads that support the mirror as the frame flexes. Quick answers to other points raised here are, yes the film gate can be part of the problem and that is adjusted with tool V4548, viewing screens can get damaged so it is possible that two screens may focus differently but its not common. Just for the record the body settings are the same for film and digital.

 

[E. von Hoegh]

Thanks. I've got an HQ110 Hammarlund I've had for 30 years--that's all I need. I've already bought, fixed up, and sent out 2 HQ 180's out of here. Terrific radios, but for the ham bands, it's kinda tedious to have to do the crystal oscillator every time you switch bands.

Then get an old R390, or an R388 and replace the seven deadly capacitors... after you rebuild the PTO. These radios are designed to hold calibration, and will with proper servicing.

I don't really understand what the issue is here. You talk about working on precision intruments, but reccomend a hammer as a useful tool - I think this is a clue to the problem.
I thing somewhere along the line, you're losing the "original zero". I think you need to look at your approach and methodology. Not to mention getting the correct service information and tools.
As for the calibration oscillator in the Hammerlunches, it's there as a convenience to spot frequencies accurately and should be used in conjunction with an infallible reference such as WWV. You are calibrating the crystal oscillator beforehand, right? Because I've been working on these things since about 1975, and I can tell you you are expecting way too much from the Hammarlunds - they just weren't intended or deisigned and constructed to hold calibration the way you expect them to. Not to mention the age of the things.

 

[Paul Goutiere]

Because I've been working on these things since about 1975, and I can tell you you are expecting way too much from the Hammarlunds - they just weren't intended or deisigned and constructed to hold calibration the way you expect them to. Not to mention the age of the things.

Working on a communications receiver, built in the United States around wartime, might be a bit different than working on a camera. The skill set should be quite a bit different.
Alignment tools are plentiful and relatively generic for old communications receivers. They can be bought inexpensively but Hassy tools.....I have no idea.

 

[E. von Hoegh]

Working on a communications receiver, built in the United States around wartime, might be a bit different than working on a camera. The skill set should be quite a bit different.
Alignment tools are plentiful and relatively generic for old communications receivers. They can be bought inexpensively but Hassy tools.....I have no idea.

I'm well aware that the skill sets to service cameras and radios are not identical. But basic troubleshooting skills aren't specific to any one thing, nor is craftsmanship.

My point was that the OP's approach and technique is flawed in both areas. I don't have enough experience with Hasselblads to point out the details of his errors in that particular area, however I do have sufficient experience with older electronics to point out his errors and unrealistic expectations in that area.

As for alignment tools, they're generic as you point out. So are basic alignment procedures. But the OP is confounding alignment and calibration in one of his posts - a clue to his problems with the cameras.

 

[Paul Goutiere]

My point was that the OP's approach and technique is flawed in both areas. I don't have enough experience with Hasselblads to point out the details of his errors in that particular area, however I do have sufficient experience with older electronics to point out his errors and unrealistic expectations in that area.

As for alignment tools, they're generic as you point out. So are basic alignment procedures. But the OP is confounding alignment and calibration in one of his posts - a clue to his problems with the cameras.

I wasn't arguing the point, and I agree with you entirely. I think I might have addressed the comment to the OP.

I like old communications radios as well. I'm particularly fond of my Hallicrafters SX24 and a strange old Collins a R-105a/ARR-15 I've had for a few years now. The Halli has to be recapped entirely but the Collins is still completely within spec as far as I can tell.

But these things aren't like working on a camera. Working on my SX24 is like working on plumbing, whereas working on a camera is like working on a ............camera!

 

[E. von Hoegh]

I wasn't arguing the point, and I agree with you entirely. I think I might have addressed the comment to the OP.
I like old communications radios as well. I'm particularly fond of my Hallicrafters SX24 and a strange old Collins a R-105a/ARR-15 I've had for a few years now. The Halli has to be recapped entirely but the Collins is still completely within spec as far as I can tell.

But these things aren't like working on a camera. Working on my SX24 is like working on plumbing, whereas working on a camera is like working on a ............camera!

Ah, OK. My mistake.

It never ceases to amaze me how stable some of those old Collins' designs were/are. Isn't the arr-15 an aircraft reciever using a dynamotor for B+?

