Re: Color management

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



I thought I was alone with my take on colour management but it seems others have 'discovered' the same thing as I.

I'd also state straight up that I taught photography as a science course, so the emphasis was not on following what I say, but in having students TEST what I say - compare it to other methods, compare it to 'what they know' and evaluate the results as objectively as possible. That is what science is.. degrees don't make a scientist - science is a philosophy of analysis.


So firstly... if you're a graphic designer working with colourmetrics, you've a set of colours that are limited to your printer, and graphics printers are generally 4 colour.

This means: photographs will never reproduce well
Your calibration is based on inksets used in specific printers.
You will pay dearly to buy profiles.
You will be outputting to a very tiny selection of printers.
Photographers will hate your work and say you do not understand colour.


We are photographers. We work with many more inks than this, we don't like spending money, and we DO understand colour, just differently than graphics guys understand it.

I was thinking about this one day while I was running a control strip through the RA4 machine. For those who are unaware of the process, a batch of 'control strips' are bought from Kodak, Fuji or elsewhere that are simply lengths of RA4 paper, frozen, that have been exposed to give a selection of colour swatches. Instructions on the box include (specific to each batch) standard colour correction variables - ie, each batch of paper is different so even though the exposure of the paper was done under a specific, carefully monitored light source, the paper will not represent these colours 100% accurate from batch to batch.

Running these through the RA4 machine each day you'd then pop the control strip under a densitometer and check how close the colours were to what they were supposed to be (allowing for the included variation) then you'd head back to the RA4 machine and tweak the chemistry..

This was a number of days after Fuji Australia had failed to reorder E6 control strips and we'd run out.. 4 weeks wait and we neeeeeed these things to get the chemistry right! Kodak had none either (unbefreakingleavable)

I got around this pretty easily by grabbing a batch of frozen film which had always produced reliable colours, then I shot a few rolls of a Gretag card under controlled lights (flash with voltage monitoring) at a specified distance at a specified exposure with a specific camera. - all carefully noted in case I needed to go through the process again at a later time. It is critical you use exactly the same setup, any variations *here* will affect stuff *there* - how you going to know which was which?

After this, I snipped off a few frames and ran these with the last control strip through the chemistry. Popping them under the densitometer, I calibrated the control strip, then adjusted the values against the stock I shot.. I calculated what the correct values for my control strips were, adjusted the chemistry based on the last Fuji control strip then checked mine again. Pretty close to perfect.

Noting the various values for My Control Strips, the rest of the rolls shot were snipped up and frozen to be used daily.. When the Fuji control strips finally came in I checked the chemistry as we'd been using it against what it was supposed to be and it was as though we'd been using the Fuji's all along.

Back to the RA4 saga..

I was tossing all this around in my head along with what I knew was being taught about colour management to students and I had a bit of an epiphany

Firstly, aside from the control strips, NO ONE sticks their prints under the densitometer unless they're testing papers! No final print is ever checked this way - they're viewed under a controlled 'daylight' light source by eye, but never a densitometer! We only calibrate the 'printer' - not the film, not the lighting conditions, nothing but the printer (RA4) and then as we print we eyeball the results and tweak the filtration until we get the print looking right. Once your light is right, for that entire roll of film (if the subjects were shot under the same light) no further tweaking is necessary.

Sure we may filter light when shooting, and we may select specific film stocks, but these are always to get 'best looking' results, not '100% accurate' results (impossible anyway). Who filtered to eliminate the sky colour in the evening? No one. Unless you were shooting for colour accuracy, in which case you'd have been better off shooting in a studio.. even then, your film stock would let you down. Remember how we picked Kodak for reds, Fuji for greens etc? What did accuracy have to do with it?? The closest film to accurate was Konica 100 and no one used that (that's an objective analysis done by a compulsive film tester who blew loads of cash testing every film available on the market talking ;)

Ultimately, we went for what LOOKED right.

Anyone who took a leaf and compared the leaf it's self to the print under a densitometer deserved to be dragged off to Trembling Willows and placed in a room with rubber wallpaper. We photographers unlike graphics folk, go for what *looks* right. The managing director of advertising at Coke doesn't care if the logo looks green under fluro lights, what he cares about is that the logo looks exactly the same - exactly - as the pantone swatch value for his logo colour under the same lightsource, so all coke logos, coke labels and coke party hats .

