Developing Kentmere 400

Craig · Jun 14, 2025

I have run a few rolls of Kentmere 400 now, and I have found it is sensitive to over-development. I used a Jobo and forgot to deduct 15% from the time for continuous agitation. As expected, the negatives were denser, but also noticeably larger grain than Kentmere developed using the datasheet times with correction.

I have not noticed nearly as much grain growth with over-development with other Ilford films. If you shoot Kentmere 400, it pays to be precise with the developing time! I have found it to be much less forgiving of development variation than HP5 for example.

Andrew O'Neill · Jun 14, 2025

Interesting. Thanks for sharing, Craig. I've got heaps of both the 400 and 100 120 rolls that I need to start playing around with. What developer did you use?

Craig · Jun 14, 2025

Andrew O'Neill said:
What developer did you use?

ID-11. I usually use Xtol, but these were important negatives and the data sheet only has times for Ilford developers ( except for D76). I have used ID-11 in the past plenty and it's a great developer, so I mixed a fresh batch for these films and used it one shot.

I would definitely do some clip tests and dial in your developing time for your workflow before processing anything important.

Lachlan Young · Jun 14, 2025

The much stronger development inhibition effects of Ilfosol 3 makes it a better choice (broader error bars for overdevelopment).

koraks · Jun 14, 2025

RPX400, 35mm Instant Mytol 1+1 12 minutes, manual agitation (Paterson tank)

RPX400 35mm Pyrocat HD 1+1+200 minimal agitation; 3 cycles at 20 minute intervals

RPX400 35mm Pyrocat HD 1+1+100 15 minutes rotation in Jobo

RPX400 35mm Instant Mytol 1+0 8 minutes rotation Jobo

All scans with Minolta Scan Dual IV at 3200dpi. Images are sharpened with USM for crisp grain (not necessarily image detail).

As you can see, the first example of the glass greenhouse in the El Retiro park in Madrid is pretty darn grainy. The cause here is mostly because it's a very dense negative. Variations in development also give some variation, but it's much more subtle.

If you're optimizing for grain, you need to nail exposure. This IMO is really the main thing. With development you can nudge things left or right a little, but the main impact (given a particular film) is how you meter the scene.

RPX400 as such is not a super-fine grain film, but it's quite alright; HP5+ definitely has an edge on it in this respect as well as effective film speed.

Of course how you scan (or print) and post-process makes a huge difference, too. I could have presented the above as almost grainless, buttery smooth images if I had scanned them with my flatbed at 1600 dpi.

Sanug · Jun 14, 2025

For me, overdevelopment is not such an issue, but overexposure. I had much better results at ISO 800 than at box speed. Development in Adox XT-3, 1+1, 16 Min. with Ilford agitation.

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koraks · Jun 14, 2025

Sanug said:
For me, overdevelopment is not such an issue, but overexposure.

IDK the cause as it can be several but you have lots of blocked up shadows as well as blown out highlights in the example you posted. Maybe the print is different. The digital version I would personally consider highly problematic if it were my work.

retina_restoration · Jun 14, 2025

koraks said:
If you're optimizing for grain, you need to nail exposure. This IMO is really the main thing. With development you can nudge things left or right a little, but the main impact (given a particular film) is how you meter the scene.

Agreed. As you lean more and more towards overexposure, grain becomes more conspicuous (larger, more intrusive). Unless development is truly excessive (way more than 15% over optimal), then modest overdevelopment is not going to have a big role in how the grain looks, at least compared to overexposure. IME, Kentmere is more sensitive to overexposure than it's more costly Ilford equivalents (HP5 and FP4).

