steven7

In simple terms, ISO (international standards organization) comes up with standardized ways of measuring everything. Measuring contrast of an image is something they've standardized, look up "ISO contrast". Then "ISO speed" defines the amount of light you need to achieve the ISO contrast (film or digital).

Exposure index is simply whatever your camera is set to. You can give your film less light but develop longer (pushing). Delta 3200 is a misleading name, you should interpret it as "ISO 1000 film optimized for pushing to 3200". BTW you can "push" digitally too: you'll end up with a darker RAW file, but move "exposure" slider to the right (effectively multiplying all recorded values by some factor) and you'll end up with a brighter image but more contrast (because of the reduced range of useful values)

Where does this utter nonsense come from?

Not from any authoritative source, nor from anyone with experience.

 

I've been processing film, both professionally and as an enthusiast since I was 10. I'm now over 70, and for most of those 60 years I've used no more than two inversion agitation cycles per minute with B&W film, and no pre-bath. In all that time I've never noticed a lack of development in the highlights, nor had any complaints about the quality of negatives produced.

 

Lack of highlight density is produced by using a too dilute or too cold developer, or too short a time. The amount of agitation is generally grossly overrated in the effect it has on the degree of development. The main purpose of agitation is to prevent streaming and 'Mackie lines', not to control density. If you aren't getting streamers, patchy development or edge-effects, then your agitation technique is more than adequate.

I am 40 and I've been processing film since last February. Having developed only about 30 rolls I can clearly see that frequency of agitation has very similar effect (to image contrast) than the development time. In fact, one doesn't need 40 years to notice that. Just 1 hour and 2 rolls is enough to follow Kodak-recommended agitation (every 30 seconds) and Ilford's (every minute) to see the difference. That difference is clearly visible in their data sheets too, i.e. Kodak's development times are usually shorter for the same developer+film combination.

Perhaps your point was that people exaggerate the importance of agitation, and maybe that's true, but it reads almost as agitation hardly matters. Apologies if I misunderstood.

Two observations:

• Most films of "my favorite" variety are discontinued. Is that because they're truly great, or because they're gone and it sucks? If they were awesome, why they disappeared and others remained? I can't tell because I just recently got back into B&W and haven't used any of the older emulsions.
  
• Tri-X is consistently described as "grainy" and "gritty". I suspect it used to be like that prior to 2006 reformulation. But Tri-X I get from B&H is finer grained than all Ilford/Ketmere ISO400 films, including Delta 400, which is always described by everyone as "fine t-grain" emulsion. Feels like film descriptions are being copy-pasted from the 90s, or perhaps people are using frozen old stock?
  

I just discovered this retailer:

"Photo Warehouse (UltraFineOnLine)

121 Lombard Street

Oxnard, CA 93030"

They have their own film, and even their own chemicals. Obviously, they don't manufacture any of it. Does anyone have experience with this brand? I've googled and searched on this form, and people in the past suggested that it's a rebranded Ilford's Delta series.

If true, that's incredible. Delta (to me) is a "Cadillac/Mersedes of B&W films" and here I can get it for $50 per 100ft roll. Is there a catch? Their chemicals are affordable too.