besides TMAX, are there any other films that can NOT be developed by inspection?

hi

 

i have never had a problem developing tmax by inspection. i guess i am lucky ...

 

i just learned today that increased red spectral sensitivity makes the tmax family of

film fog if developed by inspection.

 

are there other films that manufactures recommend NOT to develop by inspection?

 

thanks

 

- john

Developing by inspection is done by a dark green safelight, as there is a dip in the sensitivity of "Pan" films at that part of the spectrum.

 

T MAx is no more sensitive to red light than other filmns, but may be more sensitive to the green light. A check of teh sensitivity curves for the film will show where the dip is, and thus what colour light can be used.

 

The "safe" light is VERY dim. When I worked in a B&W photofinishing sweatshop the green safelight was barely visible on first entering the darkroom, but after an hour loading film onto the machine, I could read headlines in the papers and read film roll labels by the green light. It takes a long time for the appropriate level of dark acustomising to set in and when this happens and you out into the sunlight, it is like getting hit with a hammer.

Cheers

where did you read this? I have developed by inspection many 400 tmx 8x10 sheets with no problem.

Manufacturers don't exactly recommend developing any film by inspection. For example, from TriX, Plus X data sheets:

 

"Do not use a safelight. Handle unprocessed film in total darkness.

Using a safelight will affect your results. If absolutely necessary, after development is half complete, you can use a safelight equipped with a KODAK 3 Safelight Filter (dark green) with a 15-watt bulb for a few seconds."

 

That being the case, I do note that Ilford Delta 3200 also recommends no safelight whatever (whereas they have a blurb similar to the above for HP5+, Delta 100, etc.)

Actually, the use of a green safelight with panchromatic film is because that is the wavelength the human eye is most sensitive to. So, the extended red sensitivity of TMax is quite irrelevant. Cheers, DJ

This is all very interesting. I, like many others I presume, thought using a safelight would fog modern pan films, and that development by inspection was viable only for the old orthochromatic films. Learn something every day in this forum!

thanks for all your responses!

 

as to where i learned this ...

a photofinisher told me that i was lucky that i did not fog tmax when i developed by

inspection. i mentioned that i have been doing it with tmax, trix and ilford for a few

years now, without a hitch.

 

being confused, i called kodak, and they told me the added red sensitivity ( which he

claimed made the tmax films very different than other films) would cause it to fog

when using the green safelight ...

 

i guess i should just "keep doing what i am doing" and not worry about fogging my

film ( since it hasn't fogged yet!) :)

 

 

-john

"they told me the added red sensitivity ( which he claimed made the tmax films very different than other films) would cause it to fog when using the green safelight" - sounds like a marketing person :D

The Kodak guy was mistaken -the red component of the filterd green safeligh is undetectable. The filter is better than 99% efective for ALL light, even green, and since green removes almost all red, there is none left, or at least not enough to affect the silver.

 

Physics 202

 

Cheers

One of my early lessons was to use the clock (and thermometer)! This applies to both film and prints. You have to become consistent before you can experiment effectively. I can't imagine any advantage to developing film by inspection - the image is faint, even by room light, and easily fogged by a so-called safelight.

 

You should develop a matrix which will give you the exposure and gamma control you need - predictably.

 

The usual mistake is to stop development prematurely, which creates muddy, blotchy results. That may mark you as an amateur or artist, depending on the venue.

i had a feeling the so called kodak "tech-supervisor" was actually a marketing drone,

but wanted to give the benefit of the doubt

 

... i forgot kodak has changed drasticly from the good old days when

there were actually people that knew photography who answered the phone, rather

than people doing a search on a computer database.

 

edward: i have been processing with a timer &c for over 20 years, and find it to be a

little better for me to develop by inspection. i dont' really have a water jacket, so my

developer temperature can go up/down and i would rather know that my negatives

look good or need a little more rather than have film that is either to thin or too

dense.

 

but to each their own :)

 

thanks again for the respnses that reinforced my own thoughts ..

 

john

<i>I can't imagine any advantage to developing film by inspection </i><p>

Here is one, you are doing tests with new film or developer and you are not sure of the time needed to develop.

One more, you overexposed the film and are not sure how much less time to develop.

But the best one is, you can fine tune the development to a point where you get almost perfect negatives all the time if you use a combination of time and inspection. I use the BTZS method and coupled with inspection at the last few minutes I get always the negative I need to print well and easily.