I had a rather bad surprise couple of days ago when starting using my iMac Alu 20" received last Wednesday. Yesterday morning, while displaying a RAW photo with Lightroom, I was surprised by artifacts, similar to those seen on compressed JPEG with blue sky. Then I forgot about it. Till yesterday evening when I displayed a gray to white scale with Omnigraffle... big shock! I obtained large stripes, with ugly sides...a disaster...Of course, if you purchase today the new iMac 20" for 1199€ (all taxes included), it will be a perfect companion for most users. However, if you plan to use it as a photo editing/reviewing platform, or more generally if you need support for 24-bits color and a wider view angle, then go for the new 24" iMac Alu, or the previous 20"/24" iMacs.
So I decided to display a white to black scale, and photos below illustrate the astonishing result. On the white side, the first 5 centimeters on the left are entirely white:
And on the right, the last 5 centimeters are fully black:
And in between one can see those vertical stripes of 1cm with ugly sides.
I started looking on the web, and with our friend Kiryu, we found the reference of the LCD panel being used in the new iMac 20" Alu from Kodawarisan. It is a TN panel, encoding colors in 18-bits (6-bits per RGB layer), instead of 24-bits for the previous 20" iMac, or the new 24" iMac Alu (IPS or MVA panel).
Of course, I can not make any use of this new iMac 20" Alu for my photo business, so I will try to negotiate with Apple to get It exchanged with either the previous iMac 20" or the new iMac 24" Alu. I screwed myself as I could not imagine Apple could have changed so dramatically the quality of the LCD panel used in iMacs.
One can indeed regret that Apple is not providing enough details regarding components being used in hardware models (LCD panel, true CPU/GPU specifications, etc.)
