Hp5 at ASA 141???

[neil poulsen]

Perhaps, but my tests in daylight have produced results similar to Neil's. I shoot HP5+ at 160 (unless I'm shooting handheld). With FP4+, oddly enough, I can shoot at box speed. Same process for both films, using Xtol 1:1 at 24C.

That's interesting about FP4. I'm itching to give this film a try. If so, I may not have to take too much of a hit in speed.

My film speed test target is about 6" in diameter cut in a largish sheet of plywood. I place a sheet of translucent white plastic against this and follow with a sheet of frosted glass 3/4" behind that. I illuminate this target from behind with two blue bulbs. I can change the intensity of the target by varying the distance between the bulbs and the target. (Or, by turning off one of the light bulbs.)

[djdister]

Given your results for HP5, you should definitely consider either FP4 or Delta 100.

[Brian C. Miller]

Neil, what is your take on Paul Wainwright's zone method? (PDF link)

[Stephen Benskin]

[jnantz]

I thought that I would do a sanity check; mine!

But before you render an opinion, let me explain . . .

I just completed a speed test for Ilford's HP5, and determined that the speed of my box of film is ASA 141, which is a half-stop better than ASA 100, and of course a half-stop worse than ASA 200.

Is this consistent with the results that others have obtained? Normally, I come up with ASA 200, so I guess it isn't so far off of typical. But, I thought that I would check.

I've accurately taken into account bellows expansion and actual shutter speed. My FB+F was 0.08, and my target was 0.18. I checked my densitometer with a Stouffer's standard that I keep on hand, and it's accuracy appears to be satisfactory.

neil

have you used this film in a non-controlled-atmosphere yet ..
i mean in a non film test / situation shooting outside
or wherever / whatever you like to shoot ?

and did your "real life" ( non-controlled-lab ) results
jive when you exposed your hp5 at iso 141 with your
processing-situation ? or was your film over / under exposed ?

john

[Regular Rod]

Doesn't all this depend on what you choose to meter on in the subject?

RR

[IanG]

Doesn't all this depend on what you choose to meter on in the subject?

RR

When you do a speed test you use a reference point (it might be an 18% grey card) and you work from there. It's slightly different to metering an image in real life, which John is alluding to.

There's no totally definitive method, The Minor White/Adams method of Zone System testing differs slightly from the British approach used by John Blakemore, Peter Cattrell, Fay Godwin, John Davies etc - we tend to print slightly a bit flatter in the UK, with a longer tonal range. Actually if you look at Ansel Adams work his later prints (even off early negatives)n were much more tonal.

Ian

[Kevin J. Kolosky]

best thing to do now is go out and shoot some long scale, short scale, and medium scale subjects, using your tested ISO and a few other ISOs and then contact print all of them at the same time, which would be the time for the film base to just turn black. develop all the same. see what you have and go from there.

[neil poulsen]

Neil, what is your take on Paul Wainwright's zone method? (PDF link)

I read over the portion that discussed exposure index. One thing, he presents a method that doesn't require a densitometer. Personally, I HAVE TO HAVE a densitometer. If I didn't have one to do calibrations, I'd start twitching. In full disclosure, I'm a statistician, so I LOVE DATA. And, my densitometer isn't that great. I spent $100 for it years ago, and until I received it, I wasn't that certain that it worked. But from an old Stouffer test negative that I have, it gives me fairly accurate results in the lower regions, and it gives me comparative values above that. By comparative values, I need to only be confident that densities are the same in two different negatives.

But also, I don't think that it was without consideration, that Ansel Adams recommended the 0.1 density units above FB+f. I'd be interested in the views of others on this; but, I think that at stake in selecting this standard (0.1) are both detail in the shadows and detail in the highlights. The higher this number, the less room at the top for the highlights. So, the 0.1 standard is a compromise between room at the top and room at the bottom. In recommending an ASA of 200, Wainright isn't that far off. That's what I typically get. But, I think that it's best to have data to know for sure. In this case, I believe that my lower than typical results can be traced to a combination of using blue bulbs and using a Zone VI modified meter. Apparently, my testing with data took this into consideration.

As for determining development times, he uses a method that lends itself to visual examination. For example, to get an N-1 development time, he would lower the development time until he sees detail in a Zone IX exposure.

I would call this an "absolute" approach, where mine is more a "relative" approach. For the same result, I would first determine an enlarger exposure time for maximum paper black (as Wainright does), and then use visual examination to select a film density that gives me a Zone VIII that I like. This would by my "N" development. (I use Zone VIII for an "N" development; Ansel Adams recommended Zone VII for an "N" development.) Thereafter, I would use comparative readings to find a Zone IX film density that gives me this same value for an N-1 development. And, so on and so forth.

In summary, I would say that Wainright's approach, and his recommendation of using ASA 200 for an ASA 400 film, is based on a solid understanding of how B&W film behaves. His "absolute" approach lends itself to visual examination, where one might not have a densitometer. But, it's a bit squishy for me and includes sources of variability that I can avoid using a densitometer. Besides, I LOVE DATA!

[neil poulsen]

neil

have you used this film in a non-controlled-atmosphere yet ..
i mean in a non film test / situation shooting outside
or wherever / whatever you like to shoot ?

and did your "real life" ( non-controlled-lab ) results
jive when you exposed your hp5 at iso 141 with your
processing-situation ? or was your film over / under exposed ?

john

Of course, the real test is in how prints come out. The reason I migrated to using blue bulbs, was because I wasn't getting the results I wanted in the field.