To the OP I would add one point; ID-11/D-76 (for all practical purposes the same developer) combines Metol and Hydroquinone, and the two have a fairly strong superadditive effect. This can work against you if your image has lots of exposure in the very high values, leading to dense, blocked highlights. I find D-76 works well for images that do not have a very wide range of values, but if I know there's a broad range between dark shadows and very bright highlights, I would avoid it and choose something more compensating, like a 2 bath developer, (Developing agent and accelerator in separate baths) or PMK. Using ID-11 and continuous agitation only amplifies the "hot highlights" effect. Personally, that's something I would avoid.

albireo · Jun 15, 2025

Craig said:
I have run a few rolls of Kentmere 400 now, and I have found it is sensitive to over-development. I used a Jobo and forgot to deduct 15% from the time for continuous agitation. As expected, the negatives were denser, but also noticeably larger grain than Kentmere developed using the datasheet times with correction.

I have not noticed nearly as much grain growth with over-development with other Ilford films. If you shoot Kentmere 400, it pays to be precise with the developing time! I have found it to be much less forgiving of development variation than HP5 for example.

I've used little HP5+ but loads of Kentmere 400. I agree that both exposure and development variations can have a dramatic effect on the quality of the final result.

However, I haven't noticed Kentmere 400 to be special in this respect. It is true for all the films I've used. Perhaps HP5+ is the exception in being especially forgiving of development differentials?

In general, I don't find 15% development time errors to be uncommon or excessive at all. Many people routinely overdevelop their film. Not always their fault, as often published tech sheet report development times well in excess of 20% more than what I'd consider optimal in my workflow. This is becoming increasingly common I find. For example, the Maco/Rollei tech sheet recommendations for their 'Retro' (Aviphot) line of products are completely bonkers and are probably designed to give something like a 'usable' negative when exposing them at box speed or close to it (so dramatically underexposed). Harman is going the same way with their Kentmere 200 product, I suspect. The most convincing test I've seen suggests it's more of a 125EI film marketed as a 200EI-capable product via mild underexposure and overdevelopment.

People love to moan about Foma marketing unrealistic box speeds, but many others are at this as well, though perhaps more subtly.

Lachlan Young · Jun 15, 2025

albireo said:
suggests it's more of a 125EI film marketed as a 200EI-capable product via mild underexposure and overdevelopment

K200 seems to deliver about 1.15-1.2 density units above base & fog before the highlights hit the wall (that's in real-world usage, rather than a step wedge).

There's a persistent tendency to try and accuse manufacturers of being 'unrealistic' - when often the opposite is true - they have a much clearer understanding of the shortcomings of their budget aimed products and are making rating recommendations to prevent inevitable end-user misuse (or stronger words) causing greater problems.

albireo · Jun 15, 2025

Lachlan Young said:
K200 seems to deliver about 1.15-1.2 density units above base & fog before the highlights hit the wall (that's in real-world usage, rather than a step wedge).

There's a persistent tendency to try and accuse manufacturers of being 'unrealistic' - when often the opposite is true - they have a much clearer understanding of the shortcomings of their budget aimed products and are making rating recommendations to prevent inevitable end-user misuse (or stronger words) causing greater problems.

The most beautiful examples of Kentmere 200 I've seen were exposed at 125EI and tested by a retired professional photographer with 60 years of experience. They were gorgeous images.

Have you taken any pictures with Kentmere 200? Is it possible to see your results?

{Moderator's deletion - keep it civil!}

Milpool · Jun 15, 2025

Yes, the Harman tech sheets for the K films clearly indicate ISO speeds (processed with ID-11). It seems unlikely to me those would be false statements on the Kentmere tech sheets while they are true for the Ilford films. At the very least if the statements were intentionally incorrect I’d expect weasel wording rather than clear indications which even include the developer used (not a requirement to disclose unless requested).

People should also be reminded the ISO speed measurement includes a contrast parameter. It doesn’t make much sense to say two films with the same ISO speed have different “contrasts” unless the shapes of the highlight portions of the characteristic curves are wildly different.

Lachlan Young said:
K200 seems to deliver about 1.15-1.2 density units above base & fog before the highlights hit the wall (that's in real-world usage, rather than a step wedge).

