B&W REVERSAL: In Depth
WHAT: B&W ‘Reversal’ otherwise known as ‘Slide’ or ‘Positive’ film.
AVAILABLE FORMATS: 35mm, 16mm, Super 8, Double 8, Double Super 8.
SPECIFIC BRANDS / PRODUCTS: Kodak Tri-X, Foma R100, Adox Scala
IN DEPTH METERS:
Film Cost Meter: £ £ £ (3/5)
Processing Cost Meter: £ £ £ £ £ (5/5)
Shooting Difficulty Meter: 📸 📸 📸 📸 (4/5)
Processing Difficulty: 🧪 🧪 🧪 🧪 🧪 (5/5)
WHAT IS IT?
B&W ‘Reversal’, also known as ‘Slide’ or ‘Positive’, is a B&W film that basically shows a real image at the end of processing as opposed to more typical B&W ‘Negative’ film that shows a negative image at the end of processing.
This is accomplished by the ‘reversal’ processing method which flips the initial negative latent image captured by the camera into a positive image through a bunch of additional steps and chemical baths (vs normal B&W Negative processing).
WHY SHOOT IT?
B&W Reversal is a beautiful format - in fact we have a bit of a soft spot for both B&W and Colour Reversal films as there’s just something magical about seeing a true positive image on your film post-processing.
It’s a feeling that can’t really be described - it is just magical.
That aside, it does have a specific look due to it’s reduced dynamic range and high contrast and this can be something of a draw if you are after that look - though this does vary also by film stock.
It also requires quite a bit of thought and care on scene/subject selection with that in mind as well as a not insignificant bit of light metering mastery to get an adequate exposure. That makes it a challenge, and challenging oneself is reason enough to give this format a try!
WHICH FILMS ARE AVAILABLE?
Here’s the thing - any B&W film can be reversal processed. BUT some films are more suited than others particularly those that have a clear film base as opposed to those that have a tinted base (like the purple found in some B&W negative films).
We’ve used a ton of different ‘standard’ B&W negative films such as Foma 100, Foma 400, Kentmere and other Ilford and Kodak film offerings succesfully but some definitely do hold up better than others and some just look better than others due to suiting the reversal process better - it’s a bit of a discovery process.
That said, there are specific films targeted to the B&W Reversal process most notably Foma R100, Adox Scala and Kodak Tri-X - these also have a silver-based anti-halation layer so they really can ONLY be reversal processed, not doing so would basically make the un-scannable / un-printable.
B&W REVERSAL PROCESSING
One of the complexities / constraints when shooting B&W Reversal is both how and where to get it processed. Only a handful of labs in the UK (like us!) offer B&W reversal processing for either Photographic or Motion Picture films as it’s both a complex and long process (time-wise) typically meaning higher cost.
Chemistry kits are available such as the Foma and Bellini B&W Reversal kits, but these are only suited to those who process films themselves to begin with. Even then, it’s a different experience than B&W Negative!
If in doubt, check us out - as we are the only lab processing both Photographic and Motion Picture films in the B&W Reversal process on the regular in the UK (though these are ALL hand processed !).
The B&W Reversal process itself involves 7 steps vs the 4-step B&W Negative process. We follow the ‘Ilford’ method as for us it’s been the most flexible and consistent process across Photo/Motion Picture.
The general steps of the process are:
1st Developer - typically a High Contrast development and the most significant determinant of the final result. This step is all about ‘baking in’ the final image. A longer development time here will create a brighter end-image and less development a darker one.
Bleach - This is an aggressive bleach that dissolves the metallic silver created from the 1st Development, as well as for some films removes the silver-based anti-halation layer (a must!). This is a mix of sulphuric acid and either Potassium Permanganate or Potassium Dichromate (the former being less toxic, but neither are exactly great for you - handle with extreme care!)
Clarifier - This is a Sodium/Potassium Metabisulphite bath that removes the purple / brown staining that comes from the Bleach (the Bleach is purple and as it oxidises it turns brown!)
