Beginner Darkroom Printing Question

[LabRat]

White light exposure on MG produces a long scale #2, but filtered #2 is a shorter scale. .


Steve K

[Pere Casals]

White light exposure on MG produces a long scale #2, but filtered #2 is a shorter scale. .
Steve K

IMHO the white light and #2 produce the same "scale".

White light alone allows shorter exposures, if not stopping the lens then the exposure time have a certain impact...

But if we manage to have the same exposure then the #2 and the white light (tungsten) produces the same.

Anyway in both cases we obtain from the same naked barite to the same coat of metallic silver, the DMax of the paper.

[Bill Burk]

Pere,

The difficulty is minor, but if you make a test strip without a filter, and you need to make another test strip with a filter, you'll find a different base exposure.

Mostly the inconvenience is that I have trouble comparing two "slightly" different test strips. I just went with graded paper to solve this problem for myself.

But I remember feeling "dumb" that I made one print without a filter, and now have to figure out what the best guess time would be for a print with a filter.

If I had made a test strip with a grade 2 filter, at least I'd have narrowed down a best guess time.

[LabRat]

[QUOTE=Pere Casals;1461954]IMHO the white light and #2 produce the same "scale".

No, with MG, you get a different shadow density with and without filter, but much more so with MGRC than MGFB... It was common in pro lab printing to use a #2 filter if the shadows were overall too dark...

Filtered or unfiltered will have a different exposure, due to the filter cutting light and the spectrum changing...

Steve K

[Pere Casals]

No, with MG, you get a different shadow density with and without filter, but much more so with MGRC than MGFB... It was common in pro lab printing to use a #2 filter if the shadows were overall too dark...

Steve, the #2 filter is designed to allow to pass the "same share" of green than of blue with a regular tungsten spectrum, but the filter may have a quite different effect depending on the spectrum of the source light (speaking about cold cathode in Pro labs ?), if the light source is not tungsten it may happen that the filter matching the white light is not exactly the #2, with cold cathode the grades from the filters are not evenly spaced, then there are shifts.

See here Chapter "Cold cathode enlarger heads" in the Ilford VC document, page 3: https://www.ilfordphoto.com/wp/wp-co...Multigrade.pdf

Note: the "same share" is related to the effect in the 3 emulsions of the VC paper, with tungsten...

See this scales (from the ilford doc):



..so we see that when inserting the #2 filter in an Aristo cold cathode we obtain grade #3 !!!!! So it's possible that by removing the filter you got something closer to #2 with white light...

Well, if cold cathode is a difuser then that grade #3 (from filter #2 in the Aristo) would also be softer that a condenser with grade #3, because the condenser vs difuser effect.

Pere,

The difficulty is minor, but if you make a test strip without a filter, and you need to make another test strip with a filter, you'll find a different base exposure.

Bill, I found that calibration solves that, at least for a learner like me. http://www.darkroomautomation.com/support/



Once one gets used to deal with tables/plots and spot measuring light on the easel we can nail what we want, or at least we can predict the final density in any spot of the print. At the beginning it's a bit stressing, but once one gets used to paper calibrations I guess it's like riding a bicycle. Still I'm learning that, but I find it's a right way control the print as we want.

Of course a very skilled printer may obtain what he wants with some strips, not needing tables, but that's not my level and calibrations helps me a lot to not waste entire paper boxes.

A (retired) very good darkroom color printer (wedding) explained me that (by measuring things) he always nailed the amazing skin tone of the girl's cheek and the right exposure in the first color print, and told me that this was the way to not throw materials and to speedup production. I guessed he was right after wasting two paper boxes for a print and not being able to get a sound result.


My view is that with a complex print we have to be able to easily nail the densities we want en each key spot, because later we have to face local contrast control and there is a relevant workload with split grade burning/dodging.

Also learning to make easily printable negatives is key... I guess !

[Steve Sherman]

This is a fairly advanced technique I'll share, understanding Multi-Contrast papers respond to both Green & Blue filtration, therefore using filtration that combines one with the other progressively diminishes the flexibility that MC papers offer. The only filtration I use is 0 & 5, in varying combinations to create the desired beginning contrast using 2 separate exposures. Secondary "split printing" is again done with only 0 or 5, anything in between simply extends the time to affect the desired outcome, and "contaminates" mid-tone contrast. This approach should be the underlying foundation and the first rule of how to print when using MC papers.

[Pere Casals]

Steve, my view is that with split grade we end in a regular grade. At the end with split grade we throw an amount of blue and an amount of green, what's a regular contrast filter also does.

Of course red is irrelevant and it's always let to pass to see better while we dodge/burn...

The advantage I see in split grade is that we can dodge/burn while exposing with the #00 or while exposing with the #5, so we get local contrast control, but I found no difference in the mids from the equivalent filter grade, this is what sensitometric curves suggest, please correct me if I'm wrong.

[Steve Sherman]

Steve, my view is that with split grade we end in a regular grade. At the end with split grade we throw an amount of blue and an amount of green, what's a regular contrast filter also does.

Of course red is irrelevant and it's always let to pass to see better while we dodge/burn...

The advantage I see in split grade is that we can dodge/burn while exposing with the #00 or while exposing with the #5, so we get local contrast control, but I found no difference in the mids from the equivalent filter grade, this is what sensitometric curves suggest, please correct me if I'm wrong.

That is correct, the general contrast of the print, in my world is dictated by the most difficult area of the print to manipulate, a combination of 0 & 5 filtration will yeild that contrast. That could be grade 3.25, so in the way I combine the two exposures can yield a grade inbetween grade 3 & 3.5. I am more talking about buring or dodging with grades inbetween 0 or 5 simply degrades mid tone contrast. What many do not seem to grasp is the beginning and ending tonailites are fairly easy to arrive at, most people when looking at a print react with the mid tone relationships and that is why I put so much emphasis on those relationships in the print. The beginning and ending tonalities should be determined when making the negative so the focus can be on affecting mid tone contrast in the final print. At least that is the way I go about designing a negative and making a print.

[Pere Casals]

I am more talking about buring or dodging with grades inbetween 0 or 5 simply degrades mid tone contrast.

Well, this depends on how we do it... if after an general exposure with suitable grade we burn higlights with the #5 then midtones won't be changed, only highlights will build additional density...

But I fully agree that is not making a good negative then we have a lot of troubles in the darkroom.

Let me ask how you would print this negative: https://www.flickr.com/photos/125592...posted-public/

I've been struggling with it a lot and still I'm not satisfied...

[Steve Sherman]

Pere. Are those negative density readings ?? If so you are
pushing the boundaries of Silver Gelatin. 1.7 & 1.9 I would
suggest flashing. I’ll look at the image on a big computer screen tonight as I am just on a cell
phone now