 

[lxdude]

. Isn't the arr-15 an aircraft reciever using a dynamotor for B+?

Proving once again that Morse isn't the only code radio guys communicate in.. :confused:

 

[lxdude]

You talk about working on precision intruments, but reccomend a hammer as a useful tool - I think this is a clue to the problem.

Recall the previous post about a repairer using a wooden mallet to give the thing a whack.
A hammer (actually a mallet, to be specific) is sometimes the right thing- if used properly. As a machinst, I frequently used lead or brass hammers to bump various holding fixtures into precise position, usually with a dial indicator, or for really high precision, gauge blocks. Also I used them to seat workpieces in or on fixtures, or to position pieces which were to be clamped directly onto the machine like a milling machine's worktable or a faceplate on a lathe. Some mighty big pieces can be positioned to a tenth of a thou with a good whack in the right place. The proper size and material type of mallet is important.

My understanding of the Hasselblad method is it requires use of what amounts to a custom gauge block, to which the distance is set by use of the mallet. The momentarily high force generated ensures proper and repeatable "seating".

 

[E. von Hoegh]

Proving once again that Morse isn't the only code radio guys communicate in.. :confused:

Dynamotor = Dynamo (generator) driven by an electric motor, a common method of providing plate voltage (B+) on older aircraft and marine radio sets.

 

[E. von Hoegh]

Recall the previous post about a repairer using a wooden mallet to give the thing a whack. A hammer or mallet is sometimes the right thing- if used properly. As a machinst, I frequently used lead or brass hammers to bump various holding fixtures into precise position, usually with a dial indicator, or for really high precision, gauge blocks. Also I used them to seat workpieces in or on fixtures, or to position pieces which were to be clamped directly onto the machine like a milling machine's worktable or a faceplate on a lathe. Some mighty big pieces can be positioned to a tenth of a thou with a good whack in the right place. The proper size and type of hammer (actually a mallet, to be specific) is important.

My understanding of the Hasselblad method is it requires use of what amount to a custom gauge block, to which the distance is set by use of the mallet. The momentarily high force generated ensures proper and repeatable "seating".

Ah, but that's the key isn't it? I'm a machinist as well, but I'm also a watchmaker - I have very small hammers, as small as 1/8 ounce. They're used only for setting tiny rivets though, such as those on a fusee chain. And yes, a hammer is sometimes the only correct tool. It takes years of experience to know when though.

 

[Paul Goutiere]

Ah, OK. My mistake.

It never ceases to amaze me how stable some of those old Collins' designs were/are. Isn't the arr-15 an aircraft reciever using a dynamotor for B+?

The radio is from about 1948. Mine was made by Collins for a submarine tracker aircraft. The thing is no where as utterly cool as a Hallicrafters SX28 but has it's qualities such as
ten frequency presets.

When I acquired the radio it came without a dynamotor and I built a external power supply for it. The B+ was easy, as I recall about 250 volts and 100 or so milliamps.
The filaments are wired in series so they could run off 24 volts, like the input to the dynamotor, and took about 2 amps I think, but the tuning motor draws a good 10 amps at 24 volts during start up
and would cause all sorts of problems.

After an hour of operation this thing is "dead nuts" as a older friend used the term.

 

[E. von Hoegh]

The radio is from about 1948. Mine was made by Collins for a submarine tracker aircraft. The thing is no where as utterly cool as a Hallicrafters SX28 but has it's qualities such as
ten frequency presets.

When I acquired the radio it came without a dynamotor and I built a external power supply for it. The B+ was easy, as I recall about 250 volts and 100 or so milliamps.
The filaments are wired in series so they could run off 24 volts, like the input to the dynamotor, and took about 2 amps I think, but the tuning motor draws a good 10 amps at 24 volts during start up
and would cause all sorts of problems.

After an hour of operation this thing is "dead nuts" as a older friend used the term.

There's a companion transmitter to that, also electrically/remotely tuned. There's an "Old Military Net" on (IIRC) Sunday mornings on the 75m ham band, guys are using these sets still. Some are even using the original carbon mikes, which give an "interesting" sound quality.
My main serious SW listening reciever is a Collins R-388. I can tune a sideband signal with the BFO, shut the set off for a day, turn it on and after about 30 minutes it's right back on top of the signal. They just amaze me.