Re-Exposure / Reversal - This step is all about fully exposing the residual silver halide left after the 1st Development / Bleach that removed the ‘original’ image. This is what creates the ‘positive’ image as the original exposure in the camera captured a negative image, so by developing and then removing it, we’re left with the inverse (negative) of the original negative…thus a positive 😵💫
We find it easier to think of it just like math, a negative times a negative equals a positive!
The re-exposure can be done using a Stannous Chloride (Tin (II) Chloride) based bath or manually re-exposing the film. Most people do the latter as reversal baths are notoriously short lived and quite dangerous in a dark room - any spillages / contaminations have the effect of exposing your un-exposed / un-developed films so yeah…caution advised!
If manually re-exposing, tungsten light is the best light in order to combat a phenomenon called ‘Solarisation’ which basically happens with ‘blue’ light and causes exposed areas to invert themselves…making them turn back into a negative 🤯!
Physics huh, it’s insane.2nd Development - This is a ‘standard’ black and white development and is aimed at fully developing all the residual silver halide exposed in the prior step. The thing to remember here is that the original exposure and 1st development ‘baked in’ the final image’s contrast, gradations, bright areas and dark areas etc so you can’t really over develop it!
Fixer - This is a standard B&W negative fixer process - we skip the ‘stop bath’ as we don’t need it as in the 2nd development we are developing all silver halide to completion so no need to stop it!
That said…it is highly (HIGHLY!) recommended that the fixer used has a hardener in it. That’s because the Sulphuric Acid / Potassium Permangenate process seriously softens the emulsion and if a hardener is not used a phenomenon called ‘Emulsion Lift’ can happen which literally ‘lifts’ the emulsion off the film base… so bye bye emulsion.
These fixers are hard to find these days as emulsions are pre-hardened (but trust us, you need some additional hardening), so adding some Chrome Alum (again, a toxic substance) based hardening step can be done in place of a hardening fixer.
Up until recently, Kodak Powder Fixer was readily available and a great hardening fixer - grab it if you find it as it’s by far the most cost effective and easiest solution! Another fixer that can be used is the TMAX Fixer, though it’s not as good as the Kodak Powder Fixer as a hardener; extended fix times have worked best for us when using this.Final Rinse - This again is a standard B&W final rinse process using something like Photo Flo!
HOWEVER - we always test the emulsion softness after the Fixer / Hardener with a finger nail - if the emulsion is easily removed then it’s recommended to allow the film to fully dry before doing the final rinse step - we’ve typically lost emulsions either in the 2nd development (before the hardening fixer) or at the final rinse stage - the wetting agent somehow accelerating some emulsion lift.NOTE: This is all trial and error advice here - choose to follow or not follow as you see fit!
B&W REVERSAL SCANNING
Here’s the other challenge, not every film lab scanner can deal with B&W Reversal/Positive films. That’s because scanners either expect B&W film to be Negative and only expect ‘Positive’ film to be colour. The latter causes a problem as the scanner isn’t expecting silver when scanning colour reversal, it’s expecting just the dyes so it leads to whacky results.
Whilst we don’t have experience with the Frontier or Noritsu scanners, what we can say is that the Konica R1 scanners cannot deal with it but the Pakon scanners can deal with it, when scanning as 'POS’ using the TLXClientDemo scripts.
One option, that other labs may employe, is to scan the film as B&W Negative - this will actually create a negative image as the scanner expects to be scanning a negative image and thus inverts it after scanning - as ours is a reversal image this flipping nature turns it into a negative - again a headache 😵💫
If using the B&W Negative scan options, just expect to have to invert the image after the scan is finished.
WHERE TO NEXT?
If you are looking to save some money, our honest opinion is just to grab some cheap Foma 100/400, shoot it as normal and then send it off to be reversal processed - this will save you a few £’s on your first test roll.
If you want to try it with specific reversal film, our favourite is Foma R100.
For Motion Picture shooters - Kodak Tri-X is our favourite but again Foma R100 is a great affordable option particularly if your shooting the Double8/DoubleSuper8 formats.
Whatever you choose, just remember to keep an open mind, expect some learning (failures) and see it as a refinement of your craft - alot of the fulfillment is about the journey not just the destination!
Happy Shooting!
Nick - Poly Film Labs Team