Rodinal 1:100 & KB25 is pushing 3 stops!!

S

Steve Karr

Film tank shaker
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Hi everyone,
So I was reading about 1:100 stand and thought I'd try it.

My friend was over and I shot a quick portrait of him and the negs came back nearly bullet proof. Really, like 3-4 stop over - something... exposed or processed.

I had my first roll of KB25 in the Leica and I hand metered at 25asa and compensated for a 3 stop Red filter. I know what you may be thinking I went the wrong way... that's what I thought too, but I tested it with 3 runs and it comes back the same each time.

KB25
Rodinal 1:100 ( 1, 2 or 3 reels in tank tests)
68* to start 70 at end of 1 hour stand
1 min inversions to start, don't touch for an hour.
Minolta V, Minolta Spot & M6ttl meter were all in agreement

So why is this 3 stops pushed speed wise? I like the higher contrast, but the speed thing is still troubling me.

Test without Filter


Red Filter


Frame from M6 TTL Meter (thru 3 stop Red filter) set at 50asa






Thanks~
Steve

Ps... Jason from the bullet proof first roll
 
Wrong film, Efke 25 in Rodinal1+100 is perfect for 10~11 minutes
so doing stand is going to be an over-overkill
By developing (even with no agitation) for long time you are overdeveloping the heck out of it. I do not know if the contrast is high or low... if it is low you maybe on to something.

Maybe at 1+200?
 
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There are many, many references to Rodinal 1:100 Stand 1 hr. with KB25 on the net, including our very own P. Lynn.

I don't understand why my technique is pushing this film. I kinda like it Hi contrast & tight grain in a 200 speed film but I don't like no knowing why this is happening.

Any Ideas??

Hmmm ....
 
You might want to have a look at the curves for this film compared to others like FP4+ or Plus-X. I haven't checked but if the red/blue wavelength sensitivity is different to 'standard' films then you may find a clue. Read the extract below and also consider the colour temperature of the lighting under which you took the shots. Tungsten light is going to have more red in it than fluoro or daylight.
And then there's the dilution and stand development method you chose. A lot of potential for things to go skewed, I think.

Quote:
"Sensitivity of Efke 25 is 14 DIN (20 ASA, ISO 20/14° GOST 18), but by developing in coinciding developers effecting Efkes sensitivity utilization may be even twice increased to 100 ISO. This film is orthopanchromatic, making it less sensitive to the red end of the spectrum than standard pan film." Unquote:

Quote:
"Films can be pushed one stop for increased speed and optimum differentiation of highlights
Do NOT over-expose Efke Emulsions! This film is not recommended for pull processing".
Unquote:

So the instructions are saying 1) don't overexpose, 2) you can increase the rating by about 1-2 stops, 3) it's less sensitive to red than normal films and 4) don't pull process the film.
 
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.......... and you can not use an orthopan film with a red filter. You are filtering out all sensitivity of the film and you will get all strange things.
 
Leigh Youdale said:
Quote:
"Films can be pushed one stop for increased speed and optimum differentiation of highlights
Do NOT over-expose Efke Emulsions! This film is not recommended for pull processing".
Click to expand...

Hi Leigh,

I don't know who says that, but it's totally false. Efke25 works very well -just like any other B&W film- with generous exposure and real short development under direct sun...

I meter it incident at ISO3 with yellow filter. The same way, I meter Tri-X at ISO50... It all depends on the development...

Overexpose Efke films! They're recommended for pull processing!
And on soft light underexpose them and increase contrast with longer development times!

Cheers,

Juan
 
I wonder why they say that, as I have never had problems with it... Maybe they say it to make people think the film is "fast enough"? Strange... (I've used it with Rodinal only, by the way...)

Cheers,

Juan
 
It has to do that Efke films are single layer films with a high Silver content. When developing Efke the best choice is a surface high acutance developer: Rodinal 1+50 - 1+100, Tetenal Neofin Blue, Beutler A+B, FX-1 etc.

When going to pull this film heavily the emulsion can not make proportional the shadows and highlights. On the other hand it's no problem to push Efke 25 one F stop. While Efke 25 and 50 are both Orthopan films and the Efke 100 is panchromatic you can think why that 50 version is still being made...........

BTW the 35mm base changed 2 years ago from Tri-Acetate to Blue PET (Polyester base) but the emulsion itself did not changed. So their website is not 100% up to date :)
 
Efke 25 in Beutler A+B 1+1+10 7:00 minutes. M7 + Summarit 2,5/75mm

A very easy to make developer: Metol, Sodiumsulfite and (washing) Soda (Sodiumcarbonate). For further improvement of acutance the alternative is FX-1, add a very small amount of Potassiumiodide. No problem to enlarge this (35mm) negative to a 40x50cm photo print.

3531595018_f19fb577aa.jpg
 
Dude...
your "bulletproof" portrait example shows that barely any light hit the film!
I don't know how you've scanned it but if it's so black means the neg must have been quite transparent...no details in his face...

The high contrast in your tests is there indeed, but even there some parts re pitch black.
 
Pherdinand's totally right. And some strips have gray base that should be black. From your own material you can see what you got... Underexposure.

Efke25 can't be pushed three stops with any developer. Beyond its real speed, it can be pushed 1 stop. Pushing it 2 stops means losing lots of tonal range. 3 stops is getting dark crap: "an image" for scanning and photoshop...

Cheers,

Juan
 
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