2018 is going to be a great year!
We’ve updated or are in the process of updating the pages for Simple Film Lab and the new updated order form should be online and available within the next couple of days.
Here are the highlights:
We’ve introduced a new standardized film development regime based on XTOL and standardized our scanning protocol so that film you send in to us can easily be either printed onto photo sensitive paper in a darkroom, or can be scanned in using standard contrast indexes that correlate to black and white paper grades. This makes things much simpler and leads to other things listed below.
All Black and White Negative Films
We can now develop and scan in all commonly available black and white negative films in 135, 120, and 4×5 sheet formats, so send them in and get them processed! This is huge for us and we couldn’t have been able to realistically do it without standardizing our development environment.
Custom Film Development
Yep, we do that too. In addition to XTOL, you can request that your film be developed with D76, HC110, and Rodinal with custom dilutions, development temperatures, development agitation scheme, and development times. You can pretty much go nuts, though be aware that doing so can lead to unpredictable results.
Custom Film Scanning
Want your film scanned in with the equivalent of a grade 3 paper instead of the standard grade 2? No problem. We have a range of available contrast indexes that you can have your film scanned in at. It’s the digital equivalent of printing on said paper in the darkroom except you get a Digital Negative file instead. Combined with custom film development and you can get really creative if you want to.
Other File Formats
Don’t like Digital Negatives? No Problem. You can now request other formats without actually going the custom scan route.
There’s more than this, so check the Lab pages as we’ll be getting those pages updated with whats going on for 2018!
Spending some time with Google shows that there are numerous comparisons between Kodak Tri-X (400TX) and Ilford’s HP5+ film. Are they the same? Are they different? Is one better than the other? On and On and On. Let’s take as objective look as possible between the two emulsions and see what the deal is here.
Cut to the chase
If you don’t want to read any further, and just want a fast answer, then here it is: Kodak Tri-X and Ilford HP5+ are so close to each other that I can say that they are totally, completely, one hundred percent interchangeable. This means that you can shoot and process them exactly the same way in the same chemicals for the same development time. The end result will be close enough that you can’t tell the difference.
We are going to evaluate the two emulsions on two criteria: Tonal range, and granularity.
To evaluate the tonal range, we’ll shoot an 18% grey card on each emulsion, and shoot it from 7 stops under to 11 stops over normal exposure in full stop increments with a studio strobe. The exposure will be set via a Sekonic light meter incident reading and shot through a T-Stop rated lens, with the light meter reading within 0.1 stops of the actual amount of light hitting the grey card. To evaluate the density values for each stop of light, the emulsion will then be digitized with a DSLR using a studio strobe through the same T-Stop rated lens.
From there, the raw captures are evaluated and the average sample value from a 256×256 square in the middle of the scanned frame is calculated. This is done for each emulsion. This will give us a good idea of the density level of the emulsion for a given exposure value.
This is done exactly the same way for each emulsion. The camera position relative to the gray card does not change between each emulsion, and the focal point does not change between each emulsion.
For granularity, this is actually pretty straight forward. Look at the scan of the correctly exposed 18% grey card for each emulsion in Adobe Lightroom at 1:1. The scans are just over 4200 dots per inch, which is more than enough resolution to actually digitize individual grains.
To ensure that we’re as close as possible for each emulsion, they’re both developed in Kodak D76 1:1 at 20 degrees Celsius +-0.1 degree in the same daylight tank at the same time for 13:00 with 1 fast inversion every 15 seconds. There was a several minute pre-soak at 20 degrees of the tank/emulsions to get everything up to temperature. A 1:4 vinegar/water stop bath was used to stop development. Both emulsions were fixed in Kodak Fixer for 10:00 with constant agitation.
Obviously, this is not up to scientific standards, however, it is within the tolerances that I can bring to bear with the equipment available to me, and I feel that my tolerances are tight enough to use with a reasonable amount of certainty in the results.
Below are the results for each item being evaluated.
Here is the chart of the two emulsions.
