Ra4 processing consistency advice

[Bumba]

Thanks for the advice. I'm going to increase the temperature and keep the time the same until I match the density of the fresh developer. What are the signs of overdeveloping? What sort of fog will I get?

Pentaxuser: I use a similar method of reusing chemicals as I have a litre bottle of developer and I use what I need and return it to the bottle. I don't replenish but might have to start. Your method sounds good. Also my drum seems to take ages to drain properly. 20 secs might be a bit overkill but I like to empty it as much as possible. It's 1:05 in developer plus the 20 secs drain so 1:25 in total before stop bath.

 

[Photo Engineer]

Have you ever thought to run this at Room Temp?????

It works very well.

PE

 

[Bumba]

Have you ever thought to run this at Room Temp?????

It works very well.

PE

Never thought about it to be honest. Could you give me an idea of what temp and times I should be aiming for with room temp please? I'm in the UK so it never gets too warm unfortunately haha

 

[Photo Engineer]

Try 20C for 2 minutes for the developer, 2 minutes for the blix and about 30 minutes for the wash.

PE

 

[koraks]

I find that both time and temperature are not very critical at room temperature. I do consistently time development just because it's easy, but I have noted little difference between, say, 17C and 22C. Sure, there is some difference, but the difference of eg variations in developer pH are much more problematic.

 

[Bumba]

Thanks, I'll give it a shot and see how it goes. I've got nothing to lose at this rate haha

 

[Bumba]

In the end I mixed up some new chemicals because even at 35c for 2 mins, I couldn't get the density as good as with fresh chemicals at 28c for 2 mins. What I learned is that when reusing chemicals the colour will shift cooler over time unless this is compensated for with increasing development time or temp. I still had good blacks with old chemicals but the prints were much cooler than fresh chemicals. I hope this helps someone out in the future as it's something I overlooked.

Anyway, I was looking in my Tetenal instruction book and it had this comment on replenishment. "After the 2nd throughput, replace 1/3 of the original tank contents with fresh solution. The bleach fix times must be extended by 15 seconds, but all other times remain the same".

Two questions about this. What do they mean by throughput? And why extend only the blix time?

 

[koraks]

By throughput, they likely refer to the specified capacity of the developer, but I'm not sure.
In a replenished system, development times don't have to be increased because rhe developer is rejuvenated - that's what the replenishment is for, after all. It prevents the problems you've been running into, which is also why it's specifically stated in the manual.

 

[Bumba]

Okay, thanks for that. Novice question but do you replenish blix aswell or is it only developer that is replenished?

 

[koraks]

I think you could technically replenish blix, but I personally prefer to discard it after some time and mix fresh.

 

[Bumba]

Okay thanks Koraks. I'll get there eventually (I hope)

 

[Photo Engineer]

With every use, the paper uses up some chemicals and releases others during development and bixing. The ones in the developer are critical to color and density, but the ones in blixing are critical in removing Silver.

As you reuse, color balance and density will change as a function of developer use. The blix is far less sensitive and can just be used for a longer time, up to a point. Using a stop after the developer (1 - 2% acetic acid or white vinegar) will help.

If you insist on reuse, then you may have problems. I often run a tray process at 20C with 1 - 2 L of developer and I can get by with quite a few 8x10s, but with a tray I don't use a prewet. It is diluting the developer and that has another effect on the process.

PE

 

[Bumba]

Thanks Photo Engineer. I'm starting to understand the properties and roles of the chemicals a bit more now. I'll hopefully figure out a work pattern that is repeatable.

 

[halfaman]

I print RA-4 in a Jobo and develepor can be reused with consistent results but taking care of the paper dimensions. 500 ml can be reused during a whole morning session with 8x10'' paper in a 2830, but should be increased to 800-1000 ml if you print 11x16''. I use a 3% acetic acid stop bath follow by two 30 seconds washes between developer and blix.

You won't need prewet with the above quantities (there is a loss of developer by paper absorbtion without prewet).

 

[Bumba]

Thanks Halfaman, that's very insightful and will have to give that process a try.

I feel that I have a list of problems that I need to get resolved as I've unearthed a new one to do with my enlarger bulb. When I make a test strip I expose 1/5 of the paper which is shielded by a mask. The paper is then slid across, filtration is changed in increments then the next exposure is made on the same strip etc. until there is 5 exposures.

