Question On Subject Brightness Range

[David Schaller]

6 stops (11,12,13,14,15,16)

Am I correct in thinking that you are removing the bottom and top reading which ends up as 4 stops.

You are then adding this to 5 to get the 9 stop SBR and applying N-2 to bring it down to the 7 stop Normal range.

Do you always use this approach whether you are using a spot meter or incident meter.

I'm used to basic Zone system thinking,whitch would be that if the shadow is Zone III, there would be two darker zones below it (above B+F), which is why I said assuming the shadow is Zone III.

From a practical point of view, using his EV measurements, if EV 10 is placed in Zone III, the exposure would be made on EV 12, and I would develop the EV 16 highlight N-2, to bring it down to Zone VII. Other people would think this is overly conservative, but I prefer to reduce contrast in the negative rather than in the print, where I can always add it back easily if I want to.

[Ted R]

If a subject has a low reading of 10 EV and a high reading of 16 EV, is the SBR for this subject 7 stops (10, 11, 12, 13, 14, 15, 16) or 6 stops (11,12,13,14,15,16)

When the two readings are 10 and 11 the range is one stop. 10 and 12 two stops. 10 and 13 three stops. 10 and 14 four stops. 10 and 15 five stops. 10 and 16 six stops. Answer six stops.

[Doremus Scudder]

If a subject has a low reading of 10 EV and a high reading of 16 EV, is the SBR for this subject 7 stops (10, 11, 12, 13, 14, 15, 16) or 6 stops (11,12,13,14,15,16)

Subject Brightness Range has to do with the total range of light reflected from the subject from its lowest to its highest. Where those things get placed depends on what the photographer wants from the final print.

Placing, say, EV 10 on Zone III implies that there are at least Zones I and II below it, since Zone III is a "light black" value with detail. No Zones I & II = no detail in Zone III.

However, the OP is just giving us values read by a spotmeter, from lowest to highest. If we assume that the low value of EV 10 is Zone I, then EV11 would be Zone II, EV 13 would be Zone III, etc. up to EV 16 falling on Zone VII. As far as I'm concerned, that is 7 Zones and a 6-stop spread.

The confusion in this thread comes from two sources. One is that a "low reading" with a spotmeter in Zone System usage usually means that it is placed in Zone III, therefore implying that there are two "phantom Zones" below it, thereby expanding the total SBR to 9. If this, indeed is what the OP meant, then this is, indeed, valid.

Another source of confusion is the BTZS method of using incident readings taken in shade and direct sunlight. An incident reading assumes all Zones in flat lighting, i.e., around 5-6. The difference in the two incident readings shows the difference in illumination and the amount of "Zones" that need to be added to a single incident reading. For example, if there are three stops difference between the low and high incident readings, then we expand the number of Zones expected in the scene to 8-9. This would indicate a reduced development from "Normal."

@OP: If you're using the Zone System, quit worrying about SBR and worry more about careful placement of shadow values and then where the other values fall after you've arrived at that. This latter will determine your choice of development time. We Zonies talk more about "spread" and less about SBR, which is more at home in BTZS parlance. E.g., from Zone III to Zone VIII is 6 Zones and a 5-stop spread. Think of spread as the difference and the number of Zones as the total number of "stripes" or "positions" from top to bottom.

Best,

Doremus

[Peter De Smidt]

This is just a personal preference, and it likely depends on the type of light where I photograph, but I don't generally like minus development, as it leads to diminished separation of tones, and many modern films don't shoulder until extremes of exposure are reached. If the subject has a huge luminous range, I'd rather do divided development with Pyrocat than a traditional minus development.

[Vaughn]

I wrap my mind around it about the same way as Doremus -- I think.

If I took those reading on my Pentax Digital Meter (10 to 16), I would think I got 7 zones represented here...measuring the darkest value I can find, then up to the highest value I can read in the scene. But I would also call it a 6 stop range. If I wanted detail in the areas I metered as 10, then I would expose at 12. My exposures are usually long -- so I may or may not fully correct for reciprocity failure depending on the scene and my contrast needs. If I am not hording film, I will usually take a 2nd exposure at the same or at one stop more exposure -- developing the second based on the first.

