After numerous mess-ups with Ilford HP5, I finally got to test it a little more accurately.
I used Ansel Adams film testing method and modified it with a side note he made to make it easier. It is worth reading Ansel Adam’s “The Negative” to get a better understanding of the Zone system. I found it takes me so damn long to work out the exposure time, especially as my Pentax spot meter measures in 1/3stops, but my cameras are all 1/2 stops, that I had to tweak it.
The test ensures that the film turns out rated at what the box ISO says it should be. To new users that might seem absurd but your development technique may be different to Kodaks, or your thermometer is a little shit, your cameras shutters a bit lazy or the film company slightly lied (common). The test also ensures the development time claimed is also correct, this is even more variable and out of the film/developer manufacturers’ hands due to the massive number of variables from your water supply, development tank, agitation methods etc.
The order of procedures in the Adams printed method would require you to make 9 exposure calculations, always dealing with that 1/3 stop issue if you have the Pentax spot meter. Simplifying it means you only need 3 calculations and eliminate the 1/3 stop issue. The results are the same.
To simplify the test, I mess around with the placement of my Lastolite grey reflector so it always reads as a whole stop readout on my spot meter. If it was 1/3 or 2/3rds of a stop, my GCSE maths knowledge causes my frustration levels to increase exponentially. I assumed HP5 is more likely to be rated at a lower ISO than higher. I started with an assumption of Iso200.
It is better to change your exposure via the lens’s aperture. Keep a sensible shutter speed, avoiding extremes. Shutter speeds are not always super accurate. Using both sides of the Grey/white reflector, it’s possible to keep your exposures within normal levels. The reflector/card/board doesn’t have to be a perfect 18% grey for this test and alternating between grey/white does not affect the result.
For the image I assumed at ISO200, I placed the reflector so it would appear on Zone 1 and took a photograph of it. Placing a subject at Zone 1 means it will be captured on film with the lowest useful density noticeable above the clear base of the polyester film. I then closed down the aperture by ½ stop and fired off another shot. I then closed down another ½ stop and took a third shot which would end up ISO 400. These 3 images shot at Zone 1 help establish the minimum exposure time needed to give a useful amount of density on the film.
I repeated the above but placed the reflector on Zone 5, taking the 3 varied exposure shots, and then Zone 8, taking the final 3 shots. Placing a subject on Zone 8 means it will be captured on film with a very high density. Zone 8 is considered the highest amount of density film can capture without losing the detailed textures of the subject. A white building in sunlight would be a good example where you want the texture of the stone to show. It is more accurate to test a Zone 8 exposure than a Zone 9-10 with a densitometer.
The Zone 5 and Zone 8 exposures test for the development time, typically it’s the time in the developer that builds density whilst the shadows are far less affected by too short or long development time. Shadows are almost fully controlled by exposure provided you don’t do some seriously off-the-chart development. Incidentally, I’m not sure if the Zone 5 step is even needed other than it adds an extra level of data, perhaps for more nerdy levels of Zone system manipulation.
The result from my densitometer shows that Ilford HP5Plus 120 with Bellini Euro developer (HC110 Copy) is a solid Iso 400. Base fog is clearer than the 35mm film at around 0.13 whatsits. If shot at Iso 400 the Zone 1 shadows have the perfect density readout of 0.1 whatsits above base fog. However, the Zone 5 and Zones 8 indicate that my 6 mins 30secs development time is too short. Enough to be visibly noticeable to the naked eye rather than a £400 niche densitometer only an obsessed loon would buy, like me.
One discovery I did make is that over exposing and under developing; may not work. Modern films have quite a lot of latitude which is a blessing and a curse. A blessing in that less than ideal processing can give good results. A curse because trying to push or pull development times will be ignored by the film. I did notice that even when shot at ISO 200, the Zone 8 exposure still isn't as dense as it should be. Iso200, 320 and 400 shots all gave exactly the same desnity to Zone 8. This could indicate a fair amount extra time in the developer is needed to force its density higher. Ive a niggling feeling that HP5s lattitude errs on being a little under developed.
It is worth noting that as I had previous agitation issues with 120 films, I now agitate very gently without completely inverting the tank. It appears agitation could have a considerable effect on development time. With very Gentle agitation it may require 20-30% more time. For note, my process is to gently agitate the development tank for the first 30 seconds, and then 4 gently swirls every 30 seconds after right upto the last seconds.
With the current cost of film, instead of firing off another roll of film to perfect the development time, I will try to take one shot of a grey surface at zone 8 on every roll of film and monitor the results with tweaked development times. For my purposes, I only need good enough and within another 2 rolls, I should be perfect. Hopefully, this marks the end of my ‘meh’ relationship with Ilford HP5.
I know many people offline who hate Iford HP5, they say its dead of contrast and lacks any character. In contrast (excuse the pun), the film is highly regarded by almost everything I read online. I’ve no certain explanation. Personally, I find it has a wide latitude that tends to throw everything into a low contrast zone, and to counter that you just need a fair bit more development to begin to kick it out of its comfortable low contrast nature. Others might just be lucky sods, or talented sods or perhaps more common, people who think it’s perfect but don’t have a densitometer to realize they’ve been developing it a bit under for the last 30 years whilst all the time appearing like a photrio.com film-forum guru. Perhaps I just keep fucking something up and it’s a great film. Anyway, I’m 82% certain my next roll of HP5 will be sweet, and that’s all that matters.
