Prewash?

[jbaylon]

Does anyone prewash before developing?

I'm completely new to developing B&W and along with everything I can find on the web I have been reading Ansel Adams' The Negative. He mentions prewashing, but beyond that I have only come across it with recommendations for Rollei R3 film. Adams explains how it softens the emultion for development. Are there any reasons why it isn't prevalent?

In other words, what are the reasons for not prewashing?

Thanks for sharing your knowledge
Jay

[Greg Winterflood]

Jay - I'm new too and have wondered if prewashing is necessary. It seems that prewashing can remove anti-halation dyes from the emulsion. Apparently, if you prewash in water and pour out the water it will be coloured with whatever dye was used. I've also read that if you use developer first up - without prewashing - that the used developer is not stained with the colour of the dye. I'll be interested to see the answer to your question from someone who knows the answer. Especially with regard to whether the dye has an effect on the final 'colour' of the B&W negative. That is, I am wondering if any dye left in the emulsion can lend a tint to the finished negative, even if the developer comes out unstained. Greg.

[Digitaltruth]

First, let me say that I am not an expert in pre-washing, so hopefully someone else will enter this thread to provide more information.

Prewashing is normally done to soften the emulsion so that when the developer is poured into the tank it is more readily and evenly absorbed. As such, it is a technique for avoiding uneven development, especially when using a short development time.

Although this was commonly recommended with older film stock, modern emulsions are much less prone to uneven development and presoaking is not usually recommended unless your development time is extremely short. However, there are certain more specialist developers which do recommend prewashing due to their particular characteristics.

I would therefore recommend that you follow the manufacturers recommendation for the developer you are using.

The dye should not affect the final image in any way and can be ignored. If you prefer to clear the dye it is a matter of your own preference. You can get rid of it (or most of it) by increasing the time in the fixer, using a second fresh fixing bath, or using an extended time in a washing aid.

[Greg Winterflood]

Thanks for joining in Jon. And thanks for sending me the 4 rolls of Efke 127. My interest is piqued because Efke/Adox seem to be saying that they have rescued some 'vintage' equipment and are using it to produce film with the same properties as film from the 1950s.

If that is the case, I am wondering if efke film should be treated as if it were a 'vintage' emulsion, rather than a modern emulsion.

Either way, I am going to give my first roll of efke a prewash in order to see the blue dye come out. Others on the internet have said that they have kept a sample of the brilliantly dyed blue water, just for the fun of it.

Fun. That has to be a good reason to prewash! Even if it only applies to efke film.

[Digitaltruth]

Efke film is made by Fotokemika in Croatia who own the brand. Their coating facility has been in operation for many years and I'm not aware of any major changes in equipment. The Efke films do have an older-style emulsion, but the film base is more modern so you should not need to treat the products as if they are "vintage." Having said that, I doubt there would be any harm in pre-soaking these films, and if you have seen other posts on the Internet where people have done this, then I'm sure it will be fine. Enjoy the blue dye!

[Ornello]

Does anyone prewash before developing?

I'm completely new to developing B&W and along with everything I can find on the web I have been reading Ansel Adams' The Negative. He mentions prewashing, but beyond that I have only come across it with recommendations for Rollei R3 film. Adams explains how it softens the emultion for development. Are there any reasons why it isn't prevalent?

In other words, what are the reasons for not prewashing?

Thanks for sharing your knowledge
Jay

First of all, all pre-washing or prewetting does is to help get more even development. I do it. Be sure to drain thoroughly before adding developer to the tank.

Secondly, the book you mentioned is not good for 35mm work. Adams' way of doing things is either obsolete or was wrong to begin with for miniature format (35mm). I have a manuscript in preparation that represents modern appoaches to film development and enlarging. I can let you read what I have finished if you send me a PM.