We came to digital imaging as photographers long after the graphics guys did and we adopted their tools - which was all there was - and we basically copied their techniques without ever asking if it was the right way.. after all there was a huge learning curve and the graphics guys seemed to have it nailed. but the fundamental philosophic difference was overlooked..

This set me to work trying to find a more appropriate method of colour management for photographers than that we were using. I was mixing with graphics and printer guys not long after this at a Canon printer repair/setup training course and I mentioned I was on this path - I was soundly congratulated by all and sundry as (in their words) they were heartily sick of photographers and how little they understood of colour. (/hangs head in shame) The individuals who created all on Ilford Australia's colour profiles were there, the biggest distributor of wide format printers were there.. they all said the same thing.

The thing was, once I nailed it I didn't actually have anything saleable for anyone, it's actually very easy.


First thing to understand is printers, as these are often the intended final output device for photos. More on screen colour later..

dpi means nothing, ppi means everything.. and printer manufacturers confuse the two to confuse you. DPI is how many splats of ink per inch the printer may use to make up a colour. Tamper with this value by restricting the number of colours the printer can select and you'll lose your colour range. Canon doesn't let you near this value (nor should they) Epson does. Great for Graphics folks to limit their colour range, a disaster for photographers. leave this alone.

Media. Basically there's gloss (needs more ink squirted per drop), matte (needs lots more ink squirted per drop) and plain (doesn't need much). All changing the media should do is change the amount squirted out per drop. Canon and almost everyone else abides by this simple rule, Epson does not. Don't believe me? Change the media setting and run three prints through on the same media, the colours will look pretty much the same out of a canon, just more or less (paler or ink sloshing across the paper). Do it with an Epson and watch the colours actually change. Epson like photographers. Epson sells many, many profiles to photographers. Photographers love Epson. Epson is a wealthy company. (Epson is Seiko)

Quality.  Draft (skip some lines (low dpi), make tiny drops, go fast).
Standard (don't be too fussy, put a reasonable amount of ink down, use maybe a few more colours and quirts) Graphics ( let the rip go stupid on saturating the more perceptually 'vivid' colours, use lots of ink, avoid subtle tones please RIP) Photographic (ok guys, fire up the 'good' rip, be careful with colours, lay down reasonably heavy drops (check the 'media type') and use all the dots you need to get the colours goodest)


Photographers should have their printers set to photographic quality, gloss or matte and nothing else.

Set the PPI on the image before sending it to print and get it to bang on 300ppi for the intended image size. If using an Epson and you go looking at dpi, set it to maximum, but restrict the print size to whatever it is you intend, ie an 8x10 image should be sent through as 2400x3000 pixels, image size 8x10, dpi= max. do not send 4000ppi images to print or your printer will hate you..


Now the colour side of things..  this bit is actually short.

I made a swatch of colours, RGBYMC and a greyscale, including a headshot of a person under 'natural daylight' on 'normal' camera settings and bunged these together as a 'Shirley' and sent it to print, setting the media to gloss generic, photo quality.

Look at the result under a decent light. Is it too red? go back into the printer settings and change the 'gloss generic' setting and dial back the red. Was it too pale (not enough ink)?, increase the saturation. Tweak away and save it.

Note: Some may view this a laborious and costly exercise, but potholes in the road cannot be filled in with by the Transport Minister simply sending an email - someone still needs to pick up a shovel. Same same as thinking you can calibrate without using any ink.. sorry.

Once you're happy with the result, save it.  Repeat with the matte paper.

(Now I know that with Epsons if I do this, it works, irrespective of the paper brand - the images will all look the same. However if I tell the Epson I'm using Iford paper for one print and Fuji for the next, the colours will be wildly different. Why do you do that Epson - it's crazy! If we go popping in the brand and style for each paper type on an Epson, we'd have to calibrate each one.. total madness.. but a good way for Epson to sell profiles! Epson really got to annoying me..)

