gtmuk
Hi everyone,
I’m using Ortho 25 (35 mm 35 mm film) to photograph microscales on film. (Imagine photographing a transparent plastic ruler against a white background from a good two metres away.)
So far, I’ve been developing the 25 in Ilfosol S, but it all looks too soft to me. I don’t need any grey tones in there; I want the film to be black and the scale lines white.
What do people usually use for this film if they want high contrast?
Side note: The grain mustn’t be too coarse, because the line width on the film is only about 1/50 mm and must remain sharply defined.
On the other hand, I don’t mind the speed, nor the development time. (The scales will hold steady for as long as needed, and good things take time...)
While I’m on a philosophical tangent: This also ties in well with Mirko’s interview in Die Welt: All this rigmarole still isn’t feasible digitally to this day. The end product is the negative (no prints or enlargements) and although you can certainly capture the image just as sharply with a 20-MP camera, there is no printer that can conjure up 250 or 300 lines per mm onto a transparent film. :) Unfortunately, it’s just a hobby, so there’s hardly any money to be made from it. :(
Best regards,
Thomas.
KlausWehner
Just give it a go with a paper developer.
The grain won’t (probably) be a problem with this film.
The development time is (probably) not critical, as you’re developing the film (just like the paper).
You’ll need to watch out for an increase in base fog (shorten the development time if necessary).
Good luck – and do let us know how it goes.
Warm regards from Paderborn
Klaus
gtmuk
Just give it a go with a paper developer.
The grain won’t (probably) be a problem with this film.
The development time isn’t (probably) critical, as you’re developing the film (just like you would the paper).
You’ll need to watch out for an increase in base fog (shorten the development time if necessary).
Good luck – and let us know how it goes.
Warm regards from Paderborn
Klaus
Thanks, Klaus.
You’re right, it’s worth a try, even if it costs a roll or two of film.
But I’ll also try one from Wolfgang’s list at the same time – Rodinal, for example, which I remember from the old days.
Regards, Thomas.
gtmuk
Here are a few times:
http://www.digitaltruth.com/devchart.php?Film=ADOX+Ort+25&Developer=&mdc=Search
Best regards,
Wolfgang
Hello Wolfgang,
Thank you very much, that helps me a great deal. Someone else also suggested D-19 to me – it isn’t on the list, but by cross-referencing you can work out a time that’s more or less correct. As Klaus already said, the exact time isn’t that critical for me, or rather, it can be optimised by sacrificing one or two rolls of film.
Greetings from Wales to the homeland,
Thomas.
gtmuk
Hi everyone,
As suggested by Klaus, I’d like to share the results of my development experiments today.
First, I developed the Ortho 25 in Kodak D-76 (stock solution). The exposure was at ISO 25, and at 6 minutes and 20 degrees, the film delivers results that are quite accurate.
Then I used Kodak D-19, also a stock solution, which is a document developer. It works a bit harder and a bit faster. During another exposure at ISO 25, you get almost equivalent results at just 5 minutes and 20 degrees, but with slightly more contrast.
(I took a series of shots with +/- 2–3 exposure stops, some in half-stops, to always capture the correct exposure.)
However, in the meantime, another film was recommended to me: the Rollei ATO2.1. It’s nominally 25 ISO as well, but in my opinion it falls far short of that. Because I need the higher contrast, I’ve mainly processed the Rollei with D-19.
The result was as follows, at 6 minutes and 20 degrees:
With BM at ISO 25, one should actually have used 1/8s + f/8. In reality, however, an exposure time of 1s at f/8 was needed to achieve roughly the same density as, for example, the Ortho. The film therefore has a sensitivity closer to ISO 3 or perhaps 5.
As this surprised me, I carried out two further tests, which merely confirmed the findings:
- Development of Rollei ATO2.1 in D-76, 6 minutes at 20 degrees: same result. Approximately 8 times the exposure time (i.e. 3 stops) was required compared to the theoretical value for ISO 25.
- Development in D-19, but for 9 minutes instead of 6. Result: The extra 3 minutes yield approximately half a stop of increased sensitivity, and naturally larger grain.
As I have neither an enlarger nor a negative scanner (I only need the negative), I can’t really upload anything of decent quality. So I tried using a microscope and a digital camera. The images were all taken at approx. 100x enlargement and show the centre of the negative. The out-of-focusness is therefore also due to the optics of the microscope and the camera adapter.
The subject is a black line 1 or 0.5 mm wide on a white background, captured in 35mm format from a distance of about 2 metres using a 50mm lens. I realise this is hardly representative for most people, but I wanted to show something at least, and it was simply the best comparison subject for me.
All in all, one can say that the Ortho25 produces decent results with standard developers and standard processing times, which was also evident from my Ilfosol experiments some time ago.
As hoped, the Rollei ATO2.1 works a fair bit harder (without the grain becoming too terrible), though it requires an enormous amount of light – about 3 stops more.
And finally, the D-19 can be recommended as a hard-working (and fast) developer. However, it is probably not widely or easily available.
Best regards,
Thomas.
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