Hello again, and some Kodak b/w questions!

[Guest]

Hello everyone!

I've returned from my winter hybernation and as always when the long evenings and sunny days start here in the U.K. I've dusted off my super8 gear and have got back into the filmaking mood!

I intend to shoot some Tri-X and Plus-X this Summer but have some questions about the ASA ratings of these films. Can anyone tell me what speed Tri-X and Plus-X films are notched for and which film speed the camera will auotmatically set them at?
I have a Nizo 156 macro and it says in the book that the speeds for B/W film are 40 and 160 ASA, I'm assuming the higher figure is the one where you would have the 85 filter removed and the lower figure with the filter in place.
Now, taking Tri-X as the example would my camera assume this film was 160 ASA from the cartridge notches and therefore expose it as this speed with the filter out of place? If this is the case then am I right in assuming that the film (rated at 200t) will be overexposed by 1/3 of a stop?

Now I've just throughly confused myself by looking at the Kodak super8 site where Tri-X is rated at 200D and 160T. I guess I need to know which film speed Tri-X is notched for before making anymore assumptions!

Help! :roll:

[Technicolor]

Gahhhhh! Its so annoying when that happens!

sorry everyone that was me! :oops:

[T-Scan]

Plus X in now 100ASA, TriX 200ASA.

[monobath]

Plus X in now 100ASA, TriX 200ASA.

To be more precise, Plus-X is 100 ASA daylight, 80 tungsten IF you develop it in D-94A. If you develop it in D-94, it is 50 daylight, 40 tungsten. I don't know how other developers affect speed.

I haven't bought any of the new Plus-X 7265. Is the cartridge notched differently from the older 7276 cart?

[Actor]

I intend to shoot some Tri-X and Plus-X this Summer but have some questions about the ASA ratings of these films. Can anyone tell me what speed Tri-X and Plus-X films are notched for and which film speed the camera will auotmatically set them at?

Good question! Tri-x is 160T/200D. I think it is notched for 160T.

Before Kodak changed the formula Plus-X was 40T/50D and notched for 40T. Now it is 80T/100D. Since the standard does not specify notiching for 80T I don't know what Kodak is notching it as today. Examine the cart. You can find the notching specs here:

http://lavender.fortunecity.com/lavende ... ching.html

I have a Nizo 156 macro and it says in the book that the speeds for B/W film are 40 and 160 ASA, I'm assuming the higher figure is the one where you would have the 85 filter removed and the lower figure with the filter in place.

No. The lower figure is for the now defunct Plus-X formula and the higher one is for Tri-X. All figures are for the filter switched out, even under daylight.

Now, taking Tri-X as the example would my camera assume this film was 160 ASA from the cartridge notches and therefore expose it as this speed with the filter out of place? If this is the case then am I right in assuming that the film (rated at 200t) will be overexposed by 1/3 of a stop?

Yes. Shooting under daylight with the filter switched out you will overexpose your film by 1/3 stop. I think switching the filter in might remedy this but I'm not sure.

Take what I'm saying with a grain of salt. It's been a while since I shot any B&W and Kodak has changed the formula for Plus-X since. I could be wrong but I don't think so.

[wahiba]

I used 100asa and 200asa on my manual Quartz and processed it negative using basic ID11 developer and it came out fine, if a bit grainy. It might be different if reversing.

[Technicolor]

Thanks for the help Guys,

Actor, the Plus-X I've ordered is in the old style box which I'm assuming is the older, so will it be exposed at 40ASA with the filter removed? What happends then when I want to shoot in daylight, do I engage the filter and what happens to the film speed if I do?

I guess the only thing to do really is to wait until i get the carts and try it?

[christoph]

ok there seems to be a lot of confusion about the new b/w films, so i'll try to clarify:

the higher EI rating of plus-x is not really a result of the film, but rather of the processing.. the old plus-x will be one stop faster as well if processed by the new chemicals..

with tri-x nothing really changed.. except that the grain should be slightly smaller.

the other thing is that the b/w films are 1/3 stop slower under tungsten light.. that has nothing to do with filters but rather that the emulsion is more sensitiv to blue light than to red light.. and daylight is just bluer ;)

so here is an updated table of some of the variables:
(view in a fixed width font):

Code: Select all

EI = exposure index
D = daylight (5500K)
T = tungsten light (3200K)

7276 = old plus-x
7265 = new plus-x
7278 = old tri-x
7266 = new tri-x
D-94 = old first developer
D-94A = new first developer


EI                     |  7276  |  7265  |  7278  |  7266  |
-----------------------+--------+--------+--------+--------|
D w/o filter in D-94   |  50asa |  50asa | 200asa | 200asa |
D with filter in D-94  |  32asa |  32asa | 125asa | 125asa | 
D w/o filter in D-94A  | 100asa | 100asa | 200asa | 200asa |
D with filter in D-94A |  64asa |  64asa | 125asa | 125asa | 
-----------------------+--------+--------+--------+--------|      
T w/o filter in D-94   |  40asa |  40asa | 160asa | 160asa |
T with filter in D-94  |  25asa |  25asa | 100asa | 100asa |   
T w/o filter in D-94A  |  80asa |  80asa | 160asa | 160asa |
T with filter in D-94A |  50asa |  50asa | 100asa | 100asa |   
-----------------------------------------------------------+

++ christoph ++