There's a persistent tendency to try and accuse manufacturers of being 'unrealistic' - when often the opposite is true - they have a much clearer understanding of the shortcomings of their budget aimed products and are making rating recommendations to prevent inevitable end-user misuse (or stronger words) causing greater problems.

albireo · Jun 15, 2025

Milpool said:
Yes, the Harman tech sheets for the K films clearly indicate ISO speeds (processed with ID-11). It seems unlikely to me those would be false statements on the Kentmere tech sheets while they are true for the Ilford films.

For the record, Kentmere 100 and 400 are very close to box speed in my workflow.

I have yet to try some of the new Kentmere 200, but I've seen some surprisingly thin negatives from reviews of people exposing at box speed. Might be user error, sure. I guess the final word, for me, will be my own test. My trusty Heiland TRD never lies.

What were your own experiences with Kentmere 400? What densitometer do you use for your own tests?

John Wiegerink · Jun 15, 2025

ISO EI blah, blah, blah! It's talked to death here, but it probably always will be. Why? Because we all meter things differently, our meters don't always read the same, our developing isn't the same, our post printing/processing isn't the same and we don't interrupt the scene we're photography the same. The manufacture just gives us a starting point and that's all. Is it the right one for all of us? Nope! Is it the right one for some of us? Yup! It might be better if the manufacture gave use a three point ISO rating system, but they don't. A 400 speed film is my example. You know, like ISO 200 gives superb results, ISO 400 gives excellent results and ISO 800 good results. Even then not everyone would be happy. Like Rick Nelson's Garden Party song says, "You see, you can't please everyone so you got to please yourself".

albireo · Jun 15, 2025

John Wiegerink said:
ISO EI blah, blah, blah! It's talked to death here, but it probably always will be. Why? Because we all meter things differently, our meters don't always read the same, our developing isn't the same, our post printing/processing isn't the same and we don't interrupt the scene we're photography the same. The manufacture just gives us a starting point and that's all. Is it the right one for all of us? Nope! Is it the right one for some of us? Yup! It might be better if the manufacture gave use a three point ISO rating system, but they don't. A 400 speed film is my example. You know, like ISO 200 gives superb results, ISO 400 gives excellent results and ISO 800 good results. Even then not everyone would be happy. Like Rick Nelson's Garden Party song says, "You see, you can't please everyone so you got to please yourself".

Hear, hear!

Milpool · Jun 15, 2025

Sort of. Assuming the ISO speed is correct (Kodak, Harman, Fuji) it is really the metering that causes differences (or in the case where people are doing tests, the test methodology and criteria). The other things people go on about when it comes to “personal EI” are mostly red herrings.

It should also be said unless you are trying for the absolute best image structure (granularity, resolution…) a film can give, there isn’t really anything to lose by setting the meter say 1/2 to 1 stop lower than ISO speed either, so it probably isn’t worth all the arguments.

John Wiegerink said:
ISO EI blah, blah, blah! It's talked to death here, but it probably always will be. Why? Because we all meter things differently, our meters don't always read the same, our developing isn't the same, our post printing/processing isn't the same and we don't interrupt the scene we're photography the same. The manufacture just gives us a starting point and that's all. Is it the right one for all of us? Nope! Is it the right one for some of us? Yup! It might be better if the manufacture gave use a three point ISO rating system, but they don't. A 400 speed film is my example. You know, like ISO 200 gives superb results, ISO 400 gives excellent results and ISO 800 good results. Even then not everyone would be happy. Like Rick Nelson's Garden Party song says, "You see, you can't please everyone so you got to please yourself".

Milpool · Jun 15, 2025

albireo said:
For the record, Kentmere 100 and 400 are very close to box speed in my workflow.

I have yet to try some of the new Kentmere 200, but I've seen some surprisingly thin negatives from reviews of people exposing at box speed. Might be user error, sure. I guess the final word, for me, will be my own test. My trusty Heiland TRD never lies.

What were your own experiences with Kentmere 400? What densitometer do you use for your own tests?

I haven’t ever used a Kentmere film. I’m just going by the data sheets provided by Harman.

