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  1. #11
    Helinophoto's Avatar
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    I agitate like this, spinning while rotating. I vary the speed and intensity (and number of up-and-around agitations) to control contrast.
    Seems like a very good way to make sure the whole film is evenly developed:
    http://youtu.be/vKVKOnexIY0?t=1m44s (starting at 1 min 44 sec)
    -
    "Nice picture, you must have an amazing camera."
    Visit my photography blog at: http://helino-photo.blogspot.com

  2. #12
    Photo Engineer's Avatar
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    A prewet allows film to imbibe developer more evenly and it helps reduce pinholes caused by air bubbles.

    In the OP, one of the pictures shows an indication of bromide drag along the edges. You can see streaks upward from the bottom in a regular pattern that is typical of bromide drag. The other frame shows a streak that looks like uneven wetting of the film with developer.

    PE

  3. #13

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    Quote Originally Posted by Photo Engineer View Post
    A prewet allows film to imbibe developer more evenly and it helps reduce pinholes caused by air bubbles.

    In the OP, one of the pictures shows an indication of bromide drag along the edges. You can see streaks upward from the bottom in a regular pattern that is typical of bromide drag. The other frame shows a streak that looks like uneven wetting of the film with developer.

    PE
    Wonder why the rest of the world of photographers stopped pre-wetting the film in the 1930-ies?
    As they describe, it was because of intermittent problems with uneven developement, but please go on to reccomend a long forgotten and not needed procedure that is known to introduce problems.

    Why the H... use pre-wetting when it isn't needed and is known to cause problems?

    It is like saying that bromide drag cannot occur with rodinal since there is no bromide ions in the developer. Guess what, when the developer starts working on the emulsion, bromide is released into the developer, and the acitivity of p-aminophenol IS reduced by bromide. A lot more than metol or phenidone. Because of that bromide drag is often seen on film developed in rodinal or R09 when there is insufficient agitation.

    But, please do as you wish. You may even use pre-wetting with two-bath developers if you wish, but the result will be unuseable.

  4. #14
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    Kodak instruction manuals showed use of a prewet into the 50s. I posted the sequence and photos from the manual here about 2 years ago or so.

    Jobo recommends a prewet.

    There is a very excellent prewet experiment conducted and posted here on APUG.

    PE

  5. #15

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    Quote Originally Posted by Photo Engineer View Post
    Kodak instruction manuals showed use of a prewet into the 50s. I posted the sequence and photos from the manual here about 2 years ago or so.

    Jobo recommends a prewet.

    There is a very excellent prewet experiment conducted and posted here on APUG.

    PE
    As you wish.
    I still wonder why most photograpers warned against it from the 1930's and onwards.

  6. #16

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    Quote Originally Posted by Tronds View Post
    As you wish.
    I still wonder why most photograpers warned against it from the 1930's and onwards.
    hi tronds

    some people pre wet, some don't,
    some use water instead of stop bath, some don't

    there are as many ways to process film as there are people using a camera

    does it really matter?

    john

  7. #17

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    Quote Originally Posted by jnanian View Post
    hi tronds

    some people pre wet, some don't,
    some use water instead of stop bath, some don't

    there are as many ways to process film as there are people using a camera

    does it really matter?

    john
    Yes, when they use methods that are known to cause problems, AND they do in fact have problems.
    Otherwise, no.
    The pre-wetting was abandoned nearly 100 years ago because they found it to cause uneven developing. It isn't neccessary in any way, so why introduce a moment that may cause problems? Forget it! It isn't neccessary, AND it is known to cause problems from time to time.

    It its like closing your eyes for a second or two when you are driving your car and you approach an intersection. It isn't neccessary and it may cause problems bigtime. Why do you want do something like that?

  8. #18

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    With Ilford delta films (I don't know about Foma), I often see a fair amount of what looks like foam when I pour out the developer if I don't presoak. So, for that reason alone, I use a presoak every time with 120 film. (No chance of photoflo contamination, separate containers and off the reel by then). But your images have a bubble like quality to my eyes, is it possible you have photoflo from the last film on the reels or tank before developing the new rolls? Do you see any foam when pouring out the developer?
    If not, I would still keep the presoak, go for at least a minute after pouring in developer, then agitate for at least 15 seconds each time, to ensure complete exchange over all the film. I also have measured the amount of liquid necessary to cover both reels, and use just 20cc more than that, just to ensure room in the tank for the chems to move.
    Also, as Thomas indicates, you can go for 2 - 3 minutes between agitation cycles with 120 film, as long as the cycle itself is long enough to get good movement. It may take awhile to find the right cycle combination for the right contrast.

  9. #19

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    Quote Originally Posted by George Collier View Post
    With Ilford delta films (I don't know about Foma), I often see a fair amount of what looks like foam when I pour out the developer if I don't presoak. So, for that reason alone, I use a presoak every time with 120 film. (No chance of photoflo contamination, separate containers and off the reel by then). But your images have a bubble like quality to my eyes, is it possible you have photoflo from the last film on the reels or tank before developing the new rolls? Do you see any foam when pouring out the developer?
    If not, I would still keep the presoak, go for at least a minute after pouring in developer, then agitate for at least 15 seconds each time, to ensure complete exchange over all the film. I also have measured the amount of liquid necessary to cover both reels, and use just 20cc more than that, just to ensure room in the tank for the chems to move.
    Also, as Thomas indicates, you can go for 2 - 3 minutes between agitation cycles with 120 film, as long as the cycle itself is long enough to get good movement. It may take awhile to find the right cycle combination for the right contrast.
    Any photoflo left in teh tank will help the developer wet the film more evenly when used without pre-wetting.
    I sometimes have a bit of photoflo or equvalent left in the tank when developng films and have observed a bit of foaming when emtying the tank.
    Never, NEVER had any problems with uneven developing because of this though.
    I have had uneven developing in two-bath developers because unsufficient agitation though, but that is about the same problem you can run into with pre-wetting.
    Continous agitation will solve the problem, but with standard one bath developers, loosing the pre-wetting will also solve most of these problems unless agitation is almost non existent.

    But as I have said earlier, do as you wish, but don't complain if you get shitty results.

  10. #20
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    Photo Flo can be removed by a hot water wash and scrubbing with a brush. I have never had carryover when using this method of cleaning equipment.

    That said, if Photo Flo is carried back to the developer it is due to poor cleaning of equipment and when PF dries down it forms a sticky gunk. This gunk when rewetted by developer or any water can form sluglike particles in the water which can be deposited on the film's surface and which can cause spots to appear.

    There are dozens of reports on this on APUG here. So, it is wise to remove all PF from your equipment by a hot water scrub after use.

    As for a prewet, again I direct you to the test here on APUG. I believe it was run by Greg Davis, but not sure now. As for a prewet being a no no, I have never heard this, and in fact have read the opposite for years and years!

    But, in the final analysis, use what works for you.

    PE

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