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 - read on to find our more!
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.
WHY SHOOT IT?
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 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 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!
HOW TO SHOOT IT?
The most important things to remember with shooting Reversal films are:
Reduced Latitude - typically Reversal films have reduced dynamic range between 5-7 stops! That's a huge difference to the 10-14 stops of negative films! There's also less room for error in highlights, perhaps +/- half a stop and if highlights are overexposed they are irrecoverable!
Metering and Scene Contrast - WHAT you shoot matters with Reversal. A high contrast sunny day will have more dynamic range than the film can handle, so metering intentionally is critical. A Spot Meter is going to be your best friend ensuring that the areas of your scene you want to be adequately exposed are within your films possible dynamic range - contrast ratios are a real help here!
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 them 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. We are the only UK lab to offer B&W reversal processing (at time of writing) 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 and have some drawbacks like overly soft emulsions after processing (in our experience). Even with a kit, 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 (though slightly tweaked by us) 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 - but don't go crazy!
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!
Final Rinse - This again is a standard B&W final rinse process using something like Photo Flo!
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 typically 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 employ, is to scan the film as B&W Negative - 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 - a lot of the fulfilment is about the journey not just the destination!
Happy Shooting!
Nick - Poly Film Labs Team