getting a personal EI without an enlarger or densimeter?

[Bill Burk]

I think your practical flare model is the way to go.. I've been using the original fixed flare model.

 

[Xmas]

I think your practical flare model is the way to go.. I've been using the original fixed flare model.

I normally use a single coated lens for the higher flare level.
But the nicest signature is from uncoated lenses.
These choices are subjective not your process modelling.
If the sky is 100% battle ship grey I'll use a MC lens.

On a bright sunny day the single coated lens compress the scene brightness range adaptively.

 

[rbultman]

I'll add these two which are good for starters, for those wanting some simple basics:

http://motion.kodak.com/motion/uplo...en_motion_education_sensitometry_workbook.pdf

http://motion.kodak.com/motion/uplo...etters_filmEss_06_Characteristics_of_Film.pdf

Excellent, thanks.

Regards,
Rob

 

[rbultman]

I follow a most useful chart in the darkroom when I prepare to develop a roll of film.

This is my Time/Contrast chart.

Bill, Is that development time in minutes in the X axis?

Regards,
Rob

 

[Stephen Benskin]

This is my Time/Contrast chart.

While I claim I am able to develop film to any contrast I want, the scatter points reveal the harsh reality.

It's a good thing that I do not offer my services to others. "Let me scratch your film" would be my motto.

It does appear that my laboratory is not under control. But I know how far out of control I am and I can do something about it.

There are two points I would like to explain about this graph.

1. Underdevelopment is the most common error in my darkroom. So I would not want to deliberately aim low, because I might hit lower still.

2. Despite missing my aimed contrast very often and significantly, all the negatives I developed are easily printable. There is that much tolerance in the black and white negative process.

There is an excellent section on The Development Constants on page 444 of The Theory of the Photographic Process. It's about interpretation of the time/gradient curve. A subject not often covered anywhere. Here's a synopsis I put together some time back.

View attachment Development Constants 9.2011.doc

The subject is important enough to have it's own thread but I'm afraid the topic might be too esoteric.

 

[markbarendt]

Thanks for that explanation.

Regards,
Rob

You bet.

I can't help but think that this is close to being dead on judging from the number of people that end up shooting at this EI. Or, they are just a bunch of lemmings...

Regards,
Rob

Do you/they have a specific problem that was/would be solved by that EI change? (For example; are your/their shots regularly and truly under-exposed, is important shadow detail is truly missing from the negative, when shot at box speed?)

Do you/they have a specific problem that was/would be solved by that reduction in negative contrast on most all shots? (For example; do you/they normally need to use a softer paper grade when printing?)

 

[removed account4]

John, it permeates nearly every thread having to do with films, developers, processes and printing. People like to talk about the "tonalities" of different films and developers, the "real" speed of film x, how reduced agitation does this or that etc. This is all sensitometry. But dare to present some sensitometric data or theory which might show what is happening vs what someone thinks is happening, and all of a sudden they're not interested in technicalities anymore.

Anyhow, I've written way too much in this thread so I'll leave it to the rest of the participants at this point.

michael:

the way i see it is sometimes people know how to speak the language and sometimes they don't
and maybe i am just giving the benefit of the doubt, when i say this but maybe when they are asked
to present sensitometric data they can't because the data they have isn't written or graphed out &c but
through their own personal observations / experience with the product they are talking about.
i once had a thread here where i asked for just that - personal experiences ... and not experience through scientific testing
and some people got extremely upset because i wasn't interested in their data.
for some folks, personal experiences, good enough &c isn't good enough ...

sure speed, tonality &c is all senitometry ... and technical oriented people know, understand and can converse about sensitometry; it is not a language *I* ( and maybe others? ) have learned ...
while i have clicked a shutter button for 45 years, and have developed and printed images for i guess about 35 of them and worked on commission
for maybe 30 of them ... i never found it necessary to invested in the tools to gather the data, what to do with that knowledge, or even how to read a film graph.
i used my eyes to understand what i am looking at, nothing else ... and my exposures and prints have been good enough that people have paid me for them ...
if i was ever blabbing in a thread about tonality and speed &c and asked to present data &c i wouldn't really know
what to say or how to say it ... maybe the people / person / persons you refer to have the same gaping hole in their photography experience as i do ...
or maybe not ?

