Anyone used Fomapan sheet film?

[Bip]

It's very economical price compared to the bigger brand names!

Bip

[Joanna Carter]

It's very economical price compared to the bigger brand names

But have you seen the reciprocity figures? http://www.apug.org/forums/forum37/4934 ... ilure.html e.g. a 10 second exposure ramps up to 90/60/80 seconds, depending on the film version.
Take a look at Fuji Acros 100 - no correction up to 120 seconds, 1/2 stop up to 1000secs.

IT would seem you might get what you pay for

[IanG]

I've been using the Fomapan 100 & 200 in 5x4 and 9x12, as well as 120.

They are both excellent films for LF work, but you need to do some tests to find the best EI and dev times for your way of working.

I use both at half the box speed, and also give approx 2/3rds the development I use for Delta 100/400 etc. They build up contrast very rapidly with under exposure and over development.

So far I've not had an issue with reciprocity.

Ian

[Mike M]

Totally agree with Ian.
I've used Foma 100 for the last 6 months and found it a very good film but like Ian says you will need to make thorough EI tests.
I was developing it in Rodinal rated 80asa with a standard development time of 8 minutes. I've now changed to rotary developing my film so this would make my N-2 times way too short for my liking which is the only reason I changed film.
My solution to its reciprocity problem...keep a film holder loaded with HP5+.


With regards to Acros, I've heard it is a very good film and I have been tempted to start using Quickloads but its just sooooooo expensive!!

[richard littlewood]

Mike. Just out of interest what are you rotary processing your Fomatone in?. Only asking because I've got hold of a good amount of the 100 in 5x4, and as I'm normally an FP-4/rotary/ID-11 user I'm planning doing the same with the Foma.
Like to hear any thoughts on this film, especially as to how it gets on with contrast filters.
Cheers
Richard

[IanG]

Just did some practical tests and Fomapan 200 is nowhere near as bad as the Foma data sheet.

I found it only needed a half stop extra at 1 second and a full stop at 10 seconds which is quite manageable.

I still need to do further tests, but at Foma's suggested times the negatives were over-exposed, and the 10 second tests at 1 minute & 2 minutes very extremely over-exposed, Foma recommend 90 seconds.

Ian

[richard littlewood]

Ian. Interesting. I've just got off the Foma site looking at reciprocity info for Fomapan 100, and going by the info there 100s = 1600s. Thats a lot more. After reading your last post on the 200 film I've decided not to use the 100 film as I planned to do this evening and go with some Delta instead - tests ahead for the Foma.

[IanG]

Richard, I very much doubt the Foma figure, of a 100 second exposure needing 1600secons because of Reciprocity, is right, based on my first findings.

Howard Bonds figures for Delta & Tmax films are in line with my own experiences shooting in very low light levels, and the figures are well below Ilford's recommendations.

But this raises a separate issue. If you meter reading is 2 minutes (120 seconds) assuming you're shooting at f22 that's the same as 8 seconds at f5.6 or 1 second at f2.

So for instances shooting LF & stopping down to f22 & a 2minute exposure is significantly different to a 35mm/120 user shooting at f4 with a 2 minute exposure, there's five stops difference in light levels. For this reason companies like Ilford only publish very generalised reciprocity tables.

The only sure method is practical testing to see how a film behaves under the conditions etc you want to work in.

Ian

[Joanna Carter]

Ian, I have edited your first post to correct it, which is something you can do yourself

[IanG]

Thanks Joanna, but the edit button had disappeared

I referred to the Howard Bond article earlier in this thread thinking it was in the APUG thread quoted. In fact it was in a separate thread so here's the link.

Howard Bond article on Reciprocity

It's worth reading

Ian

[Jonathan Perkins]

Hi Ian,

So for instances shooting LF & stopping down to f22 & a 2minute exposure is significantly different to a 35mm/120 user shooting at f4 with a 2 minute exposure, there's five stops difference in light levels. For this reason companies like Ilford only publish very generalised reciprocity tables.

I don't quite understand your interesting comment here. Surely if the LF user metered 2min at F22 and the SF user 2min at F4, the total light energy available inside the camera over the 2 minute period would be the same, regardless of the outside light levels (on the grounds that I don't have to tell my light meter the size of film I am using!)?

As a lapsed physicist I thought I had a (very) vague idea of why reciprocity failure occurred, but now I'm a bit confused

Jonathan

[Paul.]

Hi Ian,



I don't quite understand your interesting comment here. Surely if the LF user metered 2min at F22 and the SF user 2min at F4, the total light energy available inside the camera over the 2 minute period would be the same, regardless of the outside light levels (on the grounds that I don't have to tell my light meter the size of film I am using!)?

As a lapsed physicist I thought I had a (very) vague idea of why reciprocity failure occurred, but now I'm a bit confused

Jonathan

But they would not be metering the same light, if the SF user needed 2min at f4 then he would have 5 stops less light than the LF user who needed 2min at f22. We stop down to f22 for depth of field reasons and therefore have to extend our exposure time, where as a SF user would have sufficent DOF at f8 and would therefore need less exposure than the LF user if they were stood together shooting the same shot.
My understanding of resiprocity failier is extreamly basic and I equate it to the power band of an engine from idle to on cam is a gentle curve, on cam in the power band a fairly liniar rise , once past peak power the curve tails off, as the curve tails off it takes longer to generate the power until the point where no more power is possible, reciprocity failier. Very aproximate and very un sceintific but helps me understand why I need to give film more time, how much and when is down to manufactures info and experiance, mine and others, some times I even get it nearly right. Regards Paul.

[Jonathan Perkins]

Hi Paul,

But they would not be metering the same light, if the SF user needed 2min at f4 then he would have 5 stops less light than the LF user who needed 2min at f22

Yes, I agree the LF user has more light outside the camera, but by using f22 instead of f4 they attenuate the light entering the camera by 5 stops more than the SF user. So the light energy inside the camera (and therefore reaching the film) should be the same. I'm worried now that I've missed something rather basic here!

My understanding of the cause of reciprocity failure is that it takes a certain number of photons to reach enough energy to activate the chemical reaction required to record a latent image, and that under low light levels this energy is not always met in time (if the photons arrive with some randomness) so that the change does not always happen - hence needing to extend the exposure time. I'm hoping Ian might be able to shed some light on this (groan! ).

Jonathan

[Paul.]

Hi Johnathan,
If one camera has an iris opening of f22 for 2 min it will let in x amount of light.
If the same camera has an iris opening of f4 for 2 min it will let in 5x amount of light, as f4 is 5 times larger than f22.

So if in the first example the iris alowed say 10 lux ( measurement of light ) into the camera then in the second example the iris would alowe 10 x 5 =50 lux into the camera.

Regards Paul.
p.s. have just reread Ians post and I do not think he was sugesting the same lighting levels in both cases.

[Jonathan Perkins]

Hi Paul,

p.s. have just reread Ians post and I do not think he was sugesting the same lighting levels in both cases.

Yes thats what I understood - I thought he meant that the metered exposure not allowing for reciprocity failure was 2mins in each case, the difference in light levels being balanced out by the same number of stops difference in aperture.

The reason I'm interested is that like Bip (sorry for hijacking the thread) I've been looking at the Fomapan with interest because of the much lower cost, but was concerned about the reciprocity until I read Ian message about his actual tests - those results look very manageable (but my curiosity was triggered by trying to understand why they might be so different from the published specs).

Jonathan