Hi,
Having read the whole thread, let me try to give some answers / background information:
Prints from Photo labs:
Most, if not all, labs print using the sRGB colour space.
Main reason: convenience and reasonably good print quality.
Labs generally will not convert to any output profile by using Photoshop. The printer (like the Fuji Frontier) will do this automatically, it has a 'sRGB print channel'.
So, therefore it is best (and recomended by the labs themselves) to supply your images in the sRGB colour space.
I think Chuck made some very similar comments regarding sRGB...
Colour Gamut of D7(H)i:
I made custom ICC profiles for my Dimage 7i, which clearly indicate that the sensor is capturing colours to a far bigger extend than sRGB colour space.
Also, many colours are corrected, some to a large extend, by assigning this profile (in particular there's a sigificant reduction of magenta/red, making skies more blue, purple flowers less red, and so on).
By the way, the colour capturing (obviously!) has nothing to do with subsequent RAW or JPEG saving.
Colour gamut of photo paper (conventional chemical based):
Although there are some differences in the ability to reproduce colours by different types of photo paper, in general most papers will not be able to reproduce colours outside of the sRGB colour space. There are some exceptions, but mainly in the very dark colours.
For such photographic papers, it is not necessary and actually unwanted for the to-be-printed image to have wider colour gamut than sRGB.
-> Note that is still usefull to assign a custom, dedicated D7i profile before converting to sRGB to 'fix some colours'.
Colour gamut of inkjet printers:
Several inkjet printers, including my ageing HP720C can reproduce colours outside of the sRGB colour space, mainly in the bright red and green department. The technical reason is that the inks are more pure (measurable by spectral absorbance) than the dyes from the conventional photo paper.
In this case it is wise to (again after assigning the proper input profile) convert to the ouput profile of the printer, should this be available. Note that Colour Management should be off in the printer driver in order to avoid double colour space conversions (i.e. bad results).
Summing up, I have to agree with Chuck:
- If you're not familiar with colour management just use a sRGB workflow (do not convert your D7i JPEG's as they are already in sRGB colour space, just send them to the lab or print at your own inkjet using sRGB).
- On the other hand, if you are a fanatic (like me) and want to get the best results, do this:
First, create proper ICC profiles for your camera and printer (in my case also the Fuji Frontier digital minilab). If you can't do that, you could ask me for some advice / profiles
Output profiles for inkjets may usually also be obtained from the manufacturers website. These ICC profiles however are very generic, and may not be suitable for your printer / paper / driver settings combination. Home made dedicated ICC profiles will always perform better.
After this first, but most important step, follow this workflow:
Assign you custom camera profile to your D7(H)i image (you could use sRGB, but as stated above it is
not the best).
Then, convert to your printers output profile. At this point you also should have a good preview on your monitor of the actual print results (
if your monitor was properly calibrated and profiled).
Finally, just print your image, making sure all colour management options are set to 'off' in the printer driver.
This workflow will give you the most authentic colours, yet at some labour cost...
BTW, I developed some dedicated software which can batch transform images automatically to avoid using Photoshop altogether.
I hope this post may give some answers to your questions / remarks.
Greetings,
Auke Nauta
