Kodak RA/RT Usage Advice (Replenishment)

koraks

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What seems a bit odd is that it looks like the 3 minute @ 20C strip is lighter than the 2 minute strip at 20C. Did you label them correctly? If so, then there's a change you've got another source of variation there.

BTW just checked my chemistry and it develops a fully exposed (lights on) strip in about the same time as yours to full black; I timed 26 seconds. This is at approx 17C.
 

mshchem

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You can leave the print in the drum for longer than 45 seconds. When I'm processing with my Kodak machine, I make sure it goes at least 45 s at 100 F, I've let it go a minute and a half with no discernable difference. The easiest way is to pour as much hot water as you can in the drum to preheat. Use more chemistry, you have 20 L of replenisher!
 

mshchem

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Re: trays. The RT/LU is made for roller transport / low use.

Here's a link to tech pub J-39 this is Kodak's recommend use instructions.
 
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Bumba

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Yeah Koraks, I found that strange but it is labelled correctly. It's the least dense one.

Thanks for the advice Mshchem. I've unfortunately read that Kodak manual top to bottom multiple times haha. I'm using a jobo drum but without the machine itself. Do you have any tips to consistency at higher temp. I tried it when I first started and every test strip had different density. Not sure if the temp was drifting or I wasn't developing long enough.
 

koraks

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Bumba said:
Yeah Koraks, I found that strange but it is labelled correctly. It's the least dense one.
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Then you have at least one more problem to deal with. A longer development time will never result in less density if all other parameters stayed the same.
This is one of those situations where I wish I could look over your shoulder to see what you're doing exactly as you may be running into something you're not aware of.
 
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Bumba

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Yeah you're totally right. Now you mention it, consistency has always been a problem for me when processing so as you said there is most likely something else happening.

I'll have to think on it and get back to you.
 
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Bumba

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Just a quick update. Thought it might be an exposure problem so did a test strip with increasing exposure but you can't see any definition between each increment and the most exposed section still looks pale so that didn't work. Maybe it's an oxidation thing with the drums.
 
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Bumba

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The nightmare of RA4 is in full swing and biting me on the behind.

I've tried out some various times and temps with 2 pre washes to get the drum up to temperature but I always experience a 4-5°c drift during the process. Can I expect any sort of repeatability with that kind of drift?

I'm not using a tempering bath for the drum either so maybe I need to look into that. Really struggling with the room temp too. Save me! Haha
 

koraks

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Temperature should not be extremely critical as long as development time is sufficient. You're currently focusing on temperature stability but as we've discussed before I have the feeling there may be other things amiss in your work flow that have a larger effect.
Have you tried trays yet with let's say 500ml of developer in a tray? That will at least eliminate any issues associated with drums as you're using them including the small developer volumes used for each sheet/strip.
Have you tested developer pH? Have you verified correct mixing ratios of the developer? Is your developer properly started/seasoned?
 
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Bumba

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I haven't currently got a way to use trays but might have to look into it. Also I unfortunately don't have a pH meter but I did mix the full 5 litres all at once and used up all my concentrates. The Dev concentrates I had weren't sealed with foil but my blix concentrates were. I'm not sure if this is normal or not. Also my developer isn't seasoned and I also didn't use a starter. What effect would there be from not using a starter?

Thanks for the help
 
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Bumba

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Just to report back. I made a test strip with exposures from 10 seconds - 20 seconds. O processed this at room temp for 2 mins.

At first looks it seems like I'm getting good density now but only in the exposures that are quite long. If I process at 35°c my exposure is 11 seconds but at room temp something around the 16 second mark looks about the same.

Is this bad practice or just the way it is? Seems to me like a bad practice of overexposing and pulling the development but the results don't look bad. I'll have to look at it properly in daylight.
 

koraks

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Exposure times should not be much different for different developer temperatures. 11 VS 16 seconds is way too much. Color balance may be a bit different.
 
