ice floating in a glacial lagoon

Developing Slide Film – Not for the Faint Hearted – by Laura Cogan

This will be a mish mash of part review, tutorial and warning to all mankind about the perils of developing slide film.

I have a love-hate relationship with colour film of late. I’m still very much a black and white girl at heart but I wanted to see what all the fuss was about. I decided to give Ektachrome E100 another bash on a bigger scale than my last attempt. Only this time I’d develop it myself. Bear in mind I’ve never developed any colour film before so I knew I wasn’t doing myself any favours to start with. But in true Laura fashion I decided to jump in face first. Go big or go home right?

I’d arranged with a local campervan company to write a blog piece for them of a typical road trip for me and the Hobbit using one of their vans. Honoring this company being the brightest coloured mother-humpers on the campervan circuit I decided this was the perfect opportunity to go balls deep into Ektachrome. I went out and bought five films for the occasion (then promptly went to sell a kidney after I realised how much five of these bad boys cost!). So with the place and time set, the gold nugget costing films ready to burn, I just needed to sort out some chemicals to develop with. Sadly something not available here.

tetenal colortec e6 kit
The six bottle Tetenal Colortec E-6 kit

Importing chemicals can be a little tricky at times, I’ve come up against this before. I was recommended the Tetenal colortec E6 kit through Fotoimpex. I’d been told even though the website says they can’t ship to Iceland, if you send them an email they will give you an invoice through paypal and ship with the regular postal service. Worth a punt I thought.

Eventually I managed to sort this out with the fine folks at Fotoimpex. It took a bit of time because of paypal links not working how they should. But after being squeezed for additional ransom to the Icelandic post office I managed to get the kit in my hands the day before the roadtrip. All six bottles of it! It says it’s a three bath kit so this was a little confusing to find it had six bottles. But I just filed it under “Problems for Future Laura” to figure out and put it out of sight in my darkroom until a later date.

Time for the big roadtrip dubbed “the road trip of firsts”, you can read all the ins and outs of it here if you like. But in terms of shooting entirely in colour, man alive, that was a lot harder than I anticipated. The weather was bordering on shit for most of the weekend which gave the most BORING light with fleeting moments of utterly belting. So in terms of colour, I wasn’t feeling it.

small waterfall with houses nearby
Flat light day but happy with the texture in this one

I’m so used to black and white that it’s become second nature that I can make any lighting situation work. In colour I’m still a noob so my expectations of what I want to achieve are too high. I need to learn what I can and cannot pull off.

There were moments of pure unadulterated joy though. Like when the clouds fucked off for just a second and let in a ray of light to take away from the flatness of everything. Or with the simply unbelievable golden light we got at the end of one day which later turned into glorious pink skies. These were the shots I was most excited to see and had almost a desperate feeling of hoping they’d come out. I love that feeling on a road trip, those are the images I remember the most and are usually my best.

snow covered mountains and pink sky
Gorgeous pink skies

I got a bit snap happy on occasions to the point I felt annoyed about wasting shots. Taking an entire film at the bloody waterfall I nearly died hiking to (not at all being dramatic, it was hell). Or several shots of a landmark I’ve photographed a million times already. I know I’m only gonna use one or two shots at most from these places but yet my brain has a hiccup at the time and the next thing I know I’ve rattled off several frames! Grr!

In conclusion (for the shooting) I do have a place for colour film in my arsenal, it just has to be a side hustle instead of a main event. Even though when I tried this before I found it difficult thinking in black & white and colour at the same time but it’s the lesser of two evils. I just need to suck it up and practice. If you knew me you’d know I’ve got the patience of a toddler so we’ll see how it goes.

skogafoss waterfall
I might have photographed it a ton but never in blue!

Road trip over, time to get that Tetenal box back out and figure out what the crack is with it. Before I jumped straight in I did more research online of anyone who has used this kit, or developed slide film in general. I quickly learned no one does it the same way. I’m not exaggerating when I say I didn’t find one video where it didn’t seem like utter chaos.

Some of these people weren’t using regulated temperature water, which I’d understood to be the number one rule. In one case literally running a tap and waving a thermometer around proclaiming ”seems about right”. One common theme in each video was no matter how they did it or how batshit crazy the process seemed, they all got film with pictures in the end. In my befuddled brain I found this encouraging that surely I couldn’t fuck it up so badly.

