Does the Hasselblad A24 Film Magazine give better quality photos than the A12 magazine?

[ken_wayne1]

I was recently reading through a thread on photo.net: <A HREF="http://www.photo.net/medium-format-photography-

forum/00RZVy">here</A>

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Poster Marek Fogiel gave a link to a photographer <A HREF="http://www.horolezec.cz/">here</A> named Ladislav

Kamarad.

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He is definitely as meticulous as anyone I have ever seen in regard to his demand for quality. I noted his writings on A12

vs. A24 magazines and I copied and pasted it here. I would like for anyone else to critique and debate what he wrote on

<A

HREF="( http://www.horolezec.cz/blog-

engl/index.php?action=item&itemid=5)">this</A> page.

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Here is what he wrote:

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"The common deviation from the ideal focal plane immediately after the 120 film rewind (pull on the camera) is usually

around 0.2 mm and it increases over time by more than 0.5 mm and this is without speculating about extreme conditions as

high humidity or temperatures well below freezing point - under these conditions it is "fuck it all :-).

This issue is well demonstrated by the Zeiss study - the Document is available for download <A

HREF="http://www.horolezec.cz/blog/media/1/Image/vac_kazety/Some_facts_about_film_flatness.doc">here</A>.

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In simplified way, it can be stated that: "average error" of roll film 120 with the underlay paper base is typically in the

magnitude of 350 microns (0.35 mm) and for roll film 220 (without the paper base) it is about 200 microns (0.2 mm). My

own measurements correspond very well with another study, available for download <A

HREF="http://www.horolezec.cz/blog/media/1/Image/vac_kazety/120_vs_220_films.doc">here</A>.

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Based on this knowledge, it is very hard to understand why roll films 220 are not used exclusively, when if compared to 120

films it has a lot of advantages and almost double precision of the film position, because it is not forced away by the

absolutely needless underlying paper. Thanks to ignorance and pointless fear of the "reflexes from the film pressure plate",

scratches, or light intrusion during the film exchange, the 220 roll film is difficult to buy on the European market at all.

Nevertheless, this material itself does not solve the problem, but only reduces it a little bit. However, it is essential material

for the operation of the underpressure magazines (backs) as described hereinafter."

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I'd like to hear the experience of others on this and whether or not most would agree with this gentleman. A24 magazines

sell for pennies these days so will photographers be better served regarding quality to buy A24 magazines and shoot 220

film or is the quality difference so miniscule and the choices among 220 film so minimal that most here would balk at using

A24's over A12's?

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Thanks in advance,

Ken

[q.g._de_bakker]

Consider this:<br>until Zeiss produced a study (produced - take note - by Zeiss' Strategic Marketing Department),

claiming (!) that 220 film lies flatter than 120 film, in an attempt to promote the Contax (Zeiss) vacuum backs (yes,

the Strategic Marketing Department...), which only work with 220 film, absolutely nobody at all ever complained

about the fact that 120 film would be less flat than 220 film, because absolutely nobody ever had noticed that it

was.<br><br>So yes: "the quality difference [is] so miniscule and the choices among 220 film

so minimal that most here would balk at using A24's over A12's?" is on the right track.<br>That there is a difference

at all (not just insignificant variance) has yet to be shown conclusively.<br>;-)

[q.g._de_bakker]

P.S.<br><br>The Contax vacuum backs were a huge failure. Nobody bought one. Nobody felt there was a need.<br>;-)

[david_henderson]

This is an old issue that seemed to get a lot of airtime about 5-8 years ago. A few people - one of whom was

employed by Zeiss ( who had apparently carried out research) seemed for a while to promote a cause that 220 film

lay flatter. The debate seemed to revolve around measuring tiny deviations with the film held in medium format

backs- in short, the theory of it. There didn't appear to be much looking at photographs involved.

 

Now, I've used 120 and 220 films in parallel for more than ten years. I look at my photographs with a decent

aspherical loupe; project them to abour 5 feet across and have prints made up to 36" across. I have not seen any

variation in sharpness that I can put down to the use of 120 or 220 film. Mind you, I don't examine my slides with a

microscope, and I don't carry out "scientific reasearch". I only look at my photographs with a somewhat critical

eye. I also tend to use a camera somewhat stopped down which would alleviate or materially eliminate the issue

anyway. I think its a dead and irrelevant issue.