[nielsf5]

I use pre-soak for all my film processing. Aside from the benefit of even developer take-up and air-bell prevention, there is another more subtle effect which I have read about (somewhere). There is a slight reduction in contrast compared with a non pre-soaked neg. My own ridiculously unscientific experiments and experience seems to bear this out. Maybe the pre-soak acts in the same way as a water bath development, initially at least. Just my 10 bobs worth. Regards, Niels R.

[Ornello]

I use pre-soak for all my film processing. Aside from the benefit of even developer take-up and air-bell prevention, there is another more subtle effect which I have read about (somewhere). There is a slight reduction in contrast compared with a non pre-soaked neg. My own ridiculously unscientific experiments and experience seems to bear this out. Maybe the pre-soak acts in the same way as a water bath development, initially at least. Just my 10 bobs worth. Regards, Niels R.

Perhaps this stems from slight dilution of the developer at the beginning of the development. Anyway, I approve of the practice.

[Greg Winterflood]

I posted a photo of what I poured out of my Paterson tank last night after prewashing some efke of its anti-halation dye. The photo is here

http://www.flickr.com/photos/94097267@N00/440731294/

This morning the colour had lost its brilliance.

[brooklynkid]

After retirement I attended some photography classes at the local community college. The professors recommended prewashing to "open up" the emulsion. Hope this helps.

[Wirehead]

From what I've read, most modern films contain various surfactants that ensure that the developer is absorbed quickly into dry film. They also help with high-speed coating. By this token, a prewash is not necessary and will cause the developer to be absorbed slower than dry film, hence leading to lowered contrast because the developer take-up time is slowed.

The zone folks tend to think that an extended prewet can be used to adjust the tonal curve.

I've also heard that some modern films, to get fast enough coating rate, will end up with too much surfactant content and will be especially prone to air bubbles as a result when you develop them in hand tanks.

Also, the Efke IR820c datasheet specifically tells you to pre-wash.

On the other hand, unlike most things that people have been doing long enough to forget why, there's very little evidence that a pre-wash is harmful in an otherwise well-controlled process...

[WYOMING TOM]

Since I am using fairly short developing times at present cutting just below 5 mins at 68º a presoak helps to reduce a myriad of problems all of various forms of uneveneness because it adds time . Also it tempers your entire system of development so you have more consistent images. While I have yet to do 1-60 RODINAL for compensated low contrast development it makes sense to go SLOW rather than FAST. I spend hours indeed DAYS going to a locale shotting my brains out and not doing test rolls, in end note bracket.

[Ornello]

Since I am using fairly short developing times at present cutting just below 5 mins at 68º a presoak helps to reduce a myriad of problems all of various forms of uneveneness because it adds time . Also it tempers your entire system of development so you have more consistent images. While I have yet to do 1-60 RODINAL for compensated low contrast development it makes sense to go SLOW rather than FAST. I spend hours indeed DAYS going to a locale shotting my brains out and not doing test rolls, in end note bracket.

I strongly recommend times longer than 5 minutes. I suggest at least 8 minutes, and I prefer 10-12 minutes. To do this, dilute your developer more or use boric acid to slow it down.

[CJBas]

Pre-soaking will make the formation of bubbles almost impossible when you pour the developer in. Yes, it does also help even developoment (especially for short develolping times), and it may reduce contrast (though I can't verify that).

But if the film is already wet when the developer is poured in, then bubles will not be able to form on the film's surface because of the sruface tension created by the water already there. And if you've ever had a negative ruined by a buble that formed for the first 20-30 seconds of development onthe film's surface then you'll be glad to pre-soak you film.

[Ornello]

Pre-soaking will make the formation of bubbles almost impossible when you pour the developer in. Yes, it does also help even developoment (especially for short develolping times), and it may reduce contrast (though I can't verify that).

But if the film is already wet when the developer is poured in, then bubles will not be able to form on the film's surface because of the sruface tension created by the water already there. And if you've ever had a negative ruined by a buble that formed for the first 20-30 seconds of development onthe film's surface then you'll be glad to pre-soak you film.

I agree strongly. I got fed up with bubble effects. I always pre-wet the film.