YMMV

 

[Bill Burk]

Bill, Is that development time in minutes in the X axis?

Regards,
Rob

Yes, exactly.

 

[RobC]

I have a friend who is getting into B&W film. He understands that a proper negative is very important and as such wants to test to get his own Exposure indexes, or film speeds, to shoot at. problem is at this time he has no enlarger (he might pick one up if he gets really into it) and no densimeter. he asked me if there is a way to get an EI of his own for his developer without those 2 key items. I had no idea so I thought I would ask you guys for any advice you might have.

thanks

john

See following which is geared towards zone system without the sensitometry.

(there was a url link here which no longer exists)

He can contact print the negs so he doesn't need an enlarger !!!

 

[rbultman]

You bet.



Do you/they have a specific problem that was/would be solved by that EI change? (For example; are your/their shots regularly and truly under-exposed, is important shadow detail is truly missing from the negative, when shot at box speed?)

Do you/they have a specific problem that was/would be solved by that reduction in negative contrast on most all shots? (For example; do you/they normally need to use a softer paper grade when printing?)

If have had very few shots that were either under or overexposed when using an in-camera meter. (All of my film cameras have simple, center-weighted or spot meters, none have matrix metering). One that I had difficulty printing* is in my gallery. (There are two. It is the daylight scene.) I can't measure the density range of the negative as I have neither the equipment more the knowledge, although I am trying to gain the latter. When I printed on VC paper using single-grade filtering, it required significant burning in of the sky in order for it not to be completely blank. Burning in was difficult due to the sharp edges of the buildings and tanks. When I printed using split-grade filtering, it made it much easier to print but I still don't like it. There is not enough detail in the shadows and the clouds are largely featureless. I'm not sure I could have done much from a developing standpoint other than reduce it in order to reduce the highlight density. I did not attempt to burn or dodge the print made using split-grade filtering.

I will need to check my notes, but I think the printing time for split grade was something like 90 seconds for the shadows and 30 for the highlights. This seemed excessively long to me, which could indicate overexposure, overdevelopment, or both. I really don't have a good feel for typical print times for 35mm negatives. This was for an 8x10 print on a Beseler 23C II enlarger with color head. I used the M and Y filters in the head for filtration. I don't remember which lens I used but it was what I have seen as normal for 35mm film, maybe a 50mm? Aperture was probably f8. Again, all in my notes.

* I have made about 4 prints in my life. I took an intro to darkroom course where I produced a couple of prints. The two in my gallery are what I have printed at home. The setup and tear-down time for my temporary darkroom is about 1 hour each. I am hoping to be able to reduce this overhead down to 30 minutes or less in the coming months once I complete some home renovations. I won't be able to have a dedicated darkroom for several years. I can't seem to find local darkroom space for rent which would allow me to get some experience without the huge time overhead of setup and teardown or my own darkroom.

Regards,
Rob

 

[pdeeh]

Negatives shot at 1/2 or 1/4 speed will have more shadow detail on the negative than those shot at box, but that doesn't mean that extra detail will print, or that you even want it to print. To print that extra detail, and still place the face where you planned it to be, you have to change other things like film contrast or paper grade, or start burning and dodging.

Sometimes I wonder if many people get sucked into chasing "shadow detail" as an end in itself, without ever stopping to think why they might want a lot of shadow detail, or whether having it is in the service of the photograph they are trying to make.

I say this because I visited this very madness upon myself for a little while, after I'd started trying to learn more about how film works and how to control what ends up on the film. It increasingly dawned on me, that for the sort of photographs I like to make, the lusted-after shadow detail was pretty much irrelevant ... it really was such a relief!

(As an aside, and entirely coincidentally, I was looking very closely at a print by Bill Brandt yesterday - a real print, in a frame, on a wall! - and I noticed that great slabs of shadow were undifferentiated maximum black. Great photograph too, and I mean "great" as it used to be used, not merely as a term of mild approbation).

 

[Photo Engineer]

You might all consider this.

Modern films and papers are designed, when printed to an 8x10, and at grade 2, to require an exposure time of between 10" and 12" at f5.6 to f8. This is with the proper enlarger, diffuser or condenser, and lens. So, you do not use a 4x5 enlarger and condenser with a lens designed for 4x5, nor do you use the cones incorrectly. If the setup is right, the exposure should be approximately what I have given above.