 

Also in the "dead" box is the argument, promoted by the same people, that leaving the film partly used in the

camera for longer than a few minutes caused kinks that might produce unflatness and so unsharpness. This one

even got to the point that people were indicating which frame of the roll should be used for the most critical shots!

 

All of which goes to show, to me in any case, that there's a big difference between something happening and

whether it matters.

 

I like 220 film. Its a little harder to look after but its very convenient, and on a long trip carrying much of your film in

220 reduces the load as well as sending you out for the day more confident that you're not going to need to change

films or backs right at the critical point of a magnificent dawn. Of course the most significant issue is whether the

films you like are available in 220- many are not. But its a convenience thing not an image quality thing or a price

thing - indeed the cost per frame can be a little more.

[brucecahn]

Have used both extensively. Never saw a difference.

[thomas_wilson1]

I use both, but use the 24's most of the time. I do quite a bit of shooting mid-river from partially submerged tripods and find changing backs to be a risky proposition at best. I have never noticed a difference in sharpness between the two. I do see glass negative carriers, proper enlarger alignment, and preheating of negatives, as absolutely critical to print quality.

[dweezil]

I have a hard time getting in to that as the backing paper is sitting behind the film and the pressure plate is pushing the film against the film rails. So the thing really determining the distance is the thickness of the emulsion. and the whether or not the rails are at the correct distance for the lens. All other things like the backing paper and so on only add to the amount pressure with which the film is pressed against the film rails.

 

Besides, the 220 film being flatter is all good and well, but as far as I know there is no black and white220 film available.

 

Having no film means having no picture, means having no flatness and finally no sharpness whatsoever.

[leicaglow]

This guy takes the issue so seriously he built his own vacuum back for his Hasselblad system. I've not found it that big of a problem, plus, I can think of other ways the process can be flawed and induce error into the sharpness of an image, besides the back: http://www.horolezec.cz/technique.htm

[colin_elliott]

"Nobody bought one"

 

Q.G. I think that is a vast overstatement.

I have at least one and use it almost exclusively.

 

I'd be surprised if Marc (Williams) when he was a Contax 645 user didn't have some too.

 

What statistics do you have that show it as a huge failure? I don't think the Contax vacuum back was a Zeiss product, but rather a Kyocera made item..

[q.g._de_bakker]

Colin,<br><br>Statistics? You just tell me where i can go to buy one...<br>The vacuum back was indeed a Kyocera

product. The Contax camera was too. That is: it was built by Kyocera. The Contax name was and is Zeiss', and the

Contax camera only existed as a vehicle to sell Zeiss lenses. So Zeiss had a vested interest in promoting sales of

the thing.<br><br>Not that the Contax was a bad camera. On the contrary.<br>But this whole 220 vs 120 thingy was

a marketing thing. A "Strategic Marketing" thing. No more.<br><br>Now, you have one of those vacuum backs,

which you have used extensively. I know that it is a difficult question, but was it worth it? Did you notice any

difference? ;-)

[stephen_pitts]

Ken,

 

I hate to be the person to argue the other side here, but I know that internally at Hasselblad they also acknowledged that the A24 produced better pictures (slightly) than the A12 particularly with very wide angle lenses that were shot almost wide open (as I recall). However, the biggest and most important step to make is to make sure that you wind the film through two frames before taking pictures again if you have left the film in the camera for something like over 45 minutes (otherwise the part of the film that sat on the rollers lifts the film a bit more from the flat plate). Anyhow, the advantage of the A12 in black & white is that you waste less film if you are shooting with the zone system (which the E12CC is ideal for with a 205 camera by the way).

 

Cheers,

 

Steve

[stephen_pitts]

By the way, I hugely admire Ladislav Kamarad for the phenomenal dedication and professional skill that he has

demonstrated. I'm quite surprised at the use of the flexbody with the 350SA by the way -- I would be surprised that it

would be of very much use, but no doubt better for controlling the plane of focus in some critical shots -- thats

dedicated (because its quite tedious to say the least)! But the shot is the shot. Cheers, Steve

[brucecahn]

To Thomas Wilson: I have never heard of pre-heating the negatives. Will you explain please.