Organised to the max

We already had a sous vide for regulating the temperature. The Hobbit had got over excited after my initial musings about developing colour, he declared we could share it and bought one. He’s been sous viding everything in sight, he’s an unstoppable sous vide monster. Even as I write this I can hear the gentle buzzing of ribs being boiled in plastic for hours on end.

With all other accessories purchased I just needed a stirrer for the tank agitations. The one that came with the Paterson tank years ago has been lost with time. I settled on a pair of scissors wrapped in blue duct tape (without the tape it sheared the plastic off the tank). They fit in the hole and worked just fine for a substitute.

The Tetenal instruction manual needed to be read a few times to understand the madness. I must admit I was a little bamboozled by these. I had to get additional help from the kind internet people who had documented their experiences with it.

tetenal instruction manual
Deciphering the mixing instructions
tetenal instruction manual
Fighting Fahrenheit

I was a little flummoxed by the idea you can reuse a developer, I’m so used to one shot chemicals for black and white. But the manual clearly (ish) states you can develop up to six films with 500ml of working solutions so that’s what I went with in the end. The original plan was to develop two at a time using the 1000ml solution but A. the bottles to hold 1000ml were twice the price of the ones I bought and B. if I fucked it up on my first try I’d ruin double the films. Safer to stick to the 500ml and do one at a time, learn as I go.

Another note about these instructions is some of the temperatures are only in Fahrenheit, the devil’s measurement of temperature. Stupid bloody system. In light of this and the fact the instructions were written in young people’s eyes font size I wrote out just the bits I needed. Stuck them on the wall of the darkroom to follow as I go. I included all the steps, agitations and rinses etc. Absolutely smashing it I thought. Organised to the MAX.

written out instructions
Super organised own instructions

There’s a part on the instructions that gives a stark warning about mixing first developer and keep it air tight before you do the colour developer. Even a tiny bit of air pollution between them will ruin the first developer. I took this as a credible threat so I would see to it that NOTHING goes near this first developer. So I bought it’s own funnel. Not a drop of anything else but the first developer or water was going down it’s spout. First developer is a diva and must be treated as such.

First developer diva funnel
Diva first developer funnel

The calamities started early. Like not having a dark coloured sharpie to write on the bottle labels with and having to do it with silver, then over it again with gold. I also had the Hobbit’s digital thermometer for quick accuracy for my rinse water temperature. But I dropped the buggar in the box of hot water and death took it within the first minute of prep.

box of water
Death to thermometers box

Preparation calamities seemingly over, I’d no issues mixing the chemicals. However, I did have a problem keeping the bottles from floating in the water. I ended up appropriating one half of the Hobbit’s broken chopping board to sit on top of them. Incidentally, the chopping board was my fault. I’d put it in the dishwasher and it snapped perfectly in two, quite remarkable really. I swear we do have fully functioning equipment in our house too, we’re not animals, we’re just clumsy.

chopping board holding down bottles and sous vide
Holding down the bottles

The next stage says to pre-soak the film. This was another point of contention for me. I’ve seen it done two ways, fill the tank with water heated to 38 degrees C or place the dry tank in the water to heat up for five minutes or so. Even though it’s a weird concept to me to put water in the tank first I decided as I’d seen it done on video with no issues I’d give it a go.

bottles in water, sous vide and film tank with jug on
Holding down the tank

Then came the drama of keeping the tank from floating and so I rested the jug on top of it to keep it down. This is all supposed to be the easy part and already I was at about a 10 on the wasps in my brain scale.

middle finger to the development
Fuck this shit already

With the presoak over it was time to get down to the real biz. The overall times increase the more films you do with the same solution but the rinses and agitations stay the same. The first developer went in and the lid left off for agitation with the makeshift scissors-stirrer. Weird concept to me but the other option was to constantly take the tank out of the water for inversions. Agitation is constant for the first 15 seconds and then every 15 seconds after. It just seemed too messy so I went with lid off + scissor-stirrer for the easiest.

scissors stirrer in the tank
Genius blue taped scissors-stirrer

Was it bollocks easy! Found this out after the first 15 seconds when I couldn’t do the maths quick enough of where the chuffing timer would need to be in another 15 seconds. By the time I’d figured it out it was already too late and time for the next one.

