Rodinal question, again.

New to Rodinal and I see 1:25, 1:50, 1:100 and more. Ok I know the more diluted you do the longer it takes for the development time. Is the longer developments only advantage is more control of the process. Why would it be more advantageous to use a longer rather a short development time. Ok the next basic question, Could I use regular tap water for my Rodinal since I do use Distilled with my Fix. Not that I am trying to be cheap on the first stage but semi cold water out of the tap is easier to work with.

You would be better to use distilled water with the developer and tap water with the fix.

The only reason for high-dilution, long developing times is for "stand" development, which is
a style of development with almost no agitation. Some people feel this gives extra sharpness
to the negative due to exaggerated adjacency effects.

Using dilute developers allows the developer exhaust in the highlights and work longer in midtones and shadows. This gives more detail in the shadows that more concentrated developer may not be able to produce.

Using tap water for most fixers is OK unless the directions provided with the fixer say otherwise.

TR

There is a lot of... lore... about Rodinal.

If you are a normal, attentive photographer, your agitation my vary from 5 to 10 seconds,
your temperature might vary from -2 to +2 of your target,
and the time you start the timer, to the time your development might stop
will vary from +/- 15 seconds to +/- 30 seconds.

Like it or not, we are fallible.

A 16 minute development time is far less likely to show the normal error that would an 8 minute time.

Control is EVERYTHING. Repeatabilty is your best friend.

Dilution has NO direct effect on the image, but agitation (which is an indirect effect of dilution) DOES have an effect.
It is a very poerful control with Rodinal. (search threads about minimal agitation)

Tap water is a fine stop bath. Since Rodinal needs a very high pH to develop, a pH neutral stop bath (water) is an instant stop. Using acid would make no difference. Use water as close to the developer temp as possible.

Higher dilutions like 1+100 are good for more than stand development. I've used that dilution for decades with normal 5-in-30-second, or 10-in-60-second agitation, or Jobo constant rotary agitation development, all for normal contrast. In the neighborhood of 12 minutes with common small tank inversion agitation at 1+100 is good for films like Panatomic-X, Pan-F+, or Efke/Adox 25 ISO films. As df cardwell says, you have easier control over a longer process, and greater dilutions can give you that, regardless of your agitation routine.

Try the tap water and see if it works. It varies too much for anyone else to advise you on whether it will work well in your location without trying it.

Lee

Yes, it's distilled water if you go by the book. I've been using tap water with rodinal for year and it has had no ill effect.

High dilution is also good for cheap skates like me who get MAX $ out of every ml!

For more info:http://unblinkingeye.com/Articles/Rodinal/rodinal.html

Thanks for the info and links. The funny thing is DF Cardwell is correct in the time keeping. When it says this is the time, when does it actually start. I know I try to follow but things do happen. I deceided to use the 1:50 dilution because I try but things do happen. Tap water is going to be used when needed. Jim there is not such thing as cheap skates, just a little more frugal.

Rodinal must be the single most responsive developer I've ever tried. Changing your agitation really does change the results. It's nice to play with, and is an extremely useful developer for scenes with ridiculous contrast range, like shooting up into the dome of a cathedral.
Remember that when you dilute your developer a lot, you still need to maintain a minimum level of at least 2.5-3ml of concentrate per roll (a ridiculously low number). I use Rodinal at 1+200 with Plus-X, but I always use 500ml or so per roll, to ensure enough chemistry.

Have fun! Rodinal is really fun stuff.