Once again: colour positive development by eye?

canned · 2004-10-03T19:48:54+00:00

hallo liebes forum, gibt es jemanden unter euch, der die farbwerte bei der positiventwicklung PER AUGE (d.h. ohne hilfsmittel, ausser natürlich den teststre...

canned

Hello everyone, Is there anyone among you who can determine the colour values during positive development BY EYE (i.e. without any aids, apart from the test strips for fine-tuning, of course)? Photography literature states that, with plenty of experience, the colour values can be determined to within a few degrees by projecting the negative onto the ground glass. Is there anyone who can do this or who practises it in this way? How should I interpret the projected negative to ensure that the resulting colour values are APPROXIMATELY correct? Is this solely a matter of correctly interpreting complementary colours (as simple as that may sound in theory...)? Does it help to use the brightest (whitest) spot in the positive as a starting point to eliminate colour casts? And the brightest and darkest spots to determine the exposure time? Regards & thanks for any tips, canned Resources for colour positive development (see this forum): http://www.fotoimpex.de/forum/index.php?act=ST&f=2&t=370 http://www.fotoimpex.de/forum/index.php?act=ST&f=2&t=369

Gast

>> Photography literature claims that, with plenty of experience, the colour values can be determined by the negative projected onto the base plate. To put it politely, that’s a rather dubious claim – or rather, complete nonsense. Where did you read that? Best regards, Ferdinand

canned

A quick beginner’s question: why not? <_< Are the colour values not visible because you always see that reddish cast from the negative film (as the raw material) as well – or is the whole point of colour filtering to filter out that colour cast (red/yellow)? Why is colour filtering necessary at all in colour positive development? Where does the deviation come from that I need to correct with filters? What should ‘the perfect’ negative look like when projected onto the base plate? Are there any specific characteristics – or does the final result depend on the paper used (which a colour analyser would need to be calibrated for, wouldn’t it)? Regards, canned

Gast

canned, the masking of the colour negative film prevents any meaningful recognition of colours. It takes quite a bit of imagination to visualise the positive image (in colour!) at all. Any (potential) colour cast is masked by the excess of ‘orange’. Colour filtering is necessary because - human vision, just like differences in brightness, can compensate to a certain extent for differences in the colour temperature of light. Example: Take a photograph with daylight film (slide) under artificial light (incandescent bulbs). The slide appears SIGNIFICANTLY redder than the artificial light does to us. - film materials cannot be produced with 100% consistency. Compensation for colour masking is already ‘built into’ the paper. Best regards Ferdinand

Gast

Hello canned, I know a lab technician at a fairly large studio near us who works visually. As far as I can remember – it’s been a while since I took that course with her – she first made a test strip to determine the exposure time and then used test strips under standard lighting to filter out the colour cast. However, she only ever filtered with y and m, leaving c constant. Making the test strip was also easier in that lab, as they had a large continuous-feed system there. You slid the paper into a slot in the darkroom and it came out again in the daylight workroom. I still remember how fascinated I was when she made a contact print from a negative film. She looked at it, sorted the negatives by exposure and, using masking, conjured up the contact print in one go. But as I said, the good lady earns her living doing this. Regards, Sven.