When exactly do I add Photoflo in process?

Discussion in 'Film and Processing' started by houstonphotographics, Jul 8, 2014.

  1. Hi All,
    I recently just got back into developing my own b/w films at home. Strictly 120 only for now. I have read several articles on Kodak Photoflo and water spot removal. I currently am not using this, but that will change shortly. My process is;
    Develop film as normal
    Stop
    Fix
    Rinse (cold running tap water for about 10mins)
    The last step above is where I am confused. Do I add my Photoflo (pre mixed from one gallon stock solution) AFTER I do my standard 10min rinse? I have also read that users fill the tank up with the photoflo solution and slosh the film reel around in this for 30 seconds, up to 1 min, then hang film strip to dry as is.
    I just want to get the information straight as best as possible so I can improve the quality of my negatives. FYI; my water is extremely hard, and spotting is a problem. I do finger squeegy as well as use a rubber squeege but I think that is not helping my situation. Many thanks , and I apologize if this has been addressed before. Cheers!
     
  2. SCL

    SCL

    My technique for many years has been after the final wash to immerse the film in the diluted photoflo solution for 30 sec. and hang to dry. I personally lightly finger squeegee. I also have hard water, so for the photoflo solution I use distilled water and have never had a problem with water spotting.
     
  3. If you mix Photo-Flo and keep it you will find a jelly/slime in it you need to filter out. best to mix as needed. Soak washed film for 30 seconds in dilute Photo-Flo then hang to dry . Chris
     
  4. I've always just left a bit of water in the tank or tray following the rinse, used an eyedropper to add a couple drops of concentrated Photoflo to the remaining rinse water, then stirred it up and let the film soak for about a minute. I'll usually move the film around or in and out a few times during the soaking process.
     
  5. Hi Kenneth,
    Film consists of a coat of highly purified gelatin on a flexible base. The light sensitive goodies are imbedded in the gelatin which acts as a glue to hold everything to the base. Gelatin is used because it swells when wet allowing the fluids of the process to percolate freely within the structure. The last major step is the fixer. This solution contains sulfur and if not washed out, the sulfur attacks the silver based image and tarnishes it. We wash for 20 to 30 minutes to ensure all the fixer is rinsed out completely. An alternate is to use a hypo (nickname for fixer) clearing agent. These are special salts that help flush out fixer. A hypo clearing bath followed by 5 minute wash in running water is ample.

    The key drying technique is to use a final rinse fluid free of foreign particles. Highly filtered water is OK many use distilled or deionized bottled water. Now water tends to bead on the surface of the film will be in the form of localized water droplets that dot the film’s surface. As film dries the swelled gelatin shrinks. If water droplets are present, they retard shrinkage in a localized way. The film dries with uneven shrinkage and the result is water-marks that are likely irreversible. The counter measure is a wetting agent rinse bath. 30 seconds soak in PhotoFlow or equivalent does the trick. This is a sequestrate that breaks the surface tension of water. The water now sheets instead of beads. Many now sponge the film or squeeze to ensure water drops are absent. I run the film through two fingers wet with the rinse.
     
  6. After the last rinse, with the film still on the reel, I put about quarter a cap full of photo-flo into the tank, then put the reel back in. The normal dilution is 1:200, so that might even be too much.
    It comes in a 16 ounce bottle, so it takes a long time to use up, even without reusing it.
    Then, after it is hanging from a film clip on a nail, I run two fingers dipped in the tank down the film, not squeezing on the film, but spaced apart vertically with the film in between.
     
  7. One or two drops per reel in the tank with the final rinse, usually with distilled water, after the Ilford in-tank wash method.
    I don't squeegee or use my fingers - my skin is too rough. I just hang the negative strip diagonally to dry. Any residual water gravitates to the lowest single edge and drips off the single lowest corner. Any residue will be confined to the film margins and usually won't affect the exposed frame, even with narrow rebates on medium format film.
     
  8. lwg

    lwg

    I do it the same as the others here, putting a few drops into the final rinse. No squeegee. If your water is really hard I would do the final rinse with distilled water and photoflo. I don't reuse it beyond one session. In other words i will rinse several films in it in one day, but do not keep longer than that since in theory it can grow mold if any gelatin gets into the water. And it's very cheap.
     
  9. An alternative method, which is the one I use, is to move the film through a clear glass or plastic tray of Photoflo after the final wash by first attaching a clip at one end of the film after removal from spool and hold the film vertically in a "U" shape then slowly run the film through the solution avoiding touching the bottom of the tray. I do this in addition to the normal Photoflo treatment in the tank. The tray method allows inspection of the fluid and any bubbles as the film is being slowly worked through, and a rate of movement can be established to ensure uniform fluid across the whole film surface eliminating bubbles as you go by reversing up the film then going forward again
    I also use Lex's method of diagonally draining Photoflo solution but only till the excess fluid reaches the edge then wipe the edge and only the edge with my finger tips. After, hang to dry perpendicular with the clip still on end of film
    Interestingly, I'm still using Photoflo purchased 30 years ago and it's still ok but must be mixed 1:200 to make certain that milky sediment doesn't form, even Kodak advise on this one. Too much Photoflo can cause problems
     
  10. James G. Dainis

    James G. Dainis Moderator

    Ken, Good. That is the way I do it, holding the film in a U curve and dipping it through a wide mouth jar. I like when I can see the bubbles coming off or not even forming.
     
  11. Reminds me, when I first knew about Photo-Flo 40 years ago, I read that Kodak also makes a Photo-Flo 2100, that should be diluted 2100:1, and only comes in gallon bottles. That was when Photo-Flo 200 came in 4oz bottles, but now I only see 16oz.
     

Share This Page