View Full Version : BTZS, matching film development to paper ES

19-Oct-2011, 09:19
I have been trying to tighten the reigns on my BTZS testing. In the past, I tested my film development and used a standard paper exposure scale (ES) of about 1.05 I think. Then I used VC paper exposed with a dichroic light source and everything came out fine.

Now I moved on from 4x5 to 8x10 and I am re-working things. My VC cold light produces lower contrast than the dichroic head I use for 4x5 so I think I need to adjust my film development to be a better match for the VC paper.

So my question is: is it better to err on the side of overdeveloped (higher contrast) negatives printed on lower contrast VC paper, or to err on underdeveloped (less contrast) negatives printed on higher contrast paper? If it makes much difference either way, what is the reason?

Based on my testing, I need to adjust development of the negatives from matching a paper ES of 1.05 to a new ES of ~1.2 on the cold light source. That would result in TMY2 processed in a Jobo 3005 in Xtol 1:1 at 68 degrees for ~8 minutes for an SBR of 7, FYI.

Oren Grad
19-Oct-2011, 09:58
So my question is: is it better to err on the side of overdeveloped (higher contrast) negatives printed on lower contrast VC paper, or to err on underdeveloped (less contrast) negatives printed on higher contrast paper? If it makes much difference either way, what is the reason?

I prefer to err on the side of underdevelopment. The characteristic curves of VC papers tend to get noticeably lumpy below about grade 1, so I try to stay away from that range. With conservative development I find that almost all of my negatives print to my taste somewhere between grades 1-3.

19-Oct-2011, 10:53
Hi jeroldharter - Since your cold light paper test gave you an ES of 1.2 (grade 1) then put that number into your film test file in the Plotter Program and use that. If your test does not produce enough contrast to get a SBR of 5 with XTOL 1+1 at 68 degrees, then you might want to do another test using XTOL at 1+0.

Are you enlarging your 8x10 negatives or doing contact prints? What paper?

I would go with the results you get from your film & paper testing and there should be no need to over or under - develop your negatives.

Also if you are processing your negatives in a Jobo - there would be no need to retest your 8x10 film, but if you are using BTZS tubes or trays you should retest, since your agitation would be different for 4x5 & 8x10.

Fred Newman

19-Oct-2011, 11:11
Thanks Fred.

I am using Kentmere FinePrint VC FB paper in Dektol 1:3.

I am enlarging the 8x10 negatives (though I will make occasional contact prints).

I can get to an SBR of 5 (barely) with Xtol 1:1.

Another way to ask my question is which ES from the range of VC possibilities should I use? Given that my printing setup is relatively low contrast, is it better to generate really contrasty negatives and then use lower grades of paper? Or is it better to use one of the lower ES (which keeps the development times reasonable also) and then print at a higher contrast setting? For my variable, an ES of ~1.2 is right in the middle of the pack.

Good to know about the testing re 4x5 and 8x10 in a Jobo. Yes, my 4x5 test was in a Jobo and then I was lazy and used that data for 8x10 as well. Good to know that I was smart and efficient rather than lazy after all.

Andrew O'Neill
19-Oct-2011, 11:33
I develop my film to a DR of 1.35 for my cold light heads.

19-Oct-2011, 13:07
Why err at all?

Your paper is VC, which means you can filter the light and set the papers ES where you want it--not accept the ES you get from the paper unfiltered. Grade two is from 1.0 to 1.1. There is a chart in the BTZS book explaining how grades are not objective, but Davis chooses this ranges as grade two and the midpoint between grade 1 and 5. Choose 1.05 as the midpoint and find out what filtration gives you that ES on your paper. Then develop all your film to match. If you've been developing your film to match paper at an ES of 1.05, you shouldn't have to change film development at all.

19-Oct-2011, 13:41
Hi jeroldharter

You can email your plotter file for the Kentmere VC paper & I can over over it with you on the phone if that will make it easier. Also details of enlarger light source, VC filters used, and more. Once I see the paper & film test I will be able to further help you.

Fred Newman

19-Oct-2011, 15:44
My negative library contains a fair share of underexposed, overdeveloped film.

I got a spot meter and it has taken my film exposure to a new level.

I am now leaning toward shortening my developing times, based on my equipment, method and materials (BTZS tubes, hand rotated, TXP320, D76 stock).

I prefer to increase contrast with VC filters than to try to print through blown highlights and dodge lower values.

19-Oct-2011, 16:38

Thanks for the help. I sent you an email with the plotter files for my film and paper.


1.35? Good to know. I was worried that I might end up overbaking at 1.2.


I understand your point. I have been using a default ES of 1.05 which works OK but sometimes I have to crank up the contrast to get some bite in the print. That is why I did the paper test and found out that the paper (with my light source) has a max of Grade 3 per the BTZS designations. So it makes sense that I increase development. I am trying to gauge how far I should go with it realizing that the paper gives me some room for error.


BTZS works very well. The spot meter plus BTZS controls makes printing much easier and more predictable. I am satisfied with my results but I am trying to tweak my methods for the 8x10 system I am using. I have a nice Sekonic spot meter and rarely use it. I went over to the incident system and really like it with BTZS. So consider giving it a try alongside your spot metering and see which works best for you.

Thanks everyone for the feedback and advice.

19-Oct-2011, 18:32
Agreed on the incident reading. I take both incident and spot readings when possible, which for me is most of the time when taking portraits and nature/still life shots. Taking both readings helps me understand the lighting better.

Andrew O'Neill
20-Oct-2011, 11:42
Why err at all?

Because ideally you want your negative to "fit" on your choice of paper's grade 2 even if it's a VC paper.

20-Oct-2011, 16:17
Andrew, that is my point. If you are fitting your negative to print on your choice of paper's grade two, even if it's a VC paper, then that is not erring--it is using the system as designed.

The second issue then is what constitutes grade two. As Davis points out in his book, there is no standard definition. He suggests an ES of 1.0 to 1.1 (midpoint 1.05) as grade two, regardless of the paper being used. With VC paper, you can adjust the contrast, so thereby designating that range as grade two. Determining your paper's ES, or setting it with filters to a specific ES, and exposing and developing the negative to match it is not erring.

20-Oct-2011, 16:26
Perhaps "err" was not the best choice of words. What I meant was that I could choose among multiple ES's of the VC paper's ES range for film matching; so is there an advantage for choosing a lower ES or a higher ES?

Thanks to Fred Newman at the View Camera Store for speaking with me on the phone. I appreciate the help.

20-Oct-2011, 20:42
If you VC head works you should be able to use a single development time for almost any representational image.

23-Oct-2011, 06:43
I am going to retest my film this week (perhaps using a new light meter) and match to a paper ES of 1.2 to account for the inherently low contrast of my 8x10 light source. I will retain the ES of 1.05 with 4x5 TMY2 for 5x5 printed on a different (Beseler 45s) light source.

Thanks also to Fred Newman for taking time to talk to me about these things.

23-Oct-2011, 23:28
Hi Jerold

It was great talking to you. Any help you need just call me.

Fred Newman