Confounding this was the fact the fucking tank kept trying to float. I adopted another method of wedging it in place with the half chopping board, nicely wedging the bottles at the other side at the same time.

chopping board wedging bottles and tank in water
Tank wedgie

The scissors were working nicely until the tape started to disintegrate and then I worried about little blue floaters attaching themselves to my lovely film. No time to deal with that yet though, time for rinse and about half the total agitations already missed.

melted blue duct tape
Not so genius disintegrated blue scissors-stirrer

The instructions state if you’re rinsing with standing preheated water then you have to change the water every 30 seconds. I didn’t trust the volcanic hot water that comes out of the tap here to do moving rinses. This meant over the specified 2.5 minutes I’d have to change it five times. I don’t know how I believed I could keep track of every 30 seconds AND count how many changes I’d done at the same time after the whole 15 seconds debacle. This is the point I lost my shit all together, sweat pouring down my face wondering what the hell I’d gotten myself into.

With five more steps to go after this you can only imagine what state I was in by the end of the first film. That’s right, fucked, there’s no other word for it. I wasn’t expecting usable negatives but more like patchy unusable blobs at best. I’d completely fudged the timings of agitations and rinses, and I’d sweat more than any human woman has any rights to do over a non-sporting enterprise. It was absolute chaos!

slide film with pictures on
First out of the hole

Miraculously there were images on those first negatives and I couldn’t believe it. They didn’t look great in the light of the darkroom but out in the real world (the living room window) they looked a lot better. Although the back of the film was crazy blue so I thought that was the deserved punishment for fucking up the timings.

pictures on slide film
Better in daylight
blue side of a slide film

The Hobbit came home from work part way through the madness and tried to hide until it was over. Hobbits run from danger, it’s in their genes. At one point I’d tried to engage him in the chaos by shouting over my music to “FIND ME THE GIANT BULLDOG CLIP, I NEED IT NOW!!!!!” He didn’t find it and retreated away after being met with sweaty expletives.

Afterwards, when I was sitting down resting with a cold compress he calmly stated perhaps I shouldn’t try doing it with music on. Especially not Muse, which in itself is chaotic music at the best of times and was just egging me on (his words). I was exhausted and still had four films left to do. Not at all enjoying this colour development lark and thinking i’m never doing this again.

I was so prepared, I just didn’t see the chaos coming. Certainly not over maths! I’m a numbers person, it’s a big part of my real life job and I just froze in the moment and couldn’t do multiples of 15 backwards to save my life. Panic set in and I turned to a Muse listening jelly.

instructions with adjustments
Multiples of 15 for the moron in the room

For round two I made some adjustments. First on the list was to add the multiples of 15 on my instructions just in case I went jelly again. Next was to find a new stirrer because I’d melted the last one. I found the perfect one, a disposable craft knife. Finally, I found the giant bulldog clip the Hobbit had failed to find and used it to clip the tank to the side of the box to keep it from floating.

craft knife
Genius craft knife stirrer
craft knife stirrer in action
Like seriously genius right?

There was a lot less chaos this round and I managed to complete all agitations. I also paused the timer to empty and refill in rinses to reduce my blood pressure. Probably should have been obvious the first time. There was no logic and reason in round one, thankfully there was in round two.

big bulldog clip holding film tank to box
The elusive giant bulldog clip doing the biz

The film came out the hole looking fine and included some of the golden light pictures I’d been excited to see. Huge relief! The only notable occurrence this round was the blade in the new stirrer didn’t survive and had taken a thorough bleaching. Thankfully this was an easy fix, removed the blade and back in business with the best stirrer ever.

bleached craft knife blade
The not so genius now bleached craft knife stirrer
new stirrer without blade
The new improved genius craft knife stirrer sans blade

Despite being perfect with timings this round, the back of the film was still quite blue. The first film was drying clear so I was perplexed but not worried. I was posting to my instagram story throughout and people commented that the blue was normal.

slide film with images on
Second out of the hole and bearing eagerly awaited golden light pictures

Two films down, three to go and I was not enjoying the whole experience. I would like to think over time this would become more fun but right now at this moment it was just shit.

On to round three and I’d run out of gloves. Prepared for everything except gloves and chaos. I improvised by using scented lady bags and hair ties. I’m not proud. They were awfully sweaty though. Even after trying to put a couple of air holes in to reduce the sweatiness they were just unbearable and I abandoned them soon after. Didn’t affect the third film which came out with much less chaos.

purple bag on hand
Sweaty lady bag says it all

By this time I’d been at this for several hours and just wanted the whole experience to be over. It was Saturday night and approaching one of my favourite programmes of the year, Eurovision. So rather than dilly dallying around I got straight back in to bash out the last two.

