Ethan, why should I use printer profile?

[vietnam photo]

Ethan, per DryCreekPhoto website, before we send in photos to

printshops at Costco, we should convert our photo using the profile of

the printer at that Costco store. My question is if my monitor is

properly calibrated, say with tools like Monaco XR or Gretag, why

should we still go to this step. Why can't the printshop accept our

jpg as-is and do the conversion for us? Is it a cost issue or is it an

accuracy issue, i.e., it is best that the photographer do the

conversion to ensure proper matching between color spaces of

printer/paper and his monitor? Thanks a lot for you answer. My

brothers and I are having heated discussion on this.

[ellis_vener_photography]

Profiles are device specific. your monitor is a device. Their printer is a device. By crating a

device specific profile you are looking atthe character of that deviceand generating a set

of corrections to bring that device back to or closer to, neutrality. You should not be

converting your image to that profile but instead leave in in a device independent

"workspace' like sRGB or Adobe RGB (1998) and you use the Costco profile to softproof the

image to see where it needs to be tweaked if at all so that it will print as accurately as

possible to the original. Once again: Do NOT convert your iamge to a device specific

profile!

[vietnam photo]

You wrote "softproof the image to see where it needs to be tweaked if at all so that it will print as accurately as possible to the original". I think you said that the photographer should tweak the image so that it matches the soft proof and send in the tweaked image. If so, that seems a lot of work if the photograph has to repeat this step every time. The following instruction (step 14) from DryCreek Photo makes sense as the conversion is done automatically. http://drycreekphoto.com/Frontier/using_printer_profiles.htm

[emre]

You see, color space conversion involves trade-offs. When the destination gamut is smaller than the source gamut, do you want to trade-off overall saturation for clipping saturated colors, or the other way round? Since this is an aesthetic trade-off, it is best done by a human. This is why you have to do it for every image.

 

I do not understand why Ellis told you not to convert the file. Minilab printers to not like embedded profiles. In most cases, you SHOULD convert the image using their printer's profile and save to a new file.

[aardvarko]

You pre-convert the file to the Costco profile because the Costco Frontier systems don't have the capability of converting profiles; they are extremely primitive in terms of color management, and ignore embedded profiles altogether.

 

When submitting so-converted files, the operator must completely disable the Frontier's color "correction":

 

"# Fuji Frontier: No Corrections. A few labs use the PIC Pro module which allows printing in the "Import No Convert" mode. This gives a greater color range in saturated cyan tones. If the lab does not know what this is, or tells you that the mode is disabled, don't worry.

 

"* The FDIA/Image Intelligence auto-corrections and image enhancements must be disabled in the PIC module."

- drycreekphoto

[aardvarko]

Ellis, sorry, mate, but you're wrong on this one...

[marshall]

I hate to disagree with Ellis, but I'm with Chris here. I think what Ellis means is not to use the device-specific profile as your working space (a question which gets asked repeatedly on this forum).

 

After making all your edits to create and save a master file, you'd flatten the image and convert to the profile for the target printer. You may apply some additional sharpening at this stage. Then you'd save the file under a different name and take that file to be printed on the device you've converted it for.

 

Hope you and your brothers can work it out...

 

- MG

[klix]

Just to echo what others have said... the workflow is camera to (scanner, if needed to) monitor to printer.

 

You calibrate the first part (camera to monitor), then SOMEBODY has to calibrate that first part to the printer.

 

If you follow the drycreek.com instructions and use the provided ICC profiles, you would then instruct Costco NOT to apply any corrections.

 

If you fail to tell them NOT to correct/adjust, Costco will apply such adjustments, based on some unknown default.

 

So if you went through the time, effort and expense to calibrate your camera to your monitor, and adjust in PS, then wouldn't you want to make sure you control the last end of that flow?

 

KL

[ellis_vener_photography]

thanks (yes really) for letting me know when I'm wrong!

[biju_s]

> Do NOT convert your iamge to a device specific profile!<br>

With soft proofing one can select "intent" that looks best. How will they ensure that the printshop is using the same method, rendering engine and algorithm to make the print everytime?

 

I convert to costco profile and ask them to do no correction.

[emre]

<blockquote>With soft proofing one can select "intent" that looks best. How will they ensure that the printshop is using the same method, rendering engine and algorithm to make the print everytime? I convert to costco profile and ask them to do no correction.</blockquote>

That's because you do it for them, at the "Convert to Profile" stage. Once it is in their printer's color space, the only thing they have to do is to print with no adjustments.

[beauh44]

I'm certainly no printing guru, and I rarely send my prints off to a lab, but there's one aspect of this discussion though that leaves me a bit confused. In short, I would've thought Ellis' initial answer, that is, to not convert to the Costco profile, at the least, good advice.

 

Now there's probably something going on here that I don't understand, which isn't unusual, but first, let me cite a quote from Tim Grey's "Color Confidence" book regarding converting to profile:

 

"Some photographers also convert the image to the output profile as the final step before printing. Personally, I prefer not to use this method. However, if you are using a custom profile, you most certainly can. It won't make any difference in the final output if you use the correct settings, so it is really a matter of preference."

 

Tim's description is more in line with what I was thinking because surely, Costco - even if they don't convert to profile either - will have the destination space set to the correct profile and whatever profile is embedded with the image will be converted anyway, on the fly.

