Just how important is the Stop Bath process in developing?

[thomas_t]

I have been developing my own BW for about 2 years now. Instead of a stop bath step

between developing and fixing, I usually rinse thoroughly with 3 water rinses lasting about

45 seconds before moving on to fixing. My negatives look good so far, but am I taking a

risk in terms of longevity by skipping the stop bath and using just a water rinse? In short,

am I going to regret this in a decade when I look back at the negatives. Any thoughts and

wisdom would be greatly appreciated, cheers :-)

[lowell_huff1]

Stop Bath is not necessary at all if you are using a rapid fixer (acid). It is "some what" necessary if you are fixing with HYPO. The purpose of stop bath is to change the pH of the developer in the emulsion, thus stopping development and to protect the fix bath from developer carry-over. Acid fixers are buffered against the alkalinity of the developer, HYPO is not.

[henry_a]

Good info about stop baths was posted earlier on 11-10-04 by Rowland Mowery --scroll down the page to read it.

[richard_cochran]

<cite>Am I taking a risk in terms of longevity by skipping the stop bath</cite>

<p>

As long as your negatives are fixed and washed properly,

longevity won't be hurt by whether or not you use a stop bath.

<p>

But a stop bath can extend the life of acid fixer, by neutralizing

any alkaline developer before it has a chance to carry over into

the fix. If acid fixer is contaiminated with developer, it

may not be as effective, and this could indirectly lead

to a longevity problem.

<p>

Multiple water rinses probably get rid of most of the developer

before it has a chance to get into the fixer, though.

[scott_eaton]

What Richard said.

 

I worked for a local metro with a staff of damn fine B/W photographers and two custom labs that still provide exellent, hand B/W processing services; none use stop bath with B/W films.

[james_ogara1]

Particularly with shorter (say 5 mins) developing times, is there a benefit to stop bath in that it ends development at a point certain, thus fostering consistency?

[john_shriver]

<p>Geez, you can't scroll 30 threads down the screen, for a <a href="http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00A4N2">thread</a> on the subject by an expert? That thread convinced me to use stop bath consistently.</p>

 

<p>As the screen said, please look before asking.</p>

[tim obrien]

That thread convinced me to do what I am doing... develop, water bath, TF-4 fix, minimal rinse (10 min, one water change per minute).

 

I have no problems with fog, scum, bad fixer, streaking, or any of those other possible issues.

 

Do what works for you. You don't need acid stop, use if you need to fix a problem.

 

 

tim in san jose

[patrick_gainer]

"Particularly with shorter (say 5 mins) developing times, is there a benefit to stop bath in that it ends development at a point certain, thus fostering consistency?"

 

In any case, if you are pouring the developer out and the stop bath in, there is likelihood of a difference in developing time. You could use a separate tank for stop, turn lights off just before end of development, remove reel from developer and dunk in stop bath. OR, you could add fixer concentrate directly to developer at end of developing time. Most of the concentrates are thick enough that 1 oz. for each 7 oz. developer is sufficient. If your tank is full of developer, pout 1/8 of it out and add an equal amount of concentrate. This pouring time is much less than that of emptying the whole tank and filling it with stop bath. A vigorous initial agitation will assure even fixing. It is no worse than the unevenness you might incur by pouring out developer and pouring in stop bath.

[lex_jenkins]

Since the topic was more than adequately covered in these previous threads I'm locking this thread from further replies and referring folks to those earlier threads:

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=009ZDV

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00A4N2