In my field notes, I'll denote of the range of my readings of the scene and where my exposure(s) falls in that range. Back at the ranch, I can find like-minded sheets of 8x10 and develop them together in an Expert 3005 Drum. In this particular situation (6-stops and/or 7 zones) I would give the film extra development to boost the contrast for alt printing -- with how much 'extra' depending on the process.

I'll be developing some 4x5 Ilford Ortho Plus, rated at 50 ASA, tomorrow. Some 6-stop range (metered 7 to 13) scenes and some 8-stop range (metered 5 to 13) scenes to work with (an old hallowed hall at Cornell University, and some gorge in central NY, respectively).

The Ilford Ortho is tricky stuff...trying to control it it in my usual haphazard fashion has not been easy. On earlier attempts I aimed for platinum/palladium quality negatives, but I over-did it and the negatives' contrast was too high for Pt/pd; but a great fit for the carbon process! The Ortho Plus is proving as interesting to work with as the Tech Pan I am running out of. I am field testing it for an on-going project in the redwoods. The project will be carbon prints, but I am testing its limits (or they are testing me!) and looking for some finer control.

Peter -- that is what originally drew me to carbon printing...not having to compress the light to match the material.

[IanBarber]

@OP: If you're using the Zone System, quit worrying about SBR and worry more about careful placement of shadow values and then where the other values fall after you've arrived at that. This latter will determine your choice of development time. We Zonies talk more about "spread" and less about SBR, which is more at home in BTZS parlance. E.g., from Zone III to Zone VIII is 6 Zones and a 5-stop spread. Think of spread as the difference and the number of Zones as the total number of "stripes" or "positions" from top to bottom.

I think this summed it up nicely, thank you

[Bill Burk]

If a subject has a low reading of 10 EV and a high reading of 16 EV, is the SBR for this subject 7 stops (10, 11, 12, 13, 14, 15, 16) or 6 stops (11,12,13,14,15,16)

You've gotten many thoughtful answers about how to interpret your readings... I don't want to detract from that.

But let's say you decided the two points on which you want to determine the subject luminance range are 10EV and 16EV.

The simple answer to your question is to count it as 6 stops of range. The stop from 10 to 11, then to 12, 13, 14, 15 and 16

[interneg]

I'll be developing some 4x5 Ilford Ortho Plus, rated at 50 ASA, tomorrow. Some 6-stop range (metered 7 to 13) scenes and some 8-stop range (metered 5 to 13) scenes to work with (an old hallowed hall at Cornell University, and some gorge in central NY, respectively).

The Ilford Ortho is tricky stuff...trying to control it it in my usual haphazard fashion has not been easy. On earlier attempts I aimed for platinum/palladium quality negatives, but I over-did it and the negatives' contrast was too high for Pt/pd; but a great fit for the carbon process! The Ortho Plus is proving as interesting to work with as the Tech Pan I am running out of. I am field testing it for an on-going project in the redwoods. The project will be carbon prints, but I am testing its limits (or they are testing me!) and looking for some finer control.

I've found Ortho+ pretty easy to control - that said, the ability to fairly easily DBI the stuff is handy...

What are you developing it in?

[Pere Casals]

If a subject has a low reading of 10 EV and a high reading of 16 EV, is the SBR for this subject 7 stops (10, 11, 12, 13, 14, 15, 16) or 6 stops (11,12,13,14,15,16)

It depends on how you meter. An EV value has a brightness range of 1 EV, with a low point, a center point and a high point.

From the center of 10 EV to the center of 16 EV we have 6 stops.

From the lowest point of 10 EV to the highest point of 16 EV you have 7 stops.

From the highest point of 10 EV to the lowest point of 16 EV you have 5 stops.


So true Dynamic range will depend on if you have spots in the limits of the zones or not.

If textures in 10 EV and 16 EV are important then better to consider you have 7 stops range, if no important textures (washed sky...) in the extremes you can consider 6.


You got different answers from different posters because that. A metering system is a practical simplification that works very well, the exact way is using a sensitometric curve, calibrating your personal process: Lux*second vs density!!!


Regards.

[Stephen Benskin]

Thanks Bill for using the term Subject Luminace Range.