When looking at this, there’s a couple of things to remember: It’s not the actual values of each density step that matter because those will vary a bit due to variations in the the power of the strobe firing during the exposures, variations of power of the strobe firing during the scanning, and how many specks of dust and fibers there are on the emulsion in the scanned sample area, which will affect the average calculated sample value. In fact, I’ve repeated this test twice exactly the same way and have even done multiple scanning passes of each emulsion for each test and gotten different but similar results for every single density step. This is the nature of the medium. There’s a lot of moving parts and things that can affect the outcome.
The key takeaway here is the shape of the curve for each emulsion. I’ve included a combined curve that is the average of all the scanning passes of both tests for both emulsions with each end slightly extended beyond sampled values.
In short, both emulsions have the same tone curve and tonal range if developed in the same developer at the same temperature, for the same amount of time and same agitation.
OK, what about the grain? I’ll let the image below speak for itself. You can right click on it and download the full image to look at it at full size if you want to look at it really close.
So, what are we looking at? A comparison of each emulsion scanned in at 4200+ dpi side by side at 1:1 in Adobe Lightroom. The grain structure is readily evident, and frankly, to me, the two emulsions are close enough in their granularity that at sane enlargement levels, they’re nearly if not completely indistinguishable.
With black and white film, the tonal range and granularity are really only the two things that matter, and as I said in the cut to the chase section, if Tri-X and HP5+ are shot and developed the same way, they’re interchangeable in terms of tonal range and granularity.
“I shot it at 1600 and pushed it 2 stops! It looks great!”
I’m sure we’ve all heard this. It’s largely a myth. All films are within a third of a stop of the manufacturer’s published ISO rating in most developers.
This is extremely true of C-41 color films because the processing is standardized and the films are manufactured to conform to that processing environment. Given that, we’re not going to talk about color films. If it’s rated for ISO 100, shoot it at 100. If it’s a 400 speed film, shoot it at 400. Any lab that is worth anything can give you a wonderful scan of that film.
For black and white films, this is also largely true based on how the ISO standard prescribes determining the speed of the film which is explained very simply:
Film speeds are based on the exposure required to give a log density of 0.10 above film base plus fog (fb+f).
Keeping it simple
Terminology aside, we can say the speed of the film is determined by the amount of exposure needed to get a certain fixed amount of density above film base plus fog. For the ISO standard, that fixed density is 0.10 log density above film base plus fog. You can use a different fixed density level and you can use a different density scale and that’s totally valid except that it’s not to the ISO standard.
Where the confusion comes in is film density in the shadows or minimum density areas of the emulsion develops at different rates depending on the film developer used. The developer used along with developer temperature and time spent developing affects how much density is developed.
Push that film!
Not so fast. You see, depending on the size of the silver grains in the emulsion, you do in fact need a minimum amount of light to hit each grain so that it will develop anything at all. Believe it or not, that minimum amount of light is amazingly close to the ISO rating of the film.
So what does push processing actually do?
Simply put, push processing develops more density for the silver crystals that did get enough light to develop anything. What this does is make the density difference large enough that you can see it and gives the impression that the film is more sensitive than it actually is. In Adobe Lightroom speak, it’s the equivalent of going into the Develop Module and pulling the shadows up without changing the black level.
It does not make the film more sensitive. Once you go below that minimum exposure level, no amount of processing is going to bring more density into the emulsion. All you’ll do is develop more film fog.
So how come some films still look great pushed?
That’s because normally exposed and developed film typically has its film base plus fog at 6 stops below middle grey. That makes for some awesome blacks. If you switched over to the Exposure Index method of exposing, and under exposed the film by a stop, the film base plus fog effectively moves up by one stop to 5 stops below middle grey. This still results in totally acceptable blacks for most exposures. If you under expose by 2 stops (exposing a 400 speed film at EI 1600) the film base plus fog moves up to 4 stops below middle grey. This results in your blacks starting to look dark grey and a little muddy. This is where the push processing come in. More development time adds more density to what shadows you do have which makes the shadow areas have more contrast which to a degree counteracts the raised film base plus fog. There is a point of diminishing returns because once again, there is a minimum amount of light you need in order to develop anything above film base plus fog.
So that’s it in a nutshell. Pushing film is a myth. If you switch to a different exposure standard (like Exposure Index), then you can get a little more performance out of your film, but at the end of the day, the worst thing you can do is under expose your film.
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.
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