This is nearly such a correct value that we used to design sheet papers (professional) for this exposure range.

So, if you need 1' or thereabouts or some such strange exposure, your enlarger, lamp, diffuser, condenser, lens or cone is not correct. In this modern age, such "facts" are not known I guess. Of course, the negative could be overexposed or overdeveloped.

PE

 

[pdeeh]

That is incredibly reassuring PE!

Because in the past few months my exposures have started to converge on 10-15 seconds at about that print size & apertures, having for the past two years been all over the place (mostly, much shorter). I'm hoping this means my negatives are getting more consistent ...

 

[markbarendt]

There is not enough detail in the shadows and the clouds are largely featureless. I'm not sure I could have done much from a developing standpoint other than reduce it in order to reduce the highlight density. I did not attempt to burn or dodge the print made using split-grade filtering.

First, try a test printing a few strips using a bit less enlarger exposure to see if the shadow detail you want is on the negative, ignore the rest of the print. If the details are printable then the camera exposure you used was probably fine.

Next use an even softer paper grade or split grade. As you soften contrast though the tonality changes, you may reach a point where the photo just looks "flat" rather than "nice and snappy". When you reach that point you need to add back some snap then start Burning & Dodging to get the rest of the detail.

Having to use softer paper is a good indicator that the film could have been developed less for that particular scene, who knows what the next scene brings though.

If it was my shot and I was comfortably within the VC range of my paper's contrast adjustment range (which is the norm for me), then I see little point in adjusting the film development.

 

[RobC]

You might all consider this.

Modern films and papers are designed, when printed to an 8x10, and at grade 2, to require an exposure time of between 10" and 12" at f5.6 to f8. This is with the proper enlarger, diffuser or condenser, and lens. So, you do not use a 4x5 enlarger and condenser with a lens designed for 4x5, nor do you use the cones incorrectly. If the setup is right, the exposure should be approximately what I have given above.

This is nearly such a correct value that we used to design sheet papers (professional) for this exposure range.

So, if you need 1' or thereabouts or some such strange exposure, your enlarger, lamp, diffuser, condenser, lens or cone is not correct. In this modern age, such "facts" are not known I guess. Of course, the negative could be overexposed or overdeveloped.

PE

I presume this takes into consideration paper reciprocity so that if you are doing the test I suggest at following

(there was a url link here which no longer exists)

and print at size you want to make big prints at, then you are factoring in your print size, print aperture and print time and paper reciprocity to your film EI and dev.

Thats very cool and doesn't require any sensitometry and hence time wasting and graph making and table data entry and list making and all the other associated gubbins that sensitometry brings to making a simple task a PITA.

The film and paper manufacturers have thought it all through and made our lives easy by taking the donkey work out of it for us.

 

[removed account4]

You might all consider this.

Modern films and papers are designed, when printed to an 8x10, and at grade 2, to require an exposure time of between 10" and 12" at f5.6 to f8. This is with the proper enlarger, diffuser or condenser, and lens. So, you do not use a 4x5 enlarger and condenser with a lens designed for 4x5, nor do you use the cones incorrectly. If the setup is right, the exposure should be approximately what I have given above.

This is nearly such a correct value that we used to design sheet papers (professional) for this exposure range.

So, if you need 1' or thereabouts or some such strange exposure, your enlarger, lamp, diffuser, condenser, lens or cone is not correct. In this modern age, such "facts" are not known I guess. Of course, the negative could be overexposed or overdeveloped.

PE

giving away all the industry secret standards !
thanks for the nuggets ( as always )

 

[rbultman]

You might all consider this.

Modern films and papers are designed, when printed to an 8x10, and at grade 2, to require an exposure time of between 10" and 12" at f5.6 to f8. This is with the proper enlarger, diffuser or condenser, and lens. So, you do not use a 4x5 enlarger and condenser with a lens designed for 4x5, nor do you use the cones incorrectly. If the setup is right, the exposure should be approximately what I have given above.

This is nearly such a correct value that we used to design sheet papers (professional) for this exposure range.

