Category Archives: Kodak

Portra 400 Reciprocity Failure

Normal Reciprocity

Normal reciprocity is when your camera settings are balanced to allow light entering the lens to hit the light sensitive film evenly thus creating an image that is correctly exposed with no muddy shadows, high grain or blown out highlights – if you’re using colour film this will include no colour shift or colour cast.

So exposure settings of 1/60 at f/11 will give the same amount of light as 1/125 at f/8 as 1/250 at f/5.6. Remember to take in to consideration changing your aperture will affect depth of field and sharpness so if you are shooting at f/16 you’ll need to compensate using your shutter speed alone but hopefully from this example you’ll understand…

What is Reciprocity Failure?

Reciprocity Failure is when your camera settings aren’t balanced which results in an incorrect amount of light hitting the light sensitive film for an incorrect duration of time. So If you’re unable to adjust your camera settings to compensate this will cause reciprocity failure. Failure can also occur when an ND filter is used and the incorrect meter reading / exposure settings are set.

The cut off point for each film type varies but there’s a reciprocity failure point for all film types – for black and white film this results in less dense images with increased grain, muddy shadows and blown out highlights. To compensate for this you will need to extend the exposure time and pull the processing time so highlights aren’t blown out but detail is retained in the shadows. Colour film requires similar time and processing adjustments to B&W but with the added bonus of colour shift. This can be corrected during post by adding more saturation and colour adjustments.

Interestingly reciprocity failure doesn’t occur in digital cameras – this is because light hits the sensor and is recorded in the camera whereas light can scatter and bleed into other layers on sensitive film. However a side effect of long exposures using digital is increased noise.

There are plenty of people who’ve taken the time to study different film stocks over the years and measure reciprocity. I used this graph by Isaac Sachs to reference Kodak Portra 160 & 400 to calculate how much time I would need to extend my exposures.

For Portra 400 reciprocity failure starts around 4s which would result in a 0.5x increase in exposure time. For those who want to see some results of over and under exposing Portra watch this video by Kyle McDougall.

The Shoot

This was a simple test shoot of 10 frames just to give me a baseline for future experimentation and to see what mistakes I make now so I can make informed decisions on a future project.

Firstly I should’ve shot a lot more, like the entire roll more! Secondly the changes in colour shift aren’t nearly as dramatic as I was expecting. Frame 6 (bus stop) is too bright from what I wanted. I love that the shady bushes behind have retained detail but the moodiness and amber light that was cast over the road has been lost. I could fix this in post – but showing accurate test results is what i’m presenting here – not a prize winning photo. Thirdly I should’ve experimented with longer exposures (20, 30s + etc) in darker areas using a cable release to really stretch the film and experiment with the same subject using different settings to set a baseline for reference.

Metering was taken using the camera internal ETTL as well as a Light Meter app. I used Tetenal C41 developer using the standard development time of 3m 15s at 38ºc. I did not pull the process. Full Tetenal development details can be found here

Frame 1

Frame 2

Frame 3

Frame 4 – feels too bright and saturated compared to the rest of the test

Frame 5 – I actually like the tones in this shot. Muted yet amber of the lighting nearby. Could do with a punch of saturation.

Frame 6 – getting washed out. Good shadow detail but lost amber glow and ambience of the environment. Too bright

Frame 7 – shifting towards yellow

Frame 8 – deeper reds

Frame 9 – more red tones

Frame 10 – shifting towards green

 

Have I missed anything out?

If you think I have missed something out or not give the correct credits please let me know on Twitter or the comments box below.

Resources

What is Reciprocity Failure?

Long Exposure Film Tests

Reciprocity Graph Portra 400

Ilford Low Intensity Reciprocity Failure

I Still Shoot Film Reciprocity Failure

Geoff Lawrence Reciprocity Failure

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Kodak Portra 400

Brad sitting at the Wetland Centre. Photo credit: James Wakelin

A Fresh Start

The first roll of colour film I developed at home for this blog was Lomography Colour 100 with Tetenal C-41. The results were pretty good and I wondered why friends in the photography community always claimed colour was more tricky…I agree one must be very precise with water temperature during processing but as long as you set up a good workflow you minimise risk of problems.

At the beginning a rookie mistake I made was storing chemicals in glass bottles on the top shelf of my wardrobe instead of plastic bottles on the bottom shelf. Unfortunately the shelf gave out from the weight which smashed everything on the floor…whoops! More about that can be read here.

Another mistake I made was not knowing colour chemicals do not stay fresh for very long once mixed (6 weeks), the concentrate gives you 12 weeks though, added to the 6 weeks after mixing is another 24 weeks. I tried mixing another 1000ml after the end use date and the bleach fix turned into a yellow lumpy cheese like goop. Not good.

