Long Exposure - Very Different Results Between Digital and 4x5 Film

[secondhandrobot]

The Reciprocity Timer app makes these calculations simple.
135mm lens at 210mm means you add 1.33 stops.
For Foma 100 with a metered exposure of 3 mins and 20 secs (the closest the app has to your time) the recommended exposure time is pretty much 4 hours.
For Fuji Acros 100 the exposure time would be 13 minutes.

Wow. 4 hours vs 13 minutes. That illustrates the point pretty well I would say. I guess that is one reason why Fomapan is so cheap.

As a beginner I was just trying to find the cheapest possible film to start with.

Will definitely try the Fuji Acros 100 in the future.

[pdh]

There are a lot of back of the envelope arithmetic on show in this thread, but not so much personal experience.

Forum member IanG uses Fomapan 100 a lot, and I have seen many posts by him (mostly at APUG) suggesting that reciprocity failure is nowhere near as bad for Foma 100 as is suggested even by Foma's own data sheet.

One thing I notice is that the OP seem to be using artificial lighting, and this is will have an effect too. The spectral response of Fomapan 100 might be a poor match to the output from his lighting.

All films have different characteristics, and Acros is very unusual in its even reciprocity over long exposures. Foma make excellent films, and the fact that they don't match Acros in their reciprocity characteristics doesn't make them poor, it simply makes them a less good choice if reciprocity at long exposures is important.

[StoneNYC]

There are a lot of back of the envelope arithmetic on show in this thread, but not so much personal experience.

Forum member IanG uses Fomapan 100 a lot, and I have seen many posts by him (mostly at APUG) suggesting that reciprocity failure is nowhere near as bad for Foma 100 as is suggested even by Foma's own data sheet.

One thing I notice is that the OP seem to be using artificial lighting, and this is will have an effect too. The spectral response of Fomapan 100 might be a poor match to the output from his lighting.

All films have different characteristics, and Acros is very unusual in its even reciprocity over long exposures. Foma make excellent films, and the fact that they don't match Acros in their reciprocity characteristics doesn't make them poor, it simply makes them a less good choice if reciprocity at long exposures is important.

Yes Foma has its place, it's not a BAD film, just poor reciprocity.

However I would disagree with the statement that the times aren't as bad as Foma lists, I think they are worse.

I've had to do 2+ hour exposures and actually done them, and the negatives were very thin, I checked my exposure times along the way to make sure I didn't have to adjust further, and so the exposure should have been correct but the negative was super thin.

So maybe Ian is only shooting 10 minute exposures but for hour long exposures I would give a full stop MORE exposure because in my experience foma needs it.

Again, everyone's methods are different.

I do agree with the spectral response comment, artificial non-Tungsten light will give probably poorer results, especially on Foma, which I believe is made for daylight situations.

I personally promote Fuji Acros100 because I wanted to stick around, I shoot it in 4 x 5 and 8 x 10, and I think the more people that use it the longer it will be around, it's also the best for reciprocity in terms of ease-of-use even on short term exposures like one minute or 30 seconds etc.

However there are other excellent feelings and you also have to take into account the speed of the film.

Another great film for long exposures is TMY-2 (Kodak Tmax400) which is a 400 speed film versus Acros100 which is a 100 speed film, even though TMY-2 has to be adjusted after one second in terms of reciprocity, the adjustment is small, and because it's TWO STOPS faster than Acros100, you are starting your adjustments from "farther down" in the timeframe so to speak.

A 2 second exposure with Acros100 is only a 1/2 exposure with TMY-2 no exposure adjustment needed.

A 1 minute exposure on Acros100 is a 15 second exposure with TMY-2 (plus adjustments for reciprocity probably 20 seconds ... I didn't look just guessing) so in that case TMY-2 is actually better.

However as you get to the 2, 3, 5, 10 minute range, they even out and are pretty much the same give or take.

Ilford HP5+ is also a 400 speed film, more grain, but a lot cheaper in the USA than either of the other films. Not as good reciprocity as TMY-2, but much better than FOMA, so it's a good compromise.

In Europe I believe the price of Ilford films is higher and Foma is lower.

