Today, we’re going to take a look at Ilford HP5+ Film, or HP5PLUS. This is a high speed B&W film that comes in 35mm roll, 120 roll, and various sheet sizes. It is a panchromatic black and white negative film with a nominal rating of ISO 400. HP has been around in various versions (HP4, HP3, etc.) for a really long time and is basically the long standing all purpose 400 speed film in Ilford’s lineup similar to how Tri-X is Kodak’s long standing 400 speed film in their lineup.
There are many ways to develop HP5PLUS. If you send your film in here to Simple Film Lab, we develop HP5PLUS with Kodak D-76 mixed at 1:1 for one-shot usage. The development time is 13:00 at 68 degrees Fahrenheit in a Paterson daylight tank with 1 inversion every 15 seconds. We use a 1:4 water:vinegar stop bath between development and fixing. We fix all BW films in Kodak Fixer.
Using Simple Film Lab, here’s the characteristic curve for HP5PLUS:
The scale along the bottom is exposure EVs, the scale along the left is the measured density as seen by the film scanner, meaning raw ADC integer values. The EV 0 mark is an 18% exposure card exposed correctly via an incident light reading via a Sekonic light meter through a T-Stop rated lens. Every dot along the curve is a full stop of light. As a safety measure, I’ve extended the curve by a couple of stops on both sides of the scale to account for variances in development and scanning, though the film, development process, and scanner is generally very consistent.
Exposure Guidance and Dynamic Range/Exposure Latitude
HP5PLUS has excellent dynamic range. You can safely shoot it at ISO 50-400 using the development process described above. The chart above (and the corresponding film scanner profile for Simple Film Lab) has been updated to linearize the toe area of the film in an effort to get a bit more black performance out of the emulsion. The toe of the film is from EV -4 to EV -5 where the film base plus fog starts. As before, by EV -6 we’re well on our way to fully clear film base if not there already with film/scanner noise down to EV -7. On the highlight side, it’s hard to see on the chart above, but there is a very gentle shoulder at EV +5. From there, we have exposed film density samples up to EV +11 with film/scanner noise samples all the way up to EV +13, though the step from EV +10 to EV +11 is only 12 discrete tone values, which isn’t really enough to use without posterization, though you won’t actually use EV +10 to +11 unless you shoot the film at ISO 25 with more than 12 stops of subject brightness range.
For exposure guidance, if developing this film as described above, or if sending it in to be developed by Simple Film Lab, I recommend taking an incident light reading of the darkest part of the scene you want to retain details in and subtracting 2 stops of exposure from that reading. For example, if the darkest part of the scene that you want to retain detail in reads 1/125 shutter, f/4.0 at ISO 400, either set the shutter to 1/500 or close down the aperture to f/8.0, or a combination of the two to reduce the exposure by two stops.
If you don’t have a light meter, then set your camera exposure compensation to +1 stop, and that will generally result in an acceptable exposure for most situations once scanned in and density corrected.
HP5PLUS has reasonably black blacks at ISO 400, though if you want really black blacks, it’d be better to shoot it at ISO 250-320 or even 200 (the equivalent of +1 exposure compensation). If more development time is given, it can probably be pushed pretty easily to a solid ISO 800-1600, but at the expense of ISO 50-100 and a different linear reference curve, which means a different film profile if processed and scanned in here at Simple Film Lab. You can shoot it at ISO 800 with no other changes, but that will result in the film fog moving up by one stop so your blacks will be more like really dark gray.
HP5PLUS has good resolution for a 400 speed film. Ilford’s spec sheet doesn’t quote spatial resolution or have an MTF chart, however, with that being said, it looks a lot like Kodak 400TX. It’s not exactly the same, but I’d probably confuse the two if I didn’t know which was which when looking a sequence of images shot on both films back-to-back.
In terms of grain, again, it looks a lot like 400TX. HP5PLUS is in many respects totally interchangeable with 400TX as a film and if they’re both shot and developed exactly the same are said to be nearly indistinguishable from each other. I’ve not yet done that comparison, however, from what I’ve seen of the two films that I’ve shot thus far, that appears to be a fair assessment.
Here’s a link to a Flickr Album of more images shot on Ilford HP5+. I’ll add more images as I have them available.