Next, grab one of your unaltered digicam images at random , using these print settings above, send it to print. Sit back and be amazed at how good the image looks.

I've had people who have every calibration device known to man, every software calibration tool loaded and follow meticulously all the chants and arm gestures. They've risked everything and tried this method only to discover all their past image adjustment was simply fighting both ends of the snake. Consider: you calibrate a profile for importing pics, you alter the way it looks by having a monitor profile 'adjust' the image to look good, you have another calibration profile adjusting the printer.. now, should one go wrong - which is it? Could it be they're all adjusting each other to give you what you had in the first place? (and that's not even going anywhere near the 'hidden' profiling done by the OS, browsers and graphics cards)

Next step is to shut down ALL image tampering your PC/Unix/Mac/Other does and calibrate the screen - use software or the monitor hardware, no one cares.. but make the screen match the print as closely as possible.

Looks pretty OK, hey?  <glares balefully at the Eye-One>

Don't fret that your monitor is now 'off'. Odds are that 90% of the folks viewing your images on the web do not have their monitor calibrated and even if they do it'll still not look anything like yours. Different phosphors, video cards, Shell enhancements, browsers - they all impact colour. If it looks OK to your eyes, it's OK.

That's it.

If you plan on using Joe Bloggs Printing Services to have Pegasys prints made, no bother - make an 8x10 filled with 4x5 rows of those shirleys on the same page, but tweek each to create a colour ring (0 correction, +5 Red, +5Red+5Blue, etc) Flatten it and save as a jpg 100%. When you first send these guys a digital file, make it this one - check the print when it comes back - if say the +10Green+5Blue looks best, before you send these guys your images to print batch apply these colour adjustments to your files and send them off - you've just applied a profile to their printer :)


There is no dark art to this, no hardware required, just a set of eyes and a change of thinking. Try it and see.. Mind you, I don't know your PC or printer so I couldn't advise what may complicate things or what may fight you - it's no different from talking to 'that' person via email who has to upload every attachment he wants to send you to an online fileserver 'coz he somehow can't send attachments with his email program. How the heck do I know what software has fouled things up? All I know is all the students who tried this stopped pratting about with the other methods and whizzed through their work with less stress and more success, and wondered why they'd ever bothered with all that graphic design nonsense in the first place. Their work was noticeably better and colours looked much more natural.

A final word on OS's, browsers and video cards. A lot of modern OS's employ tweaks to 'correct' colours and smooth jaggies - I don't like this. 3D graphics cards do the same, often sacrificing colour accuracy for high frame rates - I don't like this either. Then the new Safari browser as I've said before, employs some clever algorithms to tidy up images and make them look nice for the viewer - yeah, not happy with that too. When I am tampering with images I want to see all the warts, I do not want the gamma being corrected and the tones smoothed - I NEED to see the faults to correct them. Apparently I am also blessed with Very Good Eyes so I *can* see problems and I do not like it when they're being hidden, especially when I'm trying to make the best images I can.

It's no different than were I doing audio editing while my audio card decided I should have '3D effects' turned on whilst using a Cathedral profile to make it sound awesome. The first time I hear my efforts reproduced on another machine without these enhancements (impediments) I'd hang my head in shame and wonder how I could have shared such a ghastly audio track with the world.

Most folk don't realize their computers are doing this, wouldn't even know how to check to see if it were the case.. but that's not how it should be. Anyone working as a pro should know precisely what gear they're using and how it's being used. it's kinda part of the job description.. but no shame to those who are unaware - that's what asking is all about, trying to find out what is what and working with new information.


Like I said at the get go, this effort is cheap and requires no purchase, It only involved people giving it a go and seeing for themselves. Other photographers have also found their way to this method all by themselves which heartened me as I read of more and more people 'discovering' this way - it showed they too were meeting success and had also followed a similar logical path. Anyone can try it and if they don't like it they can ignore it and buy someone elses hardware, books, training courses etc.

it's an alternative method - might be what you want, might be worth exploring.. up to you ;)

hope it helps someone

k
















[Index of Archives] [Share Photos] [Epson Inkjet] [Scanner List] [Gimp Users] [Gimp for Windows]

  Powered by Linux