Ask us about our favorite black and white films and you won’t have to listen long before we bring up the Rollei RPX films. Here at the shop we have developed a growing appreciation for this family of films. But honestly, most of our attention is centered around RPX 100 and RPX 400, meanwhile we don’t venture down to RPX 25 nearly often enough. Thus we figured we would rectify that a bit by giving this ultra-low ISO member of the RPX family its Film Friday due.

To classify RPX 25 as a member of the RPX family is bit misleading. If 25, 100 and 400 are really siblings, RPX 25 is more of a step-brother than it is a biological brother to the faster two films. This is mainly due to it having a look and feel that is more different than similar to these films. But before we get into that aspect of RPX 25, let’s talk a bit about this emulsion’s history and origins.

Rollei RPX 25 was introduced to the market around 2014 by Maco Direct. Maco is a German distributor that, among other things, has a license to use the Rollei name on a line of films. Maco doesn’t manufacture any films on their own, instead contracting that to other European film manufacturers through a series of deals and hand-shake agreements that leave a murky, opaque scene to those trying to deduce exactly what comes in these small black boxes. As such, the Internet is aswirl with rumors regarding what RPX 25 “really is” with the leading theories contending the film is Agfa Aviphot 80s. While there is some evidence that suggests this, or at least suggests the film may have once been this, we are pretty skeptical that it is actually Aviphot 80S in RPX 25 boxes. This is mostly due to the differences between the data sheets for each of these films, and while data sheets are certainly not the be-all-end-all of determining if these two films are the same or different, it is a pretty compelling piece of info in our estimation, especially considering that Maco already distributes Rollei Retro 80S which does seem to essentially be Aviphot 80S and has a data sheet to match. This is all to say that if you want to delve into the murky origins of these Rollei films, be prepared for a bit of a wild ride down a rabbithole. Meanwhile, our best advice is to focus on taking the film at face value, looking at its qualities and figuring out the best use of them. So let’s get started on that, shall we?

Need a slow film for your pinhole cameras? Look no further than RPX 25. Image made with a Reality So Subtle 6x6 Dual Pinhole camera.

Rollei RPX 25’s most defining characteristic is its extremely low speed. It is one of the slowest - if not in fact the slowest - panchromatic emulsion on the market. While there are slower b&w films they tend to be orthochromatic or orthopanchromatic. This ultra-low ISO helps the film play a couple important roles. Obviously, it is a great way to be able to extend shutter speeds even on bright days. We like RPX 25 in our pinhole cameras, for example, because on a sunny day our standard ISO 100 films result in somewhat awkward 1/4 or 1/2 second exposures. RPX 25 can push those exposures out to 1-2 seconds which can be helpful if you are using a pinhole camera without a provision for cable release - such as a Reality So Subtle or the basic versions of the Zero Image cameras. But these extended shutter speeds can work just as well for any other camera as well. Take a roll of RPX 25 and pair it with a three-stop ND filter and you can shoot slow enough with almost any camera to get a bit of motion blur in your daytime images where not usually possible.

The film’s low ISO isn’t solely a benefit to shutter speed though, it can help out aperture as well. Some of us have really fast lenses that produce wonderful bokeh when used wide open, but keeping your aperture at f1.2 or f1.4 on a bright day can be tough and next thing you know, there you are at f8 or f11 and that defocused background is long gone. Not so with Rollei RPX 25. With RPX 25 in your camera the Sunny 16 rule suggests an exposure combination of 1/1000 and f2.8 for a bright sunny day, and if you have a camera capable of a top speed of 1/4000 then that aperture can open up to f1.4! There you go.

Helping extend shutter speeds during daylight exposures is just one of the things Rollei RPX 25 does well. Note the mottling this image shows, we’ll talk more about that later. Image made with a Hasselblad 500C.

Another big benefit of that lower ISO is very fine film grain. Rollei RPX 25 has fine enough grain that if you are using it in 120 you will be hard-pressed to ever notice its grain. Even in the 35mm format RPX 25 produces results with minimally visible film grain. It’s kind of like getting medium format results out of your favorite 35mm SLR. Along with fine grain, Rollei RPX 25 also boasts pretty impressive resolution. The film is super sharp and extremely detailed. Pair it up with a great lens and you will be amazed at what you can pull out of an image, or how large you can blow the negatives up in the darkroom.

Pro tip: Develop RPX 25 in a developer that enhances sharpness such as Rodinal and really up the detail and resolution of your images!

Next we get to RPX 25’s contrast. This is where it differs the most from RPX 100 and 400. Whereas those films have softer contrast and subtle tonality, RPX 25 goes the other way and has fairly high contrast. This produces punchy images with deep shadows and bright, white highlights. It is not a look well-suited for all lighting conditions and if you are using it in harsh light just be forewarned that it is going to exaggerate the contrast already present in the scene. For a long time this threw us off a bit with RPX 25. Our first introductions to the RPX films were through the 100 and 400 emulsions and we expected to find the 25 similar, just slower. But that is definitely not the case and worth remembering if you are using RPX 25 with either of the other two and hoping for consistency across the images. One idea to try that we have not had a chance to test ourselves yet is to expose RPX 25 at ISO 12 and then pull it a stop in development. This should help flatten the film’s high contrast a bit.