The testing I have done on films, developers etc. were pretty much always about the sensitometry / exposure theory / tone reproduction theory / chemistry themselves. I use(d) a sensitometer and densitometers for exposure and measurements, along with visuals where applicable. It was largely investigative / learning. None of it really impacted my photography and printing.

When it comes to meter settings my view remains that if the ISO speed is correct (Kodak, Harman, Fuji) there is little point in going through the effort / expense of running a “personal EI test” at the outset since it doesn’t really tell you anything about print quality if you understand these tests. Instead I recommend people start out one of two ways:

1. ISO speed, or
2. 1/2 - 1 stop lower than ISO speed if desired since this is what most EI test methods, Zone System etc. will give you (by definition)

Then you go to work making pictures and printing/scanning and if there really is a personal EI you home in on that based on whether you consistently find yourself dealing with too thin or needlessly dense negatives.

Anyway that’s what I’ve learnt. Take it or leave it - in the end I’m just some random person on the internet like everyone else here.

If you do end up testing Kentmere 200 I’d be curious to see what you come up with.

Craig · Jun 15, 2025

albireo said:
I have yet to try some of the new Kentmere 200, but I've seen some surprisingly thin negatives from reviews of people exposing at box speed. Might be user error, sure. I guess the final word, for me, will be my own test. My trusty Heiland TRD never lies.

I have only shot one roll of K200 so far, exposed at box speed and developed at the datasheet time in ID11 and it gave very nice negatives. I'd consider 200 to be a correct speed. My negatives printed nicely on a grade 2 paper.

albireo · Jun 15, 2025

Going back to Kentmere 400, I have just noticed that the official tech sheet here

https://www.ilfordphoto.com/amfile/file/download/file/1959/product/2136/

has slightly different times for ID11 and D76:

Which I thought was surprising. I have not tried ID11 but Adox D76 1:1 and have personally settled, for normal to high contrast scenes, with exposing at 320EI and developing for 12 minutes. I'm finding this a good compromise between speed utilisation, grain structure, and even dynamic range.

An example in 35mm (I use the same recipe for 120)

Craig · Jun 15, 2025

Looking at the sheet I am also surprised there is no time given for Perceptol stock, only 1:1.

Craig · Jun 15, 2025

albireo said:
Which I thought was surprising. I have not tried ID11 but Adox D76 1:1 and have personally settled, for normal to high contrast scenes, with exposing at 320EI and developing for 12 minutes. I'm finding this a good compromise between speed utilisation, grain structure, and even dynamic range.

I assume you use intermittent agitation in a small tank for this time? I might try that time/dilution and see what I get.

albireo · Jun 15, 2025

Craig said:
I assume you use intermittent agitation in a small tank for this time? I might try that time/dilution and see what I get.

Apologies yes - 1 or 2 reel Paterson tank, constant inversions 1st minute, then 1 inversion at the beginning of each minute.

Lachlan Young · Jun 16, 2025

albireo said:
Have you taken any pictures with Kentmere 200?

Yes. That's why I was able to tell you the density at which the highlights go off. You might not be able to tell that from a step-wedge test.

I was trying to suggest that you might have a hard time getting it to hold and reproduce more than 7-stops of usable information, no matter what you do - and that that you will need to expose to protect highlights (unless you want/ need the highlight effect - which can be quite striking), with shadows falling where they will.

Exposed with reasonable respect, it's perfectly capable of good results, just don't expect it to be manipulable in the manner of HP5+ etc. Work with what it does well, don't try and overly neutralise it.

Craig said:
I am also surprised there is no time given for Perceptol stock

Probably because so few use it. I'd be unsurprised if it ended up very close to the 15-16m range (1+1 D-76/ ID-11 times are often very close to stock Perceptol times - and those D-76/ ID-11 time variances often relate for whatever undisclosed reasoning to Kodak vs Ilford's preferred 'normal' aim contrasts - once you know the aims and error bars & normalise them properly, you'd be shocked at how many emulsions can be run together and deliver often better results than stuff run individually that people have sweated over the most irrelevant details of, then screwed up their agitation, temperature management etc).

Developing Kentmere 400

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