Spur Acurol-N revisited

By Omar Ozenir

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New Mosque, Istanbul, 2013 - Kodak Tmax100 developed
in Spur Acurol-N

Some of you may have read Bruce's review of SPUR Acurol-N coupled with 35mm Delta 100 film here. This post is a further exploration of Acurol-N, this time with two medium format films, Rollei Ortho 25 and Kodak Tmax 100.

Sometime back in summer SPUR kindly sent me two rolls of Rollei Ortho 25 and a 50ml glass bottle of Acurol-N. On their web page this combo was announced with the following imposing headline: "Sharpness Sensation". Well, that created an itch and I was eager to see for myself what was in the waiting.

Have you ever photographed with an EI12 film? Let me put it this way: the speed of Rollei Ortho 25 in Acurol-N is around EI12-16 and exposing the whole 12 frames on a single roll took me several months! Obviously an important factor in my being extremely selective about when to press the shutter is that I had only two rolls at hand and wanted to make the best out of them (neither Rollei film nor any Spur products are readily available in Turkey).

When I eventually developed the first roll of Ortho 25 I was a bit dismayed. Checking the negs with a loupe it seemed as if either the film emulsion had some problems or there was a lot of dust floating around the bathroom. All the hundreds of rolls of perfectly clean negs so far induce me to rule out the latter. In any case, I wrote to Spur about the issue and they were very helpful (thank you Anita Schain).

I always use bottled drinking water for my film development and that's what I did with Ortho25. SPUR on the other hand strongly advise the use of distilled water. I took note of this, loaded the Rolleiflex with the second roll of Ortho 25 and over the ensuing weeks again only took a picture when a suitable subject presented itself.

350 Years Young

As I emerged from an underpass in Eminonu (at the tip of the Golden Horn) one day and had the full view of the 350 year old New Mosque in front of me I had two frames left on my second Ortho 25 roll. The picture I composed in my minds eye looked promising. The stairs and flow of people could lead the eye into the picture. People would turn out mostly blurry but I hoped a few relatively immobile ones could help provide points of interest.

The movement in the foreground would be a nice contrast against the architecture in the background: the flow of life and passage of time against 350 years of solidity and continuity. The minarets would have to be cut off, but I didn't see this as a major problem; on the contrary, I liked the idea of going against convention. Including all the height of the minarets can also introduce too much sky, weakening the picture...been there, done that.

Anyway, I squeezed into a small spot, set up the tripod and exposed the remaining two frames of Ortho 25. I immediately reloaded with Tmax 100 and exposed a few further frames, because I wanted a direct comparison of Ortho 25 with Tmax 100 in Acurol-N.

Here I'd like to shortly digress to Tmax 100 and return to Ortho 25 later. I do wonder what you think about Tmax100. From what I gather what's out there on the www, it's got its few admirers but many dislike the film. I'm one of those who over the course of years hasn't been able to fall in love with Tmax 100 (Tmax 400 is a completely different story), because the tones in fine grain developers like D76 or XTOL just look...well, what Bruce would call dreich...to my eyes.

On the other hand, because of it's amazing resolving power I've always been on the lookout for a way to use it. I think Tmax 100 needs an acutance developer like Rodinal, which increases, as you will know, edge sharpness. There just isn't much point in using a fine grain developer to etch away some more of the grain as the film is already extremely fine grained anyway.

I understand that Acurol-N belongs to the acutance type of developer family. At least, that's what I infer from the high dilution ratios which range between 1+50 and 1+100 for normal contrast with most films. On their web page Spur don't classify the developer but simply claim "fine grain, high resolution and extraordinary plasticity".

I developed four rolls of Tmax 100 with Acurol-N and although every sane man should doubt the validity of judgements based on such a tiny sample I have to say that the results so far have been nothing but outstanding. Amazing sharpness, lovely tones and controlled highlights that print easily.

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Kodak Tmax100 negative developed in Acurol-N
(click to enlarge)

The main photo at the top is a print from Tmax 100. To check how this neg fared in terms of grain and resolution I raised the enlarger head to max height - which yields a print size of about 17"x17" - and made a partial enlargement from the disgruntled guy in the centre of the frame on a suitably sized piece of paper. You can view the full 300dpi scan below. Note the wiring in the window frame in the background: it is clearly resolved.

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Detail from Tmax100 developed in Acurol-N
(click to enlarge)

The next detail is from Ortho 25, for which I used  distilled water this time and which turned out much better than the previous blunder. Again, checking the wiring in the window frame we can say that the resolution is slightly higher compared to Tmax 100. In terms of grain, a 17"x17" print from Tmax 100 shows very little of it, whereas a print of the same size from Ortho 25 has none at all!

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Detail from Ortho25 developed in Acurol-N
(click to enlarge)

Despite the very impressive results I can't say that Ortho 25 is an easy film to handle. First of all, it just doesn't lie flat and keeps rolling unto itself despite many days under heavy weight. I've never seen such an impressive display of stubbornness! How funny that the official spec sheet says that the film has a "non-curling backside coating to improve film flatness".

On top of the curliness, I suspect that the emulsion is rather delicate when wet, at least compared to other makes. I'm not sure how it came about, but there are scratches in the emulsion; these can be seen in the upper right corner of the Ortho 25 neg below. Recently I've developed the ugly habit of swiping down wet 120 film between my fingers - also wet of course - to aid even and quick drying, and haven't witnessed any problem with other films.

The scratches must be the result of either this swipe, or the sharp corner of the film touched the wet emulsion when it rolled back up. Basically, I'm not sure and I can't pass a final verdict after developing just two rolls. A persistent soul might well be able to tame Ortho 25.

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Rollei Ortho25 negative developed in Acurol-N
(click to enlarge)

For the photographer who seeks the ultimate in fine grain and resolution and who also does not mind the regular use of a tripod, Rollei Ortho 25 could be a film well worth persevering with, despite some of the difficulties I've described. My preference is for Tmax 100 due to the speed advantage (EI50) and tonal qualities in Acurol-N.

Finally, let me share a pic of the print at the top. It is a print from the Tmax 100 neg on 12"x16" Forte Fortezo paper:

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Click to enlarge

UPDATE: Bruce writes, "Re. the curliness of Ortho film that Omar highlighted - here's how I straightened out a roll I shot. Made a bit of a difference but still almost took my eye out when I "released" it!'


  1. Excellent reading I must try some Acurol-n. I have used ortho 25 and found it to be good stand developed 1-200 in rodinal(aph09) 60 mins.I have only tried the ortho 25 in 5x4 format but the box i purchased had badly cut film being 1mm oversize causing it to curl in the film holder so the remainder sits in my freezer. Of course shooting my 5x4 in a monorail the film speed is not such an issue. Must try it again in the new year . thanks for the review.

  2. Excellent story. I love Omar's contributions to this blog. Thanks