Adox CHS 25 in HC 110, thin negs.

[MortenBS]

Hello!

I've ben out shooting some long exposures with my Mamiya RZ.

The first roll of Adox CHS 25 came out really thin and underexposed.
I developed it in HC-110 dilution B for 7 minutes agitation first 30s and then 5s every 30s as recommended on the bottle.

It seems as the contrast is high, but the negs are too thin and underexposed.

The massive devchart suggests dilution H 7 mins for iso 50, but my logic tells me you need more time in the developer with a thinner diluted developer. Am I right?

Any tips on how to make the next roll come out better with this developer? With more shadow detail.

I think I might have underexposed the film a bit, as result of a miscalculation of filter factors and reciprocity failure in the field.

I also have the Moersch eco developer at hand, which I've enjoyed very much with other films. but no developing time for the adox film.

 

[Thomas Bertilsson]

First you get exposure right.

Then you worry about developer.

Shoot one more roll of this film, but expose it properly. Bracket if you must.
Without getting exposure right in the first place, it makes zero sense to analyze your developer.
An analogy would be that when you build a house you start with the foundation, (which in this case is your exposure). Then you work your way up.

 

[MortenBS]

Yes of course that makes sense.

The thing is, that I've used this film with good results before, but not with this developer. It's exposed same way as I use to.
I have one more roll already exposed and after seeing the first come come out really thin, I would like to push the next one 1 stop.
Any advise for doing this would be appreciated.

 

[Richard S. (rich815)]

How long is long exposure?

 

[MortenBS]

Exposures ranged from 1-3 minutes. In sunlight with a polarizer, yellow filter and ND 3.0 filter.
I've compensated for reciprocity failure with 2/3rds of a stop.

 

[vedmak]

why do you need ND filter if your resulting exposure ends up being 3 min?

 

[MortenBS]

The ND filter cuts 10 stops of light. That's what makes me able to get a 3 minute exposure in broad daylight. I like to do landscapes with very long exposures to get the clouds moving across the sky.

 

[Richard S. (rich815)]

I think you have more reciprocity failure than you might expect going on. Consider using Fuji Acros instead would be my first thought.

 

[MortenBS]

I think I'm right on the reciprocity failure. I read some test from the photo.net forum with the same results as on the adox website.
I developed another roll in HC-110 dilution H for 15 minutes as suggested by a flickr member. This one came out better with lower contrast and more dense negatives with more details.
Thanks for the replies.

 

[Thomas Bertilsson]

I think I'm right on the reciprocity failure. I read some test from the photo.net forum with the same results as on the adox website.
I developed another roll in HC-110 dilution H for 15 minutes as suggested by a flickr member. This one came out better with lower contrast and more dense negatives with more details.
Thanks for the replies.

Lower contrast when you develop longer? The opposite is supposed to happen... Very puzzling.

But as long as you're happy, all is good.

 

[MortenBS]

Yes, well the lower contrast because of the thinner dilution and less agitation.
agitated 5 seconds every minute as opposed to 5seconds every 30 seconds.

 

[polyglot]

You're way underestimating the reciprocity failure if you're applying only 2/3 stop compensation for a minute+ exposure. Even for a 30s exposure, you probably want 2+ stops.

 

[MortenBS]

polygot:

yes I know with most other films, you would need to compenseate a lot more, but a quick google search will tell you otherwise about this film.
And it is my experience that this is correct:

http://www.adox.de/english/ADOX Films/Art/ADOX_Films/page1/page1.html

I came to the conclusion, that I was not precise enough in calculating the exposure when compensating for yellow/orang/red filter and the polarizer.
I increased exposure with 1 stop for the yellow filter, 1,5 for orange, and 2,5 stops for the red filter. All the images shot with the yellow or orange filters came out underexposed, whereas the onces taken with red filter were almost perfectly exposed. So I've learned something there.

Could this have something to do with the film being less sensitive to red colors?

And the roll developed with dilution H came out much better.

 

[Thomas Bertilsson]

I believe this film is repackaged Efke 25, which has reduced red sensitivity.
This means that compared to normal panchromatic film, you will either have to compensate a lot more with the red filter, or refrain from using it at all.

 

[Alexis M]

If this film is like ADOX CMS 20, fixing time needs to be lowered. Like 1-2 min in rapid fixer.

 

[Thomas Bertilsson]

If this film is like ADOX CMS 20, fixing time needs to be lowered. Like 1-2 min in rapid fixer.

It isn't.

 

[Ed Bray]

I realise this is an old thread, but looking at your figures your exposure would have been very underexposed even with a 3 minute exposure.

Taking the sunny 16 rule as a start would give you 1/25th sec @ f16, add a stop for the yellow filter 1/12 @ f16, 2.5 stops for the Polariser 1/2 sec @ f16 (1/12-1/6, 1/6-1/3, 1/3-1/2) then 10 stops for the ND 3.0 1/2sec-1sec (1), 1sec-2sec (2) 2sec-4sec (3) 4sec-8sec (4) 8sec-15sec (5) 15sec-30sec (6) 30sec-1min (7) 1min-2min (8) 2min-4min (9) 4min-8min (10) then add on the Reciprocity for 8 minutes of 1 stop gives a final exposure of 16 minutes.

If you opened up the aperture from f16 -f8 you could just about have got away with a 4 minute exposure.