Many options to choose from, but personally I try to stick to Acros100 whenever possible

[secondhandrobot]

Yes Foma has its place, it's not a BAD film, just poor reciprocity.

The Fomapan is the first box of new large format film I have ever bought. Up until then I had been using old Ilford FP4 that I think expired mid 1980s.

Compared to that old Ilford the Fomapan seems like premium deluxe film.

[Bob Sawin]

Recording an image on a sensor is akin to recording an image on color transparency film. And you are using b+w film.

[Lenny Eiger]

Compared to that old Ilford the Fomapan seems like premium deluxe film.

If you want to look at a real premium film, try Ilford's Delta 100. Soup it in some Pyrocat HD.... you'll be amazed.

It takes good materials to learn. Better to use a premium film and premium developer and tune your development times to exactly what you need. The amount of extra cost is minimal over time, and you will have an experience of what's possible.

[StoneNYC]

If you want to look at a real premium film, try Ilford's Delta 100. Soup it in some Pyrocat HD.... you'll be amazed.

It takes good materials to learn. Better to use a premium film and premium developer and tune your development times to exactly what you need. The amount of extra cost is minimal over time, and you will have an experience of what's possible.

They also mean old Ilford, the "non-plussed" version

[Lenny Eiger]

They also mean old Ilford, the "non-plussed" version

Yes, I did catch that... old and expired. I actually liked FP4 not plus much better than the plus. I used a lot of it and had great results. Never tried it expired for however many years, tho'.

Film has definitely changed over the years, but TMax, TMY2, Acros and Delta are all excellent. I have always liked Ilford and Delta is every bit as good was TMax, its a little less expensive, so that's what I have been using lately. The more I use it, the better I get.

My real point was while it may be fine to learn how to develop film with cheap stuff, that once you have learned its better to use good materials so that if you actually do take a good photograph you have something you can use rather than some image on some cheap, junky film that you have to struggle to get a decent print out of....

Lenny

[Drew Wiley]

I recommend learning with a good versatile film you might stick with in the long run, at least once you're beyond the basics of focus, movements, lens selection etc. It takes awhile to readjust. And you never know... you might just bag an interesting shot early on that you wished you had gotten on better film. ACROS is
certainly the most versatile with respect to reciprocity characteristics at long exposure, followed by TMax films. I'm in the "don't like" camp with respect to Delta
sheet film, though I will admit the quality is high. I personally find FP4+ to be way more versatile among Ilford choices, or HP5 when you need speed. TMax films are more fussy with respect to exposure and a bit pricey, but quite rewarding. I shoot a lot of TMY400 in 8x10; but ACROS is probably my favorite 4x5 film at the moment. Everybody has their own specific reasons for favorites, due to their own subject matter and desired look. There are a lot of good choices out there at the moment. But one axiom I have learned over time the hard way is that the most economical film is the one which does the job right the first time,
and not necessarily the once whith the cheapest price tag on the box.

[miltonkeynes86]

Hi All - Newbie here.

I have a question I thought some of you might be able to help me with.

I am trying to do some still life shots in very low directional light. In other words lighting the subject only, say an apple or a shell or something.

I did some test shots on my Nikon digital camera at f 29 @ 120 seconds @ 100 ISO. Shots came out well lit, could see what the object was and even the background was well lit and clear.

I then tried to translate those settings to my new Toyo 45A which I currently have loaded with Fomapan 100. After reading about Fomapan 100 I am using it as ISO 80.

So my translated settings (using my handy android ev pairs app) for f 32 came to:

f 32 @ 3.2 minutes = 3.12 minutes @ ISO 80

After developing the shot, for example of the shell, the film was almost totally clear. I could just see a few details from the lines of the shell. In other words very very underexposed.

So the question is why is there so much difference between the digital and film results?

And how can I accurately determine long exposure shots when using my Toyo / Fomapan 100 if I cannot simply translate the settings from my digital camera meter?

I guess its worth pointing out that on faster shots in well lit situations the results are fine and I can meter with my digital without the vast difference in results.

Thanks

This will be abstract until you read up on reciprocity failure with film.