One noticeable change I made with the last two films was the presoak. I decided to give the dry tank a try, wedging it down in the water for five minutes. I wondered what effect it would have on the finished product. The answer is nothing, no effect, they came out the exact same as wet presoak. Take what you will from that.

tank under board for presoak
Jamming down the dry presoak
middle finger
No gloves rebellion

The last two films were done without gloves because I’d lost all giving of shits about it. Thankfully I didn’t melt any fingers. I was happy with the final working set up of wedging the bottles in and clipping the tank to the side of the box. Worked quite well in the end. Mostly I was just glad when it was all over and the films were drying.

final working methods
The final genius working set up

An honorable mention about scanning the negatives with Vuescan. I’d checked the settings and noticed something about infrared clean and thought, no, you don’t belong here and turned it off. I then scanned everything like normal, all 59 negatives, tedious and time consuming.

setting in vuescan
What does it even mean?!

It was only when going through the scans I noticed the sheer amount of dust and fuckery on the images. Like a ridiculous amount. Even though I’d been careful and done nothing out of the ordinary. Of course it was that tiny setting I’d mindlessly unchecked.

before and after scanning with infrared light
Before and after the magic of infrared clean (apparently crucial setting)

I put the setting back on light, rescanned an image and hey presto all the dust shit was gone. I then spent another mind numbing amount of hours rescanning them again. What a dumbass.

long empty road into mountains
The open road, where my heart lies

So to sum it all up. I’m happy with the final results. I hate the development process. There’s definitely room for colour in my arsenal as a side hustle. All hail black and white.

If you like what you see come over and see me at or @hassywonderland on Instagram 🙂

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34 thoughts on “Developing Slide Film – Not for the Faint Hearted – by Laura Cogan”

  1. Marvellously entertaining and informative read. It is so much easier to learn from other people’s mistakes – and you make it so entertaining as well.

    Regarding the floating tanks and bottles have you considered:
    1. lowering the level of water in the bath
    2. putting something heavy in the bottom of the bath and then putting the bottles/tank on top of that
    In effect you only need the water level in the bath to come up to the same height as the fluid in the tank to transfer heat?

    1. thanks Bob. It´s about keeping the water level correct for the sous vide firstly as if it drops below the minimum line it automatically stops. I was more aware of this than anything else. I measured how much water it would need to cover the whole tank and keep the water level correct for the sous vide but at the same time not come over the top into the tank. Not so delicate balance in the end 😀 I like the idea of putting something in the bottom of the tank though if I ever decide to torture myself with this process again.

  2. What a delightful story Laura! I don’t mean to laugh at your trials and adventures but they are just so much fun. Are you sure you were not having more fun than you might admit? Thanks so much for sharing!

    1. you´re welcome 🙂 I´m more than happy for others to laugh at my misery, it´s the only thing making it worth the hassle. Haha no, I genuinely hated it at the time, i´m getting more joy from the after though so there is that. Maybe next time i´ll know how horrible it is going into it so it´ll sting less 😀

  3. Awesome post! I’ve wondered about developing colour and E6, but you’ve probably made the decision for me – I’ll take them to my local lab instead.

    I develop my own B&W, which seems to be about as complicated as making a cup of instant coffee in comparison. Not that things can’t go wrong even there though.

    Anyway, nice results though and hope it was worth all the excitement you had to endure. 🙂

    1. I´m glad that you´re heeding my warnings and not going to put yourself through the torture. My work here is done 😀
      I developed a B&W last week and I was almost dumbfounded by how much simpler it was, no sweaty lady bags required!
      It was kinda worth it, but only a tiny bit!

    1. mi piace il “fanculo” “guantato” !!!!!!
      bravissima, continua cosi.
      … certo che se le “dia” costassero qualcosa meno!!! ciaoAtutti.

  4. Oy oy oy, you got me giggling uncontrollably at the broken chopping board, and I had to stop lest I choke. Back to it, now…

    1. The hobbit still hasn’t forgiven me and continues to laboriously take out both halves from the drawer with a theatrical sigh every time he uses it (which is far more than one should use a broken fucking chopping board!)

  5. Peter Roberts

    I guess I’m like Nige. For years I’ve had a habit of periodically toying with the the idea of doing my own colour developing but have always chickened out.
    Your entertaining post has completely cured me of this.
    Thank you so much. I’m now a contended chicken.

