Berkshires (Becket Massachusetts); © reserved 2009, Richard Lovison

It was a cold, damp, foggy morning… great for saturated colors.

I’ve been watching the development of CombineZP for a while now, playing with it from time to time to check out the results. The program has come a long way since its beginning.

CZP is designed to work under the Windows operating system and its function is to process stacks of digital images having the same width and height. The particular type of stacked images this article makes reference to is a focus stack in which each individual image of the stack is focused at a point deeper into the scene. A merge of all these images produces a final result with a huge depth of field.

This function of CZP is similar to the function of another popular program, Helicon Focus, though because CZP is freely available and licensed under the GNU public license, it doesn’t have the expense of Helicon Focus. However, this freedom doesn’t come without a price as the program does have a steep learning curve. One can join a Yahoo group associated with CZP and there find a helpful group of folks including the author of the program, Alan Hadley.

The next seven images were taken with an Olympus E-3 and a Vivitar Series 1 Macro Zoom mounted on a tripod. In each image, the focus was a little further toward the back of the flower. As I understand it, currently, the program is only designed to work with 8 bit images though all seven images of the stack were 16 bit tiffs. There wasn’t any problem with the import though I was only able to save the final merge as an 8 bit tiff.

Image 1 - © reserved 2009, Richard Lovison

Image 2 - © reserved 2009, Richard Lovison

Image 3 - © reserved 2009, Richard Lovison

Image 4 - © reserved 2009, Richard Lovison

Image 5 - © reserved 2009, Richard Lovison

Image 6 - © reserved 2009, Richard Lovison

Image 7 - © reserved 2009, Richard Lovison

The image below was the final result of a merge using the two functions; “Align and Balance Used Frames (Quick)” and “Do Stack.”

Final Merge - © reserved 2009, Richard Lovison

I did some quick editing in CS2 to remove the leaves in the lower right hand corner but that was all. This particular merge didn’t produce any artifacts to remove (something to be expected) and another test on a different series of images produced only a few artifacts that were easily taken care of in CS2.

CombineZP is definitely worth checking out if your passion is macro photography. And if you are so inclined, you can also contribute to the development process.

I hope I’m not confusing my readers due to the three articles that preceded this one that focused on the calibration of the Dell 2209WA. Quality information on monitor calibration, print viewing conditions and color management isn’t all that easy to find on the web and very few good books are written on the subject. What little I’ve found is often dated and usually brings up more questions than answers. In any case, I take the knowledge I gather and experiment on my own. Hopefully my documented journey of discovery with its mistakes and triumphs will help others in their explorations.

Up until now, I have used an Ott-Lite TrueColor task lamp for viewing prints made on an Epson R1900 using icc printer profiles from Epson and Red River for the different paper surfaces that I use. There was a good match between the print viewed under this light source and the image viewed on the Dell 2209WA calibrated at 6500K though there were many times when the print just didn’t seem right or looked slightly more cyan than the monitor. From what I know now this was probably due to the color temperature of the Ott-Lite being around 5500K and the fact that it was a fluorescent light source, a source noted for having spikes in its spectrum.

I recently came across an article on the web offering advice on setting up a working space for digital color imaging and discovered that a D50 (5000K) light source was recommended for proofing. The D50 standard was chosen as it appears color neutral to the human eye and is close to the color temperature of most homes and offices that are illuminated with a combination of sunlight and tungsten or fluorescent. A SoLux lamp with a halogen 4700K bulb meets this requirement. So I did a search and bought a SoLux task lamp from a seller on eBay at a great price of $55 — the seller no longer stocks them and they are getting more difficult to find on eBay. Tailored Lighting sells two different clamp-on fixtures that are reasonably priced. If you purchase one, don’t bother with the diffuser.

SoLux Task Lamp Model 19103

It’s extremely well made and came with a 50 watt, 36 degree, 4700K SoLux halogen bulb.

SoLux MR-16 Halogen

The SoLux bulbs are highly recommended by many professional photographers as the light of choice for viewing prints in a digital imaging environment. This is due to the spectrum of the lamp being a close match to daylight as shown in the image below.

Spectral Power Distribution Curves

You may find a less expensive alternative by finding a lamp at a local lamp or office supply store that will take a MR-16 type bulb as the SoLux halogen bulbs can be purchased separately.

When I first viewed a print under the SoLux lamp it appeared warmer than the monitor image. A tech at Tailored Lighting suggested I remove the diffused glass element in front of the halogen bulb that came with the lamp. This brought the match closer though the print still appeared slightly warmer. Then I read that some photographers felt the monitor needed to be slightly warmer than the standard of 6500K to get a good print match with a D50 viewing lamp… somewhere closer to 6000K.

From previous experiments I discovered that the native color temperature of the 2209WA with its default settings (RGB settings at 100%) is warmer than 6500K. So I set the Spyder2Pro initial calibration settings to native 2.2 and chose a measured luminance and aimed for a 140cd/m² white point. To achieve this I ended up having my contrast at 73% (this was needed to flatten the gamma curve produced in Colorimetre HCFR) and my brightness at 17%.

Note: Please don’t assume you can use my calibration settings or even my profile if I provided it and hope to achieve the same results. My settings are only provided here as a reference. You need to calibrate your own system with a colorimeter and produce your own profile based on your particular 2209WA and your video card.

After checking my results in Colorimetre HCFR, my color temperature was shown to be slightly higher than 6000K. The gamma and luminance curves looked fine. The match between the image on the monitor and the print viewed under the SoLux bulb was outstanding. The SoLux bulb was a big improvement over the Ott-Lite.

At this point you might be wondering why a match occurs between a print viewed under a D50 light source and an image on a monitor calibrated at 6000K when the color temperatures of the two sources differ. As I understand it, the brain “sees” an image on a monitor (emitted light) differently than it “sees” a print viewed with reflected light. A slightly bluer or colder light from the monitor makes up for this difference and thus one can then get a good color match. And I’ll bet the color temperature difference needed is probably not the same for everyone. Others may require a warmer color temperature for the monitor than I have to get a match while others may require a cooler temperature. There doesn’t seem to be a solution that works for everyone. And this is probably because not everyone perceives color in exactly the same way.

I currently don’t have ideal conditions in my “digital darkroom”… the walls and counter space are not neutral grays and the ambient light is not consistent during the day though the SoLux bulb provides the only ambient light at night. This setup works for me at the moment though I know it can be improved upon. One person wrote that the degree of color match between print and monitor is directly related to how much money you are willing to spend. So far that bit of info in my search for knowledge on color management holds the most truth.

Lily; © reserved 2009, Richard Lovison

One more capture before the frost hits tonight.