Ilford SP 816

[slow]

I see an Ilford SP 816 by my dealer he told me this is the film like

ilford sfx I dont know I dont see for now any pictures taken with

this type of film.

[hans_beckert]

It was easy to do this, just go to their web site. That's the best place to start on such questions.

 

See:

 

http://www.ilford.com/html/us_english/bw.html

 

TRAFFIC SURVEILLANCE (SP816T)

[david_goldfarb]

I looked into this once, and indeed, SFX seems to be SP 816 in conventional 35mm cartridges. SP816 has extended red sensitivity, because red filters and red filtered flash are used for traffic surveillance, and it happens to be interesting for creative effects. I haven't tried it.

[roger_hicks1]

From memory there are both SP815 and SP816 -- one on conventional base, substantially identical to SFX, the other on ultra-thin polyester base (MUCH thinner than conventional) which can lead to problems in conventional cassettes. Unfortunately I can't remember which is which. I raise the point only to warn you. I've had excellent results from this emulsion in all forms (815, 816, SFX).

 

Maco's excellent Cube 400c (coated in Croatia) is another extended-red film derived from a traffic surveillance product.

[hans_beckert]

This does not appear to be identical to SFX, as the ISO of the latter is 200, that of the former 400.

[roger_hicks1]

Dear Hans,

 

Sorry for the delay in replying: I have been away. As I thought, the emulsions on SP815/816 and SFX are identical. The different speeds are the results of different developer (and development) recommendations. I have just confirmed this with Ilford.

 

Cheers,

 

Roger

[hans_beckert]

Interesting that they specify two different speeds, then, no?

[roger_hicks1]

Dear Hans,

 

Interesting indeed, but not too surprising. ISO speeds do vary with developers, after all. My suspicion is as follows:

 

SP815/816 is probably ISO 400 (or at least 320) in DD-X with continuous agitation; enough to sell it as 400 given that it is normally pushed in speed cameras -- apparently they give instructions for all sorts of pushes, because after all, pictorial quality is not where it's at with speed cameras.

 

In a more conventional developer such as ID-11 it may only be 250, and as this is a 'funny' speed, they round down to 200 -- or use Perceptol as their speed determining developer. Over-exposure will increase grain and decrease sharpness but may well give superior tonality.

 

I don't have any SFX to hand at the moment but I wonder if it has an EI or an ISO speed marked on the box. There are several examples of the former, after all: TMZ, Delta 3200, Fuji Neopan 1600.

 

Cheers,

 

Roger

[gary_ferguson1]

Ilford SFX is branded "Ilford SFX 200" and described on the reverse of the box as "EI 200/24".

[roger_hicks1]

Dear Gary,

 

EI, eh? Thanks!

 

Cheers,

 

Roger