Plus-X in 40/160 cams

[Splee]

I'd like to shoot some Plus-X in my Canon AF310XL. I've successfully shot Tri-X with it already, where it exposes at 160 with no problems. I switch the filter out for this. With the filter switched in - it's manual, so no problems here - it rates films at 100, so I assume this makes it suitable for Plus-X. Any problems/pitfalls with this before I rush out and buy some?

Lee

[jpolzfuss]

I'd like to shoot some Plus-X in my Canon AF310XL. I've successfully shot Tri-X with it already, where it exposes at 160 with no problems. I switch the filter out for this. With the filter switched in - it's manual, so no problems here - it rates films at 100, so I assume this makes it suitable for Plus-X. Any problems/pitfalls with this before I rush out and buy some?

Lee

AFAIK all Kodak b&w stock are daylight ones - so you'll never use the tungsten-film wratten-filter?!

[Splee]

Yes, I know you don't need to use the filter as far as colour temp etc. is concerned - on my camera, the filter can be switched in as required, and I want to know if it can be used to make the camera expose the film correctly.

[jpolzfuss]

on my camera, the filter can be switched in

AFAIK the b&w-films tell the camera that the filter "is useless". Hence 99% of all cameras won't use the filter even if you tell them to do so!

[Splee]

Yes, but my camera WILL use the filter. The filter notch on the cartridge does nothing on the AF310XL, so back to my original question...with the filter in place, will this expose correctly?

Lee

[super8man]

The camera will think it is 160 asa without the filter in place is my best guess. I have the sound version of your camera and there is no feeler of any kind for the presence of a cartridge filter notch. Therefore, the upper button will be in the OUT position and therefore the camera will think it has a non-k40 cart in place. Hence the 160asa rating of the meter. If this is so, then an underexposure of 100 asa plus x may not be desirable...you can compensate in development though if you do it yourself.

Hope this helps. I have not tried this so be warned.

mike

[monobath]

If you want to expose Plus-X at 100 ASA, I'd suggest that you leave the filter switch on the camera out, and either add a 0.2 ND filter on the lens, or a #3 or #6 (K1) light yellow filter. The filter factor for the #3 is 1.5, for the #6 is 1.6, either one effectively 2/3rd stops. The slight yellow filtration will help to reduce haze a bit, too.

Kodak Filter Information for Cine Films

See if that link helps.

[super8man]

Yu can't - the camera is TTL - not like the early 310XL camera...

[monobath]

Well, shucks!

[xeno_basso]

For cameras that have the little prong inside below the gate I do what Martin B suggests and break a small piece off the cart (if you need to know where just compare it to a K40 one) so that the filter will be left in place. Tri-X Film has better contrast (is that right term?) when exposed with the filter. Its like shooting B/W 35mm film. Without a filter everything goes white...unless of course you are using it in really low light situations.

My understanding is that the film speed is 200. I believe that auto cameras will set the film to 160 but with the filter in place this comes to something like 125 which is about a third of an f/stop.
Without the filter, the film will be exposed as 160 but this is again a third of an f/stop but in the other direction.

My experience is that this 1/3rd over or under is OK but I understand purists out there will want to have it spot on. believe I tried to travel this road too but gave up, settling on the fact that its either 1/3 over or under.

Check out:
http://lavender.fortunecity.com/lavende ... lters.html
where I had the original discussion with Martin all those years ago

john