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Calibrating cameras/lenses etc
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Hi folks,
I’ve just been through a 2 day exercise calibrating my new camera (D3) and lenses for CA correction and colour.
Is it worth doing, well, I’d say necessary if you’re shootng products (think of the money spent on choosing those colours on a label). The good thing, apart from one of the cheapo lenses I still use, the rest needed hardly any CA correction (I was zoomed in to 400% to make the changes, so you could hardly see it at full-size).I was wondering how many of you bother with system calibration, lens, camera,screen,printer etc?
If anyone is interestd in the calibrations for colour on a D3, give me a shout. I won’t bore you with them here. For the people that knock Photoshop/lightroom/ACR compared to the manufacturers converters, it was a lot closer to accurate colours than the Nikon software (has a tendency to make reds, orange) and it’s closer than DPP (tends to make skintones red), and definitely better than Fuji (which has the nicest looking colours of the bunch, but also the most inaccurate).
Next time I shoot colour film, I shall shoot a test target just to see how close it is to accurate!! :) Just think Velvia and accurate in the same sentence :)
Si
I don’t bother calibrating my camera and lenses – it might be worth doing for CA (assuming you’re using lenses that suffer overtly from it in the first place), but unless you’re doing product photography it’s of doubtful usefulness – certainly it won’t hurt to do it, but I’d question if it was worth the effort.
On the other hand calibrating your screen is an absolute must if you’re doing image editing of any sort. You’re just spinning your wheels if you don’t invest in a colorimeter and accompanying software, and your prints will be unpredictable.
For those that don’t know, calibration of your screen is necessary to get it to display accurate colour and tone. All monitors are different (think a TV shop where all the TVs are showing the same program, but vary wildly in brightness, saturation and contrast). This difference must be accounted for before you start editing to get a predictable print.
A colorimeter is a device which sits in front of your display and reads colour and tone information from the accompanying software. The software knows what colour/tone it output, and the colorimeter reports what the monitor actually displayed. This is done for 70 or 80 different swatches and the resulting profile is then saved to your operating system.
Now, when a program wants to display something to the screen, the OS checks the profile and applies the relevant correction to ensure that the monitor displays the right colour and tone.
Now, when you make your edits you know that you’re starting from the correct point, and your prints will look much closer to the displayed image on the screen.
Printer calibration is also important, but there are canned profiles available from the printer/paper manufacturers which get you close enough for most purposes. If you want something more accurate, you can pay someone to profile your printer/paper for you – or you can invest the couple of grand to get yourself a spectrophotometer (does the same thing the much cheaper colorimeter does for your monitor, but does it on your printer/paper combination instead).
Cheers,
PeterI think we’ve just agreed with each other Peter. Product photography and anythng where brand colours are important would be the only thing it would be necessary for. HOwever, there is a clear difference pre and post colour calibration and I like working to a known start point. What’s the point of having thousands of quid worth of gear and not setting it up well?
Re paper/ink/printer combinations, I haven’t ever found a canned profile acceptable but most paper manufacturers will let you print a test pattern and then calibrate it for you. Or you can send off a test print and get a calibration for arpound 50 quid. Well worth doing IMO.
Screen calibration is a must for me.
Si
Thanks guys, both very helpful, but I was just wondering how you calibrated the camera itself, as it implies in the first post?
johnnycivic66 wrote:
Thanks guys, both very helpful, but I was just wondering how you calibrated the camera itself, as it implies in the first post?
Hi Johnny,
It’s about calibrating the colours, rather than the tones, although you can do both.
Go here, for a downloadable scrip-t to run in Photoshop that will calibrate the colours for you against a gretag card.
http://21stcenturyshoebox.com/tools/ACRcalibrator.htmlIf you want to calibrate the greyscale patches, you can do that too. YOu still need a good white balance.
Si
Si, I’m just curious as to whether or not you created a separate profile for each of your lenses and whether you used studio flash or”daylight” to do this?
Thorsten wrote:
Si, I’m just curious as to whether or not you created a separate profile for each of your lenses and whether you used studio flash or”daylight” to do this?
Hi Thor, how’s life?
I used 4 different lighting conditions and my 24-70 lens at different focal lengths and apertures. I have a set of numbers which work well for all focal lengths and apertures in any “Daylight” conditions (so studio flash and on-camera flash included). It falls down under “weird” lighting, like pure blue shadows and low power incandescents. Haven’t tried it under flourescents yet.
With my D2x, I did it for all lenses and found that the Sigma settings were slightly different from the Nikon lenses. Similar on the 5D with “L” versus” cheap rubbish kit lenses.
I’m not bothered about absolute perfection, just accurate enough. If I do a product shoot, I’ll include a gretag card anyway under fixed lighting. The defaults I use are for the lens under daylight. (In summary). And well worth doing.
On the 5D, for instance, the tone curve, has a very steep fall to black (almost a step), which can be ironed out and the reds aren’t right to my eye. (It’s the yellows on the Nikon, so each brand must have it’s subjective colour balance choices).
With respect to CA, the 24-70 only really shows it at 24mm and f2.8, otherwise it’s hardly worth changing; I did calibrate it at the standard focal lengths; 24,28,35,50 etc. I do have these set as presets for F5.6 and below for when I know the shot is going to be blown up big and need corner to corner sharpness, otherwise I don’t bother.
All best
Si
Hmm, must have a serious look at doing this myself at some stage. To my mind, Canon images have always had a strong red bias and one way I was thinking of tackling that was creating my own Custom Picture Style (using Canon’s Picture Style Editor) or permanently entering a white balance compensation in the camera. Whilst I have come across Thomas Fors’ ACR Calibrator before, I’ve never done anything with it as I don’t use ACR for my RAW conversions. I have used Magne Nilsens custom camera profiles in conjunction with Capture One and if there was some way I could create my own custom ICC profile without going to enormous expense for a once of profile, that’s what I would do.
Thorsten wrote:
Hmm, must have a serious look at doing this myself at some stage. To my mind, Canon images have always had a strong red bias and one way I was thinking of tackling that was creating my own Custom Picture Style (using Canon’s Picture Style Editor) or permanently entering a white balance compensation in the camera. Whilst I have come across Thomas Fors’ ACR Calibrator before, I’ve never done anything with it as I don’t use ACR for my RAW conversions. I have used Magne Nilsens custom camera profiles in conjunction with Capture One and if there was some way I could create my own custom ICC profile without going to enormous expense for a once of profile, that’s what I would do.
Simon Tindemans script reads all the gretag patches and allows you to “Weight” them for accuracy and importance. I have the skin tohe patches weighted highest.
http://21stcenturyshoebox.com/tools/ACRcalibrator.html
Si
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