Tetenal can process around 30-40 rolls of film so these two mistakes are an expensive lesson to learn. At the time I didn’t have the money or free time to invest in 40 rolls of film to shoot – I was looking for a new job and had a lot of changes happening in life.

I regularly wrap paper around my film telling me what is on the roll for a later date when i process.

Fast forward to Autumn 2019 and in 3 months i’ve shot 20 rolls of film to develop and will be ordering some more for a short trip away in October – so fingers crossed I should hit that 30-40 number making things way more cost efficient.

Mixing Tetenal C41 developer.

How I develop

Follow the instructions in the Tetenal guide – they’re fool proof and super easy! Each time I develop a roll of film I tally up the guide to track the life of each mix. The development and bleach times are extended depending on how many rolls you have developed or if you are push processing.

Everyones workflow will vary but i’ve found that if I fill a bowl with water to around 50ºc the heat transfer warms up the chemicals with enough time during cooling to 38ºc to load the film to the spools & development tank. Once the bowl temperature reaches 39ºc I start a 5 minute film bath at 38ºc (water taken straight from tap and temp measured using thermometer). By the time I have finished preheating the film the temperature in the bowl and my chemicals are 38ºc exactly.

I always put the development tank in to the bowl to keep the temperature up and I regularly check with a thermometer! If it starts dropping below 38ºc I top up the warm bath with hot water to a couple of degrees higher to keep the chemicals at 38ºc.

Scanning:

Once the negatives have dried they are cut in to a strips of 6 frames and placed in an archival box. I use industry standard archiving from when I was working as a retoucher – date backwards, followed by job number, then by product, and client or location. Underscores are used instead of spacing. So the latest project is always at the bottom of the list. For example the roll of film for this blog post is 19090601_KODAK_PORTRA_400_LONDON_WETLAND_CENTRE

The job number goes up depending on how many jobs I have that day. This is handy if i’m with the same client but on a different shoot or location or batch. I.e 19060101_PORTRA, 19060102_PORTRA, 19060103_PORTRA, etc etc etc

I scan my negatives flat without adjustments or sharpening using a Plustek Opticfilm 8100 at 3600 dpi which produces a 50mb file at 3300 x 4968. The scanner can do up to 7200dpi however the scan time is too slow and I don’t require that much data for web use. If I ever print the images I would rescan at 7200dpi and reprocess for print. The images are saved as PSD’s which increases their compatibility with Lightroom and Photoshop. Lightroom is my main tool for global adjustments such as colour, cropping and batch processing. Macro adjustments and cleaning are done in Photoshop.

London Wetland Centre

This roll of Kodak Portra 400 has been processed with warmer tone that I feel reflects the warmth of the summer day I shot it on.

Limehouse to Camden Canal Walk

Lewisham twilight

These photographs are some test shots I took for a future post about Reciprocity Failure.

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Found Archive: Kodak Gold 100

Being so young at the time these were taken I do not know some of the people in these photographs. However they were taken in a small town called Brightlingsea on the Essex Coast during the 1980s. These photos are of my Aunts, Sister, Mother, Great Grandmother and Cousin – oh and the happy baby is me!

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Found Archive: Kodak Gold 200

This collection of photographs is from the year 1989 along the Norfolk Broads.

Kodak 400TX (TRI-X)

The Kodak Tri-X is the first but not last roll of film that i personally developed for this project and it was a pleasure!

My early years of photography were spent in the darkroom learning to develop and print film and ‘retouch’ photographs using various techniques, unfortunately this practice was short lived as i quickly migrated to Digital because of its speed, ease and cost effectiveness.

I had always missed being in the darkroom though so decided for this project that i must start developing my own film again to fully appreciate shooting in 35mm and to please myself in the process.

I shot a roll of Tri-X and booked a brief induction to the darkroom as well as a refresher course on developing film, of course i hadn’t forgotten the process of developing however it had been almost 7 years since i developed my last roll of film so i had to make sure that i didn’t leave anything out.

I met a guy called Dave and there was 2 other people on the refresher evening, one of them i knew, Mike, who works at the Camera Club. Dave is insanely knowledgable and deeply enthusiastic about film photography, perfect! We got chatting and he guided us through the developing process, mixing solutions and the various techniques and tools available when developing film.

After this we each went into our own darkroom, shut the doors, mixed the chemicals, turned out the lights and started spooling! Fantastic! It’s like riding a bike.

Chemical process: Rodinal at 1/25 solution for 300ml 7 minute develop (12ml Rodinal topped up to 300ml water). Agitate for 30’s then tap, leave 30s, agitate twice, tap, repeat agitate every 30s.