[thomas_wilson1]

Bruce, pre-heating negatives is a technique that can and usually does make a big difference in the sharpness of

your print. When you place your negative in the carrier and then the enlarger, you may assume that the negative

and carrier are at room temperature. With the enlarger lamp on for focus, cropping, or exposure, the negative and

carrier will heat up and expand.

 

This is more pronounced in condenser type enlargers, but I can see the effects easily printing 6x6 negatives on

my Super Chromega D. Bridges have expansion joints to relieve the pressure and keep the pavement from buckling

from changes in temperature. The same principle applies here, only with no expansion joints.

 

Depending on your technique, you may find that you inadvertently pre-heat your negatives without realizing it.

You can try a simple test. Load a negative into a cold enlarger and focus on the grain. Leave the enlarger on for

5 or 10 minutes and recheck the focus. If you try this with a 4x5 negative and condenser head, you may even hear

the "Pop" from the negative expanding from the heat.

[wai_leong_lee]

Use glass carriers, end of story.

[tarashnat]

Q,

 

Actually, there was one group of people that were discussing and hand producing vacuum and gas purge backs back before Zeiss—

astrophotographers. This is the one group where the subject matter was such and exposures long enough where the retention of film

flatness over the course of a multi-hour exposure during which environmental conditions change quite dramatically over time was an issue

for some. This same group would also bake their films in a forming gas to improve its sensitivity. And even then, it was a matter of eeking

those last few percentage points of performance.

[q.g._de_bakker]

Sure. I have Hasselblad 70 mm vacuum backs too.<br><img src="http://home.tiscali.nl/qnu/images/Vac.jpg"><br>Doesn't mean though, just because you can use 220 film in a vacuum back, while you can't use 120 film in the same, that 220 film is flatter than 120 film.

[charles_mason]

Anyone know how the Holga stacked up in this comparison--of course it is ONLY available in 120. Hey, maybe that means the Holga factory doesn't buy into this flatness comparison of 120 vs. 220, as for sure they'd have made their models in 220 only!

[colin_elliott]

Q.G.

You can buy one right now on ebay.

 

Do I notice a difference? Haven't done any comparison tests,but I just like to maximise all controllable aspects of my shooting and minimise any quality reducing possibilities.

 

Was it worth it? Absolutely, Paid same price as I would for a 120/220 back

[stephen_pitts]

Colin, don't see it on ebay?

 

Q.G., would be interesting if you noticed any differences?

 

Cheers,

 

Steve

[q.g._de_bakker]

Colin,<br><br>eBay. Yes... ;-)<br><br>Stephen,<br><br>No. Never (noticed a difference).

[brucecahn]

Thanks Thomas. I mostly contact print, and if not use a glass carrier for the larger negatives. I do know about the "pop" someone mentioned. When I shot a lot of film for enlargement the pop meant it was time to reset the negative in the carrier.

[colin_elliott]

Stephen,

Try 250332676507 and 250329364114

[stephen_pitts]

Sorry guys,

 

I'm an idiot. I thought that Hasselblad had produced such a 220 back (which I had never seen).

 

Anyhow, there is a very cool guy who shoots a Linhof 4x5 with a vacuum driven roll back and does some real action photography with it (I think the set-up was originally used for aerial reconnaisance). Sinar as well had very special backs for the larger film formats to hold them in place (not vacuum driven though). 6x6 is probably right on the cusp of where flatness can become a material issue. In fact, as I recall, while Hasselblad carefully minimized the tolerances by matching every filmback's cassette to its holder, the actual design itself -- with the film rolling back on itself -- necessitates the advancing of the film as I described above (if you let the film sit in the cassette for a little while). Rollei's design was much better in this regard. Enough said.

 

Cheers,

 

Steve

[q.g._de_bakker]

No, Stephen,<br><br>This never was an issue until Zeiss started their Contax vacuum back promotion.<br>Enough said.