Slight green tint on a B&W print

<p>Hey gang,</p>

<p>I did do a brief search this type of problem and nothing close to what i was looking for popped up, perhaps i didn't use the right keywords. So my apologies if this is a duplicate post.</p>

<p>I use Adobe Lightroom and Photoshop for all my post production. In this case i took a light blue monotoned picture that i had flattened in the past and created a virtual image and opened it up with photoshop. I just put a B&W adjustment layer on it as the client advised they wanted a pure B&W versus the monotoned print. After putting the B&W adjustment layer on the image. All looked well and i saved the image back into Lightroom. The historgram in Lightroom only shows "Gray" data (there are no RGB colors in the histogram). Given this i assumed all color information had been removed from the picture and i exported it as a sRGB JPG and sent it off for printing at a reputable website for large custom sized prints. </p>

<p>I just had the photo delivered and i am inspecting it and although very light, I immediately noticed a green hue to the picture as did my girlfriend. While both her and I think it looks kind of cool, this is not what the client requested, so I am trying to understand if i did something wrong in my post production workflow or not? Should i have converted the image to grayscale in Photoshop before saving it back to Lightroom? Does my monitor need to be calibrated? I would think that working in black and white, that color-wise monitor calibration would be as important as calibration for brightness, etc.</p>

<p>Please help. I want to get this right and make the client happy.</p>

<p>PS - This is my first sale.</p>

<p>Thanks in Advance...</p>

<p>-B</p>

<p>Others will likely have more to say on this, but I'll start off by saying that printing digital B&W is a whole science and art on its own. There are no easy answers, but note that even though your file may have only had gray information, you're working in an RGB system (JPEG represents in the data in RGB, and the printer will involve an RGB/CMYK process). From my limited experience, using such a system will almost always have a colour cast of some sort. If this is not tolerable, you need to use a specialized process, which likely involves black-only inks, or some other specialized ink system.</p>

<p>Thanks for the reply Karl!</p>

<p>I could understand a slight twinge of color in a B&W print. But we unrolled this print on the kitchen table with nothing to compare against and said what's this green tint immediately. Here is the breakdown on the specifications.</p>

<p>Printer and inks used: HP Z6100, with Vivera Archival Inks<br>

Paper: HP Premium Photographic Satin Paper<br>

B&W prints desc: Uses black and gray inks to create black/white prints. Always perfect<br>

Misc desc: Archival. Excellent color. Perfect b/w's. Minimal graininess</p>

<p>Based off your comments and the description provided from the website...should have been pure B&W unless there was still some color in the image file which there shouldn't be...I am at a complete loss here.</p>

<p>Any further comments are definitely welcome!</p>

<p>Likely the printing service you used did not adjust their printer correctly. I used to manage a 1Hour Lab, and we used the Fuji Frontier printer, same as many "pro" labs use for their smaller prints. Anytime we tried to print a B&W picture through on normal settings there would be a green tint to it. There is an adjustment for monochrome pictures (simply labeled "monochrome adjustment") that we had to select before printing. This involved all of about two clicks with the mouse, very simple but commonly overlooked.</p>

<p>I'd be willing to bet that the printing service you used simply ran the pics through without making this adjustment.</p>

Thanks Luc. I have an email out to the customer service dept. I am bit peeved because this was a 48x19 print. I will let

you know what they come back with, thanks for info...it is truly appreciated!

<p>It's an sRGB JPEG that contains 3 color channels. I would expect that the printer driver or rip saw it as a color image and used all the ink colors.</p>

<p>Yea, looks like a mistake on their end. The "green tint problem" is actually very common, but it usually happens in the 1-Hour Labs where the employees are not properly trained. When I was manager I made sure all of my employees were aware of it, but even then they would still forget from time to time, usually when we were real busy.</p>

<p>But for a "pro" lab to make that mistake, and on such a big print, should not happen. They need to fix that for you no doubt. Good luck, hope it gets fixed quick!</p>

<p>Have you tried viewing it under a tungsten only light source? If so, is the cast still there?</p>

<p>There is a common problem with prints printed with inkjets that they have a green colour cast under daylight which shifts to magenta under tungsten. It's due to the way the inks flouresce. The phenomenon is called 'metamerism', and is quite different from the cool/warm colour change you normally get between daylight/tungsten. More recent inks have reduced the effect, but it still exists.</p>

<p>It is a 2 decade plus curse with inkjet. One can make a perfect print and with fading or screwed up calibration one will get a shift. When inkjet first came out this was a bigger issue than today.<br>

<br /> One had the issue that the public "wants" B&W inkjet to cost 1/3 of what color inkjet costs; but one uses the same amount of ink. PLUS folks are more sensitive to a hint of color in a B&W print than a slight shift in hue with color. Thus B&W pictorial's cost in inkjet is more than color inkjet and it is harder sometimes; and they want it at 1/3 the cost.<br>

This is an 1980's topic!</p>

<p>Sorry, but it's not just an "inkjet phenomenon." The Fuji Frontier printer I mentioned above is a Laser printer, not an inkjet. The green tint is still there if not adjusted before printing. Now this was almost 10 years ago, so I really don't remember the scientific details as to WHY this happens (something to do with the developing process), I just remember that it does happen on the laser printer unless the adjustment is made.</p>

<p>And this was all run by computer as well, like I said the adjustment involved two clicks of the mouse.</p>

Thanks for all the responses!

 

I heard back from customer service. The production manager reviewed my image and agreed it should have been pure

B&W. He said that he would personally reprint it and review it before sending it off free of charge!

 

I recieved a shipment notification so I presume all is well - I will let you know how it looks!

 

Thanks again!

 

-B