I work with multiple cameras depending on the application. For the best picture quality, especially in low light, I am currently using the D700. For longer reach, using telephotos, I use the D7000. Most recently, for reduced size & weight, I am using the Nikon V1 system. It was using this latest system that prompted me to look at how I could set up the cameras, and post-production workflow, to both optimize picture quality as well as ensure consistent image "look" across cameras. Achieving a consistent look is challenging since each camera has different resolution, quality and size of sensor, different lenses and different response to light and color, albeit subtle.
I came into this guessing that if the presentation output were "constrained" - in my case the target was 8" X 10" prints, then these cameras could be used interchangeably, under a broad variety of circumstances, without discernable differences in the quality of the output. What was needed was a way to calibrate each camera to a common standard, to find an optimal set of image editing presets (sharpening, camera calibration, noise reduction, etc.) that gave best-case picture quality, and then to measure and understand the limitations of each camera to find out under what circumstances they "diverged".
The first tool I explored was the ColorChecker Passport. This is a standard set of color targets used to make a custom camera calibration profile that can be used in Lightroom. By creating profiles for each camera, under similar lighting conditions, theoretically, the color rendition of each camera will be the same. Refer to the X-Rite website (www.xritephoto.com) for more information.
Using the Passport, I calibrated my D700, D7000 and V1 and took the same shot:
While these images are too small to see the detail, the overall similarity of color, and quality, are comparable.
Interestingly, I ended up using more or less the same capture sharpening on all pictures:
53/0.7/74. This seemed to give the optimum sharpness for low-ISO, high detail pictures.
I then took some comparison shots, indoors, at higher ISO. I shot all the way up to ISO6400 but really analyzed up to 3200. In 8X10 prints (equiv), the V1 held up very well up to ISO 3200 with no noise reduction and standard sharpening (53/0.7/74). I ended up dialing in a small amount of NR at 3200 (15/50/10). the resulting V1 image was virtually identical to the D700 image @3200. Remarkable!
Note: depending on the image, it may take NR in the range 15 - 25 to achieve best results.
What I learned:
1. In order to achieve similar images between all cameras, it is necessary to calibrate each using the ColorChecker Passport. It is recommended that you create a number of profiles that can be re-used: Outdoors-sunny, overcast. Indoors-flourescent, mixed (flourescent + daylight through a window). Flash, etc. This calibration process eliminates any color differences and can also be used to set white balance.
2. For high ISO's (>=1600), due to higher noise, the images begin to lose contrast and saturation. In fact, this effect can be more objectionable than the noise itself which is less visible in print. I tried to minimize this by calibrating the camera at the set ISO. In measuring the color squares it looks like this doesn't make much difference. Hence a calibration works for all ISO's. However, because the Passport target will look noisy, smooth the colors out using NR before using the ink-dropper for white balance. Otherwise it will be difficult to click on the correct grey.
3. The V1 imaging is perfectly acceptable (compared to the D700) with 8" X 10" prints at 300dpi. This assumes no significant cropping beyond clipping to 8X10. The useability range is at least ISO 200 - 3200 and perhaps beyond. I'd also like to try printing at lower dpi just to see if there is any difference (240dpi versus 300dpi would allow for a 30% crop). Note: the "native" resolution of the Epson 3880 is 360dpi. I need to ry some experiments to see if up-resing to this resolution makes any difference.
4. While the images are very similar, the D700 is, naturally, slightly sharper and has slightly brighter colors. It's subtle. If you want the absolute best quality, or to print to larger paper than 8.5 X 11, the D700 is still the camera of choice. However, if the circumstance requires a smaller camera, I'd defy the casual observer to tell the difference between D700 and V1 prints, web galleries or AppleTV output. This is a nice outcome.
5. As an aside, I see no reason to use NR on D700 images, up to ISO3200. I have not tested beyond that. I'd guess that NR is only needed on the V1 at ISO 1600 and 3200. My suggesteions for NR would be:
V1, ISO1600 - 10/50/10
V1, ISO3200 - 15-25/50/10
V1, ISO6400 - 30/50/10
All sharpen settings to 53/0.7/74
Note 1: While prints at ISO3200 look fine, at 6400 you can start to see noise artifacts plus (despite camera calibration) subtle color shifts and loss of contrast/saturation. While perfectly acceptable for web/AppleTV, and OK in 8X10 prints (so long as you don't do a back-to-back comaprison with the D700@ISO200), I'm not excited about using this ISO setting for the V1 unless it's an emergency.
Note 2: Ultimately, I'd like to get to a point where I'm not needing to calibrate the camera every time I'm using it. Hence the idea to create "standard" profiles that can be re-used. I will experiment with this as I use the cameras more. It will stiil be necessary, however, to calibrate white balance using a gray card on every shoot.