This shot from Smith Rock State Park in full, direct sunlight shows how contrasty RPX 25 can get. It is also a great example of how fine grain and sharp the film can be. Image made with a Bronica SQ-Ai.

The last benefit of RPX 25 we’ll throw at you is the emulsion of the film comes on a very thin and clear polyester base. The upshot of this clear base is that RPX 25 instantly becomes a prime candidate for positive processing and turning into a black and white slide film. While you can do this yourself in the home darkroom, there are a few professional labs sprinkled around the world that offer this service as well. The one we have had the most experience with is DR5, located in Stuart, Iowa. While they offer a variety of film developing and scanning services, their specialty is reversal processing of B&W film. If you have never experimented with positive processing of black and white, we cannot recommend it enough. There is something magical about slide film in general, but because of how rarely it is seen, black and white slides are especially captivating. Rollei RPX 25 is one of the films that DR5 most highly recommends for positive processing, hence why we chose it for testing out in this process. So, if you needed a bit more incentive to pick some RPX 25 up, try a roll through DR5 and see some B&W slides with your own eyes. You won’t forget that experience anytime soon.

Rollei RPX 25 might look more beautiful when reversal processed into positives than it does when developed into negatives. Image made with a Fuji G617 and developed by DR5.

The reversal process that DR5 does also seems to help tame some of Rollei RPX 25’s contrast and produces images with more tonal range. Image made with a Fuji G617.

Alright, do we have you convinced to try a roll of RPX 25 yet? If so, that’s great! But before you plunge in there is one caveat we need to share with you. Lately we have been seeing issues of mottling in RPX 25 images. This mottling is caused by a reaction between the emulsion of the film and the backing paper wrapped around, thus it only affects the 120 format. Rollei RPX 25 in 35mm and 4x5 are just fine, but we have noticed an concerning number of 120 rolls showing a mottled texture in the developed negatives. Of the last four rolls we shot in order to produce sample images leading up to this Film Friday, half the rolls had some degree of mottling. Then again, two of the rolls were perfectly fine. The research we have done into the subject suggests that this is something most likely triggered by environmental factors while you are out with the film in your camera, the most likely culprits being humidity and heat. So if you are looking to shoot some of this film in 120 our advice is to first off get through the roll quickly and develop it right away, second avoid high levels of humidity with this film, third is only store it in the refrigerator if it is still in its original, sealed foil packaging and never after the film has been through a camera. It is a vexing problem and one we are still working on pinning down. It has not been enough to dissuade us from using the film, or encouraging you to try it out, but it is also one that has to be pointed out. This is an issue that has cropped up on several of the Rollei films over the past couple of years and even an issue that Kodak struggled with recently and required them making significant changes to their backing paper technology.

This image was mis-exposed at ISO 100 (operator error) and also shows some of the mottling caused by the backing paper reacting to the film emulsion. It was carried around for a week on the Washington coastline and the rainforests of the Olympic Pe… — This image was mis-exposed at ISO 100 (operator error) and also shows some of the mottling caused by the backing paper reacting to the film emulsion. It was carried around for a week on the Washington coastline and the rainforests of the Olympic Peninsula and was likely affected by the high humidity. Image made with a Hasselblad 500C.

To sum up, Rollei RPX 25 offers the intrepid B&W photographer some distinct advantages. It’s slow speed can help enable longer shutter speeds or wide open apertures, even in bright sunlight. It boasts super fine grain and high levels of resolution and sharpness. The film’s contrast makes for dramatic images. And it is available in the trifecta of film formats: 35mm, 120 and 4x5. It has extended red sensitivity than makes skin tones glow in portraiture and cut through atmospheric haze in landscape images. It can even be paired with an R72 filter to produce infrared results (though there are other infrared films we’d recommend ahead of RPX 25). And if you are really looking for a fun experiment, the film lends itself well to reversal processing and the creation of B&W slides. On the flip side, the Rollei films have been plagued with issues such as defects in the emulsion or mottling caused by backing paper in the 120 formats, so they do need to be approached with some caution or just don’t shoot anything extremely important on this film til you have tested it a bit yourself.

With all that in mind, we typically keep Rollei RPX 25 in stock across all three formats and it can be found in our web store by clicking right here.

We’ll wrap up this Film Friday review like we always do, with one last round of some of our favorite RPX 25 images.

Another image from the roll we had DR5 reversal process for us. You only get four exposures when shooting 6x17cm frames, so you try to make every shot count. Fuji G617.

Rollei RPX 25 has red sensitivity extending out a bit beyond 750nm. Even when used unfiltered, this sensitivity can help skin tones give off a glow, as seen here. Image made with a Bronica SQ-Ai.

We have often enjoyed using RPX 25 in our pinhole cameras. The combination of slow film with slow camera generally works out well. Here we crammed our Reality So Subtle 6x6 down the barrel of an artillery cannon found at a local state park.

Rollei RPX 25 is normally a pretty high contrast film, but that characteristic is really secondary to how the photographer uses it. In the right hands and used properly, it can produce lovely images. Photo made with a Bronica SQ-Ai.

A bit more pinhole fun with the Rollei RPX 25, this time at the Satsop nuclear power plant. Image made with a Reality So Subtle 6x6.

Film Friday - August 16th, 2024. Rollei RPX 25