So, if you need 1' or thereabouts or some such strange exposure, your enlarger, lamp, diffuser, condenser, lens or cone is not correct. In this modern age, such "facts" are not known I guess. Of course, the negative could be overexposed or overdeveloped.

PE

Is this for graded or VC papers? Looking at the Ilford contrast control tech document for VC papers, no filtration is grade 2. How does using filtration for split grade printing affect print times? I assume it would lengthen them.

Just to make sure I understand, 10" is 10 seconds, right?

Regards,
Rob

Sent from my Nexus 5 using Tapatalk

 

[Stephen Benskin]

i don't see it like that at all ..
maybe i am not as invested as you
or don't care ...

John, just an FYI. Some of that is going on right now.

 

[removed account4]

John, just an FYI. Some of that is going on right now.

i think it is always going on, and i am in the middle of it ... kind of like not seeing the forest through the trees

 

[Stephen Benskin]

i think it is always going on, and i am in the middle of it ... kind of like not seeing the forest through the trees

Fair enough.

 

[Photo Engineer]

I presume this takes into consideration paper reciprocity so that if you are doing the test I suggest at following

(there was a url link here which no longer exists)

and print at size you want to make big prints at, then you are factoring in your print size, print aperture and print time and paper reciprocity to your film EI and dev.

Thats very cool and doesn't require any sensitometry and hence time wasting and graph making and table data entry and list making and all the other associated gubbins that sensitometry brings to making a simple task a PITA.

The film and paper manufacturers have thought it all through and made our lives easy by taking the donkey work out of it for us.

You should remember that I don't use the zone system and so your reference is bouncing off my shields! ;(

An 8x10, with enlarger set properly, and printing from a 35 mm negative should require just about the same exposure as from a 4x5 considering the fact that the enlarger light is more concentrated for the 35mm due to the change in diffuser or condenser. Reciprocity failure is then centered about this value of about 10" to 12" (seconds). It diverges, depending on paper on either side, and the rate of change depends on paper.

It also works for VC at grade 2, but remember that all changes in grade involve changes in either emulsion or filter or both and these impact on exposure times. For VC, see the filter factors for your individual paper.

Papers intended for laser printers and other types of short exposures such as conventional photofinisher optical printers operate at an average of 1/2" or much less and so the reciprocity failure and other properties are adjusted appropriately. We often exposed paper emulsions at both 1/2" and 10" and did reciprocity failure tests to see which product range an emulsion would be best suited for.

PE

 

[RobC]

interesting, I was taught and have aimed for since, a print exposure time of around 20 seconds becasue thats about enough todo some dodging and burning. The shorter the print time is the more difficult it is to feather in your burns and dodges. But nice to know paper will probably perform best at the aperture and times you give. Well it would if Kodak were still making it. What about Ilford, do they use the same times and apertures?

 

[Photo Engineer]

Rob, if it is a professional negative, we assumed a minimum of dodging and burning, but with a simple click of the aperture you could go from 12" to 24" with no trouble at all.

Also, dodging and burning introduce their own reciprocity failure. You must be aware of that.

PE

 

[Stephen Benskin]

Two Time/Gradient Curves. Same film different developers.



From the PMK curve, we can conclude it would be very hard to over process. The low development velocity means that the film is very tolerant of processing errors. One minute more or less isn't going to have as big an effect on contrast as with the Xtol negative. The two curves also illustrate why it's not a good idea to use percentages to communicate changes in development time.

 

[rbultman]

I wouldn't get too hung up on this. There are a lot of "if"s (variables such as the ones PE listed). Multiple contrast printing throws additional variables into the mix.

I assume by "split grade" you're referring to the practice of splitting the base print exposure into two parts - one with minimum contrast filtration and one with maximum contrast filtration. Yes this can affect the total exposure time in different ways. For example, high contrast filtration typically reduces paper speed, so depending on how you end up dividing the base exposure into high and low contrast exposures, the total time could change. Not a problem though.

Apologies for barging back into the thread, but since the discussion has evolved to include printing (and it should!) I couldn't resist.

Not sure what you mean by barging in! We have completely crashed this party!

Yes, I meant split printing as per Anchell's The Variable Contrast Printing Manual, Chapter 6.

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