Anyway, as each exposure is made, the bulb has been turned on for cumulative amounts of time. This means that by the 5th exposure the bulb has been on for a long time. I've found that the density decreases, the longer the bulb has been on for. The first exposure has good density then by the 2nd and 3rd it's noticeably lower.

I usually turn the enlarger on for 30 secs before hand. Each exposure is 11 secs and about 5 secs Inbetweeners each exposure to allow me to adjust filtration.

Has anyone experienced this before? Should I allow the bulb to warm up for longer or is the bulb on its last legs? I wish I wasn't so stubborn with the darkroom, as I would have given up a long time ago and life would be more relaxing haha. Thanks

 

[Photo Engineer]

This is actually not good darkroom practice. There are other ways to do this such as using a filter matrix, and these could be purchased years ago. It is more normal to use a set of CC filters on the paper if you must do this, with the enlarger set at the center point you wish to work form.

PE

 

[koraks]

Has anyone experienced this before?

No, and I can't explain it. I'd be tempted to get a new bulb and see if it does any better. I get no such inconsistencies with my light sources (all old bulbs btw).
What kind of power supply is there between the bulb and the timer/wall socket? Does it work properly? Maybe it's not the bulb.

 

[Bumba]

Sorry for the late reply but I've just returned from my holidays. I have a filter matrix but I don't really use it so I'll see if I can get any good results with that. Failing that, are there any other suggestions on how to get the filtration correct?
It's plugged into the UK mains and it's a Durst enlarger with a Durst transformer and timer. All seems well but I don't know anything about electronics really.

 

[pentaxuser]

Bumba if the Durst bulb comes on then all I can think of is checking if the light intensity fluctuates during exposure. You can usually see this if you switch on and expose for say 10 secs. This can be a sign that the bulb is on its way out or it may be that the ceramic holder that plugs into the prongs on the bulb needs cleaning. Try and scrap the inside of the holes in the ceramic holder with a thin jeweller's file or a thickish sewing needle to clean it of carbon that forms inside the holes. Ideally when you change bulbs change the ceramic holder as well.

This may affect the colour balance but it is a long shot. I fear that other causes are more likely but if you have done everything that has been suggested then there is not much left that might be the cause

Unless the bulb is relatively new then I'd certainly consider a bulb change. If the bulb is old this is likely to alter the temperature at which it burns and this can affect the colour balance

pentaxuser

 

[Bumba]

Thanks Pentaxuser. I'll check for any corrosion etc on the bulb or holder. The bulb isn't affecting the colour balance, it's affecting the density. The longer the bulb is on then the lower the density but I think at a certain point it levels out. The difference only seems about 1 or 2 secs at f11 density

 

[koraks]

I'd have that power supply checked (well, I'd do it myself if it were mine, but if you're not all too handy with electronics, maybe you'd prefer to have someone look at it).

 

[Bumba]

Hi, it's me again. Just have a quick question (if such thing exists).

Are the symptoms of underdevelopment and underexposure the same? I was getting images that looked a bit washed out but on the bottom of these I exposed a little strip from double the amount of time. I got solid black on the double exposed area but the blacks in my image were blueish. I increased my exposure time by 1/2 second and the blacks look fuller.

Anyway, I was wondering if I was under developing and compensating by exposing a bit longer, or if the development was fine and I was just underexposing originally. Is this bad practice or does it not matter as long as the end result is suitable?

Thanks and I don't think it was a quick question in the end

 

[Photo Engineer]

The symptoms are different. Simply put, you cannot get a black black with under development.

PE

 

[Bumba]

Thanks Photo Engineer. I'm on the right track then. Slowly but surely

 

[Bumba]

I'm back again. I've changed my process since last time and now I'm trying a replenishment system with the drums so we shall see how it goes. I just had a few questions about the blix though.
1) Is it possible to over blix a print?
2) If I'm replenishing blix then do I need to aerate it?
3) Will blix be stable enough to use replenished?
4) What are signs of blix not working?
5) I read that blix needs developer to work best. Does this mean a stop bath is a bad idea?

Thanks for any help and sorry for all the questions.