ADOX(efke) push processing

[Davor K]

Hi,

does someone know developing times for push processing (35 mm):

Efke (ADOX CHS) 100 ; Efke (ADOX CHS) 50 ; Efke (ADOX CHS) 25 ?

At home I have ILFORD MICROPHEN, ID - 11, XTol , ROLLEI RHS .


Davor

 

[Ian Grant]

Remember those are the Tungsten light speeds, daylight is a stop faster.

Ian

 

[Tofek]

You mean Adox CHS100 has to be shot at 50ASA in daylight, CHS25 at 12ASA etc ?

 

[Davor K]

Thanks Ian. I know that, but I am interesting to expose and develop Efkes to higher ISO
than it's nominal. It is possible with Acufine (efke 100 to 250). I need informations for
some other developers maybe ILFORD MICROPHEN, ID11, Xtol, Rollei RHS .
Davor

 

[Ian Grant]

Look at the old Adox EFKE Data sheet Kb/R 14 is now called Adox CHS 25, the 17 -50 and the 21 -100. The old names were the DIN speed in Tungsten light, the new ones the ASA/BS part of the ISO.



I think Microphen would be the closest to KR E24, you might use the EFKE recommended starting times, and those speeds you want are there in the datasheet. Many Eastern block PQ developers were similar to Ilfords published formulae.

Ian

 

[nicholai]

You mean Adox CHS100 has to be shot at 50ASA in daylight, CHS25 at 12ASA etc ?

I assume it's the other way around; CHS100 is to be exposed at EI 200 in daylight.

 

[Ian Grant]

I assume it's the other way around; CHS100 is to be exposed at EI 200 in daylight.

That's right, in fact for a number of years a UK chain of photo stores sold EFKE films under their own brand name and they were sold as 50, 100 & 200 ISO films. So CHS 100 was Jessops 200.

I began using KB14 later renamed EFKE (Adox) 25 back in the 70's and in more recent years have used the Pl25 sheet film version, I expose & process at 50 EI, which is what I rate Tmax 100 at, and I process both for the same development times - sometimes in the same tank.

Ian

 

[Davor K]

Thanks for (old) data sheet Ian. I shooted KB25, KB50 in daylight at their nominal speed, developed in TETENAL NEOFIN BLUE and results were very good. But, developing in PERCEPTOL is different , must be expose at lower sensitivity. Obtained speed is depending on developer. That is my experience.
Davor

 

[ath]

And Maco PO100 is supposed to have been a (maybe selected?) batch of Efke 50.

 

[Gerald C Koch]

Under exposing by one stop should be within the latitude of most films and would be developed normally. Anything more than one stop will result in a loss of shadow detail. Extending development to compensate will result in higher contrast abd grain. Photographers do not usually push slow or medium speed films under normal conditions but just shoot a faster film. This produces better results than pushing.

 

[Ian Grant]

Gerald, EFKE films are quite different because the spectral sensitivity differs from most films, they aren't fully panchromatic. This leads to a greater than usual difference in Daylight & Tungsten speed, so there's not under exposure at twice the box speed in daylight, it's what EFKE state (correctly) is the daylight sped.

Ian

 

[Gerald C Koch]

Gerald, EFKE films are quite different because the spectral sensitivity differs from most films, they aren't fully panchromatic. This leads to a greater than usual difference in Daylight & Tungsten speed, so there's not under exposure at twice the box speed in daylight, it's what EFKE state (correctly) is the daylight sped.

Ian

Granted so you would develop normally whether D or T as there is really no pushing involved. But that doesn't seem to be what the OP is asking.