New LF B&W User Question - Tray development of 5x7 Ilford FP4?

[Magpie]

Hi All,

I am in the process of setting up to shoot 5x7 B&W and came across a mention on Michael A Smith's Website that they develop their film 'by observation'. I know they use an old Kodak film that is no longer available but was wondering if it is possible to develop Ilford this way?

It is many many years since I did any darkroom work and hope to flatten the learning curve a bit, I am just glad I was pointed to your site by a friendly LF user (and aren't they all?).

Any help/advice gratefully reveived.

Regards

Brendan

(coming back from the d****** dark side)

 

[Ole]

I do most of my LF developing that way - including 5x7" FP4+.

It's easy, but takes a little practice to judge when the negative is "done". There's also quite a big difference between developers as to how the negative looks, so don't assume advice for one developer can be used with another!

PS: Welcome back to the "dark slide"!

 

[eumenius]

Hi Magpie,
I think Michael A. Smith meant a development with visual inspection, and with FP4 you'd need a desensitizer (for example, phenosafranin or pinacryptol) and a deep green light for it. Desensitization development requires also good experience in it, so you'll able to understand in a dim light if everything has developed to the right amount. In my eyes, all this fiddling with panchromatic film is just not worth the work - if someone measures light well, and correctly develops the film by time, he doesn't need to bother with any desensitizers. The risk of fogging with desensitized films is also higher. I just recommend you to calibrate your system (film, developer, camera and meter), using the suggested by factory values as a starting point, and be happy with your film tray-processed by time It's way easier and allows to concentrate more on a shooting technique, not on a negative salvation

Cheers from Moscow, Zhenya

 

[Ole]

... with FP4 you'd need a desensitizer (for example, phenosafranin or pinacryptol) and a deep green light for it. ...

I have found that desensitizer is not necessary. The light should be very weak, but doesn't necessarily have to be green either (although the eye is most sensitive in the green rgion, it makes no difference to the film).

After five minutes in "total" darkness the eye is far more sensitive to light than a film that's been in the developer for those five minutes, and it takes a surprising amount of light to fog it.

 

[matt miller]

I agree with Ole, that a desensitizer is not necessary. I use a red safelight to check my negs, some use a green safelight, some use night vision equipment, some use the light leaks in their darkroom. For me, red is better when I use TMY in pyrocat.

What developer do you plan to use Brendan? How will you be printing the negs? Silver, pt/pd?

 

[removed account4]

hi there

i don't use a red safelight, but a DARK GREEN one.
with the room lights on, it almost looks nonexistant, but
with the darkness, it is bright.

good luck!

-john

 

[Magpie]

What developer do you plan to use Brendan? How will you be printing the negs? Silver, pt/pd?

Hi Matt, I intend to contact print on AZO or similar, have not got the chemistry sorted out yet but I am thinking probably Pyro. I have a couple of books on the way from the states and will read up on that side of it.

My reason for asking the question above is that I will be using a dark 'cupboard' about 1.2m x 1.3m and need to plan it out - space is critical with such a small area available and I am trying to get my head around the best way to do things.

It doesn't help that I am starting again getting all the darkroom stuff together

Regards

Brendan

 

[gainer]

Pyro developers have a reputation for being friendly to development by inspection. The pyro desensitizes the film considerably. Be sure you protect your skin from prolonged contact with pyro.

Pan film has a much wider spectral response than the eye, which peaks in the green. The film sees more of the spectrum of an ordinary incandescent bulb than does the eye, so that filtering the light to give a pass band at the peak of the eye's response gives maximum exposure to the eye and minimum to the film for a given degree of visibility.

 

[Ole]

A few more points:

Early "panchromatic" films had a "dip" in the sensitivity in the green region. This was exploited for DbI.

Developer in a tray will oxidise and turn brown, which will filter out green light with a fairly good efficiency.

The eye has two kinds of light-sensitive cells, called "rods" and "cones". The rods are your low-light vision, and have a sensitivity that peaks around 498nm - green.

Astronomers, back in the days when "astronomy" meant peeking through a telescope, would use red light for "non-peeking" for exactly the same reason: Since red light is outside the rods' sensitivity, a brief exposure to red light will not affect night vision...

Not all films are equal: Efke PL25 and 50 have reduced sensitivity in the red region, which means that a deep red filter might make more sense for these films (and see "astronomers" above).

Rods are not very "sharp": It' almost impossible to make out details in faint green light. Cones (the colour-sensitive thingys) are "sharper", so if you want to see details and not just overall contrast red might be better.

Ilford's FP4+ has reduced blue sensitivity (compared to other pan films), but noone has suggested using blue light for DbI with this?