  6. I don’t get it. There’s so much talk about sous-vide for critical temp, critical timing, caustic handling. I’ve recently been playing with E6 and find it really simple and not fussy at all. I use an old electric fry pan for a water bath (it’s not even 1-1/2″ deep), plastic juice bottles for mixed chem’s, a thermometer my dad left in the workshop from the 70’s of questionable accuracy and normally don’t even use rubber gloves – I try not get my hands in it. The only one that’s really a concern is the blix staining but there’s always wash water available if you’re worried about irritation. I just make a small vacuum with the lid and hand roll my Patterson tank once in awhile, never need the agitator. The results have been great. I don’t know if it’s because I’ve never learned to do it properly (and I never take written instructions seriously) or too many people in YouTube land passing themselves as experts have made such a big deal of technical accuracy that it’s considered law now but it’s simple and forgiving enough, I’d encourage everyone to try it and not be afraid to fly by the seat of their pants to gain experience. Looking at a slide (particularly 120) fresh out of the final rinse is something every ‘tog needs to see,

      1. Relax and have fun… and try stuff! My instructions said the first rinse cycle in warm water for 60s and don’t agitate. Vid’s I’ve watched stress the importance of using a stop watch and no agitation so as not to wash away the color. When I saw the cloudy water come out of the guys tank, I said: screw that, the loose emulsion will just burn up developer so on my first roll I washed it 4 or 5 times with heavy shaking in between wondering if it would wash away my color. It didn’t, came out perfect. Crappy pic but you can see the color:

        The best thing about developing film is happy accidents… unhappy accidents are part of the process and need to be embraced.

        1. Thanks Kevin, I see your point. I’m happy with the results I just didn’t enjoy the process for me. Really enjoy black and white development though so I think I’ll stick with that for the most part ????

    1. Must say that I agree Kevin – when I first got into processing C41 film I was using a thermometer that turned out to be five degrees out and I got useable results. I have to say that since I got an accurate thermometer the useable results have been more conistent and probably a bit better, but I still heat the chemistry in a water bath in a washing up bowl and I’m sure the temperatures fluctuate more than they’re supposed to. But the quality is fine.

  7. If you search online you can find 3D printer plans for new agitators for the Patterson tanks. However they MUST be printed with ABS plastic, not the other kinds.

  8. Great article – I did color slides years ago without benefit of the souls vide. The results were good, but as you quite rightly note, the process was so finicky that I abandoned the whole thing after one kit. Easier just to send the slides away for my rare ventures into color. Long live black and white!

  9. Well done on getting useable results from hand developing E6, moreso from a roll of Ektachrome. In a previous life I used to work in a high street minilab and it was muggins who was tasked to develop the B&W and E6 in a Jobo motorised drum developer. I hated that poxy machine, I’m sure it was the offspring from an illicit union between a 1970’s Indesit washing machine and coffee maker. First part of the developing procedure of a batch of slide films was to stick the kettle on, not for a cup of tea but for the water bath the drum needed to slosh around in. The level of the bath had to prefectly correct. Not enough bath water and the film didn’t develop correctly, too much and the drum floated off the roller mechanism. Then there was the film. Fuji and Agfa? No worries, came out perfectly developed every time whatever the weather (yep, atmospherics had a hand in it too, the room the machine was set up in was unheated.) Kodak film? Nah, forget it. Thick, dense slides were the usual result. Add to the fact that we were pushed to upsell Kodak film over the others. I died a little inside when I sold 5 rolls to someone, who I knew would bring them back after he’d spent three weeks Yak trekking through the Amazon. Or at least I think he had, since the resulting slides were so sodding dark.
    So in a non-condescending way: Well done on the resuilts you got, and thanks for bringing back painful memories that I had repressed for 3 decades. If anyone needs me, I’m off to spend the rest of the day sobbing quietly curled up in a foetal position in the cupboard under the stairs.

  10. Great article,Laura. Precisely why I stick with B&W. I rarely do colour but,when I do,it gets sent to the lab as I don’t need that level of aggro in my life.

  11. I’m a film photographer and I’ve been using slide film for years. I love the look of it, but I’m not sure I could ever get used to the process. This blog post is a great introduction to the process and I

    1. Thanks for this. I must admit after doing it a few times now Im also not sure I am into it enough to keep doing it. My issue is access to professional development is none existent so it’s either do it myself or risk shipping films abroad. I am also finding that I need a few rolls to make it wroth while so I end up leaving films undeveloped for some time then hate the process of developing so many at once 😂. It’s definitely a chore either way 😂

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