FP 4 reciprocity.
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I have one and it is at the darkroom and I will get it for you and post it for your tomorrow.
lee\c
lee\c
I have no reciprocity data for FP4+, only anecdotal observations.
This has quickly become one of my favorites for nighttime photography. I prefer it in Diafine for that usage.
The maker of Diafine suggests an EI of 250 for use with FP4+. Instead, for nighttime use I halve that and rely on my F3HP's AE mode to establish a baseline exposure. I also estimate exposure based on the EV for a given scene (metered when possible, estimated otherwise). From there I'll bracket in full stops one up and one down.
So far this has given me at least one and usually more than one usable exposure. I simply treat the lighter or darker exposures as different interpretations of the scene.
For 35mm or rollfilm use I believe this is a viable method if you have enough time. If you're using sheet film or time is short and you can't bracket, by all means you'd want the reciprocity data.
This has quickly become one of my favorites for nighttime photography. I prefer it in Diafine for that usage.
The maker of Diafine suggests an EI of 250 for use with FP4+. Instead, for nighttime use I halve that and rely on my F3HP's AE mode to establish a baseline exposure. I also estimate exposure based on the EV for a given scene (metered when possible, estimated otherwise). From there I'll bracket in full stops one up and one down.
So far this has given me at least one and usually more than one usable exposure. I simply treat the lighter or darker exposures as different interpretations of the scene.
For 35mm or rollfilm use I believe this is a viable method if you have enough time. If you're using sheet film or time is short and you can't bracket, by all means you'd want the reciprocity data.
Jorge
I have been told by a reliable source from Ilford that to get the correct exposure on FP4 when under reciprocity failure conditions that you multiply the selected exposure time (in seconds) to the power of 1.49. So if you have a decent scientific calculator or an excel spreadsheet why not create your own table
Excel formula =POWER(A2,1.49) where A2 is the time in secs
Phill
I have been told by a reliable source from Ilford that to get the correct exposure on FP4 when under reciprocity failure conditions that you multiply the selected exposure time (in seconds) to the power of 1.49. So if you have a decent scientific calculator or an excel spreadsheet why not create your own table
Excel formula =POWER(A2,1.49) where A2 is the time in secs
Phill
philldresser said:
That is close to the SQRT of 2 (1.41 et c.). I have been using that (SQRT 2) as a guidline for years. I discovered the same factor is useful in determining zone development times. Maybe a paper is in order? Ever notice the frequency of occurrence of this factor in photography and optics?
How about the Ilford site and the chart on page one for FP4plus?
http://www.ilford.com/html/us_english/pdf/FP4Plus.pdf
Is there something more you need? I seems to be such an obvious source that I must be missing something. Is new FP4plus a lot different than FP4?
http://www.ilford.com/html/us_english/pdf/FP4Plus.pdf
Is there something more you need? I seems to be such an obvious source that I must be missing something. Is new FP4plus a lot different than FP4?
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The Ilford chart you mention is what I have used in the past with terrible results, and from what I understand I am not the only one. In addition it only goes to 30 seconds exposure. I am guessing the place I want to photographs will have soemthing in the 2 minute range for which I will have to compensate for reciprocity. While I am sure that FP4 and FP4+ would probably behave very similar at these exposures, when you are doing 12x20 it pays to be as accurate as you can...
BobF said:
I just love it when I'm right!
Bob
For a 1-7 sec exposure I DOUBLE the indicated time on the meter.
For 8-59 seconds I QUADRUPLE it.
For 1 min plus I multiply by EIGHT (from a table published in Photo Art a few years ago). This has served me well for several years and I'm very happy with the negs-a touch dense sometimes but if it's not on the neg you can't print it can you ? I've generally used FP4/HP5 or Fortepan in 4x5 devved in PMK or a 2 bath.
For 8-59 seconds I QUADRUPLE it.
For 1 min plus I multiply by EIGHT (from a table published in Photo Art a few years ago). This has served me well for several years and I'm very happy with the negs-a touch dense sometimes but if it's not on the neg you can't print it can you ? I've generally used FP4/HP5 or Fortepan in 4x5 devved in PMK or a 2 bath.
Jorge,
This is what I have:
meters reads shoot at
1 1
2 3
3 5
4 8
5 11
6 15
7 20
8 25
10 35
12 45
15 60
30 2m40s
45 7m
60 10m
2m 15m
These work very well. There is some thought that you don't need to change the development with the Ilford products like you do the Kodak stuff. I think I might do that to about 20%. After that I would not fool with it if it were me.
lee\c
This is what I have:
meters reads shoot at
1 1
2 3
3 5
4 8
5 11
6 15
7 20
8 25
10 35
12 45
15 60
30 2m40s
45 7m
60 10m
2m 15m
These work very well. There is some thought that you don't need to change the development with the Ilford products like you do the Kodak stuff. I think I might do that to about 20%. After that I would not fool with it if it were me.
lee\c
no hay problemo senor
lee\c
lee\c
I printed it out and had it laminated and keep it in my shooting vest. I have HP5+ the delta films an d tri-x tmx and tmy on the same chart. BTW, the chart I posted for you will work for Pan-F also.
lee\c
lee\c
I suppose there's a similar way of calculating for Ilford Ortho Plus IF the number were available? That would be so helpful. I'd much rather use the formula than a graph. fwiw, I have searched the internet and have found very little regarding this film and its' reciprocity
Thanks,
Dorothy
Wow this is an old thread. I don't even think that Jorge is doing photography anymore.
That's a shame, I always enjoyed the posts.
It says he's inactive here. Same over at large format forum. I think I recall he gave up photography for carpentry...
Well woodn't you know it.............Wood... get it
So he gave up trying to control dust and opted to start creating it ?
You could look at it that way...
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