Empty developer, rinse for about a minute then Fix with Ilford Hypam. Agitate 30s on, 30s off. All solutions at 20 degrees c. Empty and dilute with water for 15 min, didn’t use stop bath.  Note: Kodak state that you can stand tri-x with little agitation and high developer concentration, using this technique you can push the film to 3200 and beyond, this is something i will be doing in future.

I chose 7 minutes as this was the recommended time by Rodinal for Tri-X. I could also double the time for a slower develop however i wasn’t worried with that this time, in the future i will alter development times depending on the results i want from the grain. So faster develop will make the Silver Halide clump together to produce bigger grain, slower develop will have finer grain.

Film was clear after 3 mins so to permanently fix i leave for another 3 minutes. The reason for this is that film is opaque to stop light bouncing around inside the camera when you take a photo and causing the photo to expose incorrectly, fixing removes the opaque look as well as fixing the image to the film, once the film is clear during fixing make a note of that time then continue to fix again for that time duration (so 3 mins to clear, fix for another 3) this will mean that the film will stay constantly fixed and will last hundreds of years. Rather than going 20 years down the line and it becoming faded or coloured because it wasn’t fixed properly.

Once film was fixed i used some Photo Flow which helps alleviate drying marks then removed the film from the spool and hung to dry in the drying cupboard. 15 minutes later 1 perfectly developed film.

A great website for getting film development times is www.digitaltruth.com

Scanning results where fantastic, there was minimal dust and scratches on the film and the overall quality seems much better than when i have used lab’s to develop. I am tentative to speculate as to why there were minimal dust and scratches, i could of just been very lucky and the film emulsion was perfect however the past Lab results  scratches are too frequent, a part of me thinks that they’re not as careful as i would expect them to be. Suffice to say i will be developing all of my film myself from now on.

Shot on Canon EOS 620 with 24-70mm 2.8 USM L Mk II lens. I am very happy with the results of this process, the highlights have details in them and the shadows are strong, the grain desirable and consistent.

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Kodak Portra 800 Pushed to 1600

This is the final roll of a series of four types of film shot over London Pride 2013, please take a moment to look back at the other type’s previously posted: Kodak BW400CN, AgfaPhoto APX 100 & Kodak Ektar 100

By the time i had loaded the Portra into my camera it was getting well into the evening and as the sun was going down the alcohol content in my body was going up so its no surprise that even though i remember shooting this film there are a couple of shots that i looked at when scanning and thought “I don’t remember shooting that” and felt excited to see them appear on the screen.

I decided to push the Portra at the very last second and i’m glad i did! Albeit only a 1 stop push from the original 800iso i didn’t want to go too crazy as i hadn’t seen Portra pushed before so felt it best to take it 1 stop at a time. I’m glad i did.

I like Portra, i think its a great film to shoot with, it has some great neutral tones to work with and the slightly desaturated results seem to work well in evening light adding to the authenticity of being shot in the evening. The push in my opinion has improved this film considerably.

The results from this push are a high grain that is very appealing to the eye, especially of the young woman outside Wok to Walk with a folk in her mouth. The push has given a similar look to some old 70’s colour film which had a tendency to look more grainy (depending on film type). I had to remove quite a bit of green colour cast from the photos during cleaning – i have mixed opinions as to why this happened. It could be an error in processing where they’re using too much of a colour which will leave more green in the photo or it could be an error in scanning and the CCR (colour correction removal) process.

Also dust and scratches was a little extreme with this roll of film. Typically i have noticed that colour films require a lot more work than black and white, especially Kodak compared to Agfa or Ilford.

Due to the high grain and desaturated images the landscapes that i shot of the wind turbines and power lines aren’t really suited to this film type.

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Kodak BW400CN

This is the third post in a series of four rolls of film shot over London Pride 2013. Please take the time to look back through the previous post’s to fully appreciate the event and various film types used throughout the course of the evening.

The previous posts are Kodak Ektar 100 and AgfaPhoto APX 100

By this point in the evening i was getting quite drunk, i had great friends around me and the streets were alive with thousands of people celebrating Pride. The city had an energy surging through it. It was exciting to scan and see the results of the 400CN as i couldn’t remember some of the shots i had taken (oh dear).

This film delivers excellent deep contrasts and tones with a very desirable fine grain considering the ISO. Skin has come out clear and the highlights are giving a gorgeous glow.

I will shoot the next roll pushed as i am eager to see the results first hand as i feel it will not be able to handle a massive push due to it already being quite a contrasty look, however i could be wrong as processing will play an important factor.

Leading me on to some important news! I have signed up for Kennington Camera Club, which is only a stone’s throw away from me. I can now use the studio for larger shoots and i will also be using their darkroom to develop my own film.

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