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Bumba

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I'm back and I've been working away in the darkroom. After processing a strip at 35°c and a new exposure strip (in a more precise way) at room temperature I've found the difference between the two to be 2 seconds. At 35°c I use 11 seconds but at room temp it's 13 seconds. I also bumped up the development time to a full 2 minutes of agitation instead of stopping early to drain. It all looks good to me do far. Is it normal to bump up exposure a little if I'm processing at room temperature? They look pretty close apart from a little cyan shift.
 

koraks

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I haven't tested for this specifically so I don't know for sure. But a small difference doesn't surprise me, although ideally it wouldn't exist obviously.
 
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Bumba

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Yeah it's all starting to look pretty good now I've made some adjustments. Just a few more trivial questions before I get on with it:

1) I'm not using a pre wash. Will the accumulation of the anti halation dye from the paper into the developer have any negative effects on the developer? Could it stain my paper or does it have no effect?

2) I store my chemicals in my laundry room overnight and the temperature is about 16°c but by the end of the day they are about 20°c. Will this change in temperature cause inconsistencies in colour balance or does out make no difference at such low temperatures

3) Before my blix I'm using a stop bath then wash. I assume that over time the wash carryover will dilute the blix. I'm already replenishing at 15ml per 8x10. Will this be sufficient or should I bump up !y replenishment rate?

Sorry for all the stupid questions but I just want to learn haha. Also thank you for all the help everyone, especially you Koraks.
 

koraks

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I never noticed a problem with this despite never using a prewash and having used the same batch of replenished developer for over a year (hence it's pretty much saturated with muck).

Again, I never noted problems with this. I wouldn't let the stuff cool down too much in order to prevent anything from precipitating out, which will likely not be much of an issue anyway with a working stock. Anything above 10C should probably be just fine.

3) Before my blix I'm using a stop bath then wash. I assume that over time the wash carryover will dilute the blix. I'm already replenishing at 15ml per 8x10. Will this be sufficient or should I bump up !y replenishment rate?
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I replenish my blix way less and don't use a wash between stop and blix, and my blix still blixes like any blix that has ever blixed before. Or, better put: as long as you replenish according to the manufacturer's spec, I wouldn't worry about it. Blix is tremendously overdimensioned, or put differently, its usage instructions are insanely conservative.
 
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Bumba

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Thank you Koraks. You're a legend in my eyes! Very, very last thing. What are the signs of blix not working or is there a test to do similar to how you test developer?
 

koraks

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Bumba said:
What are the signs of blix not working
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Reduced saturation and somewhat increased contrast in the image, a slight color shift most likely (towards blueish hues), and as the print is exposed to strong light coloration of the white borders and highlights in the image.
You can test Blix by putting a piece of exposed, developed and fixed b&w paper into it and see if it nearly clears in a few minutes. Or develop a piece of color paper in b&w developer with the lights on and then chuck it into the blix; it should clear entirely in a few seconds.
 
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Bumba

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Thanks Koraks. That's makes a fair bit of sense, especially about the boarders. I'll be back soon with either a finished print or many more questions about how it all went wrong. Wish me luck
 
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Bumba

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I'm back because it's never smooth sailing for me haha. Just a quick question this time though. Do you guys warm up your enlargers before printing? The longer my bulb is on then over time the density decreases but i think it stabilises at a point.
 
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Bumba

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Okay thanks again Koraks. I think my bulb is a bit duff in that case. I'll see if I can work with it for now
 

koraks

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This sounds a bit odd really. I can't imagine a failure mode in a bulb where it will vary its spectrum over an extended period of time (perhaps a second or so just before it burns out altogether). I could imagine stability issues with supply fluctuations, but as far as I know this is extremely rare. Can you share some details on the light source, its power supply and are there any known oddities with your mains supply at home?
 
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Bumba

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Just looked at my bulb and theres a bit of corrosion on the pins. Maybe that's causing problems and it doesn't work when not positioned correctly.

Don't know much about electrics btw so not sure about the mains.
 
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