 

I used to convert my images to the paper/ink profile I was using and would sometimes screw up and save the converted image. When I would open it later, it would have a paper profile in it instead of my working space. In other words, assuming your output space or rendering intent is correct, isn't converting to profile redundant? (Now soft-proofing is a whole different ball of wax)

 

OK, let me have it! Tell me where I've gone wrong and why! BTW, my prints turn out great! ;-)

[marshall]

The issue is whether or not the lab actually makes use of the correct color space and profiles in the printing process. Generally, providing them a file in, say, aRGB, doesn't work because they don't really set a target space in the PS sense. Thus, getting them to print with all color corrections off and the file already prepped with the space is likely the safest way to go. But I don't do this a lot, so perhaps someone else can explain in more detail. Enjoy.

[beauh44]

Thanks Marshal. I guess I just wouldn't use Costco, personally.

[marshall]

Actually, though I don't use them myself, I know a few people who do so quite happily. The trick is not to count on them for expertise. If you prep the file right and get them to turn off any automated corrections, all they are is a pretty good output device that will print on real photographic paper up to 10x15 for a reasonable price. Useful, perhaps.

[vietnam photo]

Thanks everyone for a very insightful mail thread. I think Costco/Drycreek Photo makes sense because the photographer is in control throughout the entire workflow. The Costco or any lab printer is merely an output device and does not interpret/modify the image in any sense.

[aardvarko]

<i>Tim's description is more in line with what I was thinking because surely, Costco - even if they don't convert to profile either - will have the destination space set to the correct profile and whatever profile is embedded with the image will be converted anyway, on the fly.</i><br><br>See, the problem is that Costco's Frontier systems don't know HOW to convert between profiles. You have to do the work for them.

[ethan hansen]

<p>There is one reason not to convert an image to a printer profile before printing: If the final print destination and printer technology is unknown, or the same image will be printed on multiple printer types, converting to a printer profile can be dangerous. The reason is the conversion process discards all colors that do not fit within the printer gamut. The problem with this approach is you are completely at the mercy of the lab, service bureau, or print shop. If they assign some crazy profile to your image or do the standard Image>Mode>CMYK trick, the results are not going to be good. Some labs ask for images in sRGB because the prints will be made on one of a long line of printers. sRGB is the lowest common denominator color space, so the results will not be too horrible. These same labs often offer "color correction" services at an additional charge. This is usually nothing more than an automated conversion to the profile for the printer your job runs on.</p>

 

<p>There are drawbacks to the above approach. The first is you lose control over how the image will appear. A starting point is the rendering intent used - these govern how the color in your source image is crammed into the range of colors the printer can reproduce. You can see the effect for yourself. Open an image in Photoshop. Soft proof to a printer profile - any profile. Toggle between Relative Colorimetric and Perceptual intents. If you are using one of our (Dry Creek's) recent (since August '04) profiles, also check the Saturation intent. We used our own algorithm here to hold maximum saturation while maintaining overall image balance. Chances are, one of these options looks better than the rest. Different images benefit from different rendering intents. After reviewing a handful, you can quickly determine which will be best for each image. A lab that uses only one rendering option, usually unknown, takes away this control.</p>

 

<p>Another merit to performing your own profile conversions in Photoshop is the ability to use Black Point Compensation (BPC). The ICC specs do not state how differences in black points should be handled. Digital images tend to have darker blacks than any printer can reproduce. Many RIPs and color servers used by labs simply clip any tones darker than the printer's black to black. So much for your shadows. BPC intelligently scales the black levels to hold shadow detail that otherwise would be lost.</p>

 

<p>Finally, most labs with digital printers are not set to read input profiles. Some simply assume your files are in sRGB. Most digital printer drivers, however, just throw the raw color data at the printer. Fuji Frontier, Noritsu, Agfa, and similar machines are designed to do an OK job with sRGB input. If OK is good enough, by all means use sRGB. It is the closest standard color space to what these machines print in. That argument strikes me as the equivalent of advocating using Kodak Max and Fuji Superia rather than good films because mini labs are accustomed to it. The power of a digital printer is that you can bypass much of the operator ignorance and incompetance if they will merely print without all the 4x6 happy-snap auto corrections enabled. An accurate printer profile allows you to get the color and tonality you want rather than what some automated algorithm or lab operator thinks you should have.</p>

 

<p>The image below compares the midtone color range of two Fuji Frontier 370 printers on the same Crystal Archive paper. As you can see, the printers are neither a particularly good match to sRGB nor are they identical. That is why using sRGB is not your best choice nor is a generic Frontier profile going to work that well. Obviously a 2-D slice through a 3-D color space does not tell the entire story. You can build, view, and compare interactive gamut plots of various color spaces, printers, digital cameras, and scanners using <a href="http://www.drycreekphoto.com/tools/printer_gamuts/">VRML models on our web site</a>.

 

<p><img src="http://www.drycreekphoto.com/images/Gamuts/FrontierComparison.jpg"></p>

<p>If you have a VRML plug-in for your browser, you can also compare the color range for the above printers in <a href="http://www.drycreekphoto.com/tools/printer_gamuts/vrml/fuji/fuji-370-compare.htm">full 3-D glory</a>.</p>