I have a chance to test the AC90 video camera as my organization is looking at purchasing new cameras to replace the existing ones. My usual way of testing a camera is to put it to a real world shoot and see how it would fare and also if I am comfortable with the handling ergonomics.
Lens and Sensor
I think it is quite unfortunate for Panasonic to use the tiny 1/4.7 inch 3MOS sensors (3 x CMOS) although the back-lit sensor technology is supposed to compensate somehow. Bucking the industry trend of moving towards larger sensors, Panasonic no doubt did this to keep the cost of the camera affordable for the masses. However, the small chip really lowers the low light ability significantly.
I have the chance of testing Canon XF105 recently and I have included the comparison of low light footages between the two cameras at the end. You can see that AC90 is quite significantly dimmer when both cameras lens are at their widest aperture. Note that Canon XF105 uses a single chip 1/3 inch CMOS sensor.
I have also tested the camera with Dynamic Range Stretcher (DRS) set at maximum strength (+3). On hindsight, it would be good if I could test DRS at 0 (off) as DRS may cause the noise/grain to increase in the shadow areas in order to stretch the dynamic range further. Barry Green and other reviewers have pointed out that the image is quite clean even with gain on. I supposed that is with the DRS off but I would not know until I test the camera again.
As pointed by Barry Green in his reviews and chart tests, the camera is very sharp as long as the F-stop is kept at or below F6.4. Lens diffraction sets in and softens the image particularly at around F11. See the footage shot at F11 between 00:13 and 00:23, image resolution loss is quite obvious. Serious shooters will want to consider using an external Neutral Density filter and buy one that does not degrade your image.
One unexpected but nice feature is the 3 dedicated rings for focus, zoom and iris. This is usually found on higher end cameras and even my previously owned Panasonic HPX172 P2 camera has only 2 rings. However, all the rings are infinite (i.e. they keep turning endlessly) and the zoom ring mechanism has an obvious lag. I would rather use the zoom rocker as it provides instant feedback.
The camera is well designed and feels solidly built. It is slightly smaller and lighter than HMC150 and around the same size as DVX100. Although the camera is a little bit front heavy, it is not a big concern since my left hand would be holding the flip out LCD screen or the focus ring.
I have always preferred the LCD screen to be situated on the front top just like Sony cameras (such as EX1) since this enables the shooter to rest the back/battery on the shoulder to add an additional stabilization point. This also proves to be less tiring than holding the camera with only two hands. If you look at HMC150 or DVX100, the LCD screen is placed at the middle and you cannot rest the camera on the shoulder because the LCD screen would be too near to your eyes for comfort.
The buttons are nicely placed on the left side. The camera is easier to operate than past Panasonic cameras or many competitors. For example, if you want to do white balancing, one button serves it all. You can toggle the button between ATW, ATW Lock, 3200K, 5600K and Ach (A channel). To do white balancing, just hold the same button at Ach and the camera starts to calibrate. How simple is that? Resetting the Time Code also proves to be simpler than HMC150.
The focus assistance (peaking) works quite nicely and the histogram/zebra helps to nail the exposure adequately. The LCD touch screen also makes it easy to watch replays or to navigate around the menu. Fingerprint is a non-issue as you practically see no fingerprints once the LCD screen is turned on. The sharp and clear LCD screen also performs well under bright sunlight in the outdoors. I did not enable the “bright” backlight setting for the LCD screen when I am outdoors but it is a comfort to know it is there. The electronic viewfinder feels rather low resolution and outdated but it is not that relevant since the LCD screen is usable in bright outdoors.
The AC90 camera uses the CGA-D54s battery and it lasts and lasts during my test. Although not an infolithium model which tells you the capacity left by the minutes, there are 4 battery bars on the LCD screen when fully charged. During my test, the battery indicator did not even drop one bar. When I went back to my office, I purposely left the camera on and it finally dropped a bar after some time. Panasonic instruction manual has stated that the battery will last around 6 hours and this is pretty impressive. This could be the blessing in disguise for using the smaller CMOS sensor.
Well, a camera at such an attractive price point cannot possibly have everything right?
One of the limitations is that the camera can only record 1080 modes. There are no 720 modes but it is not a killing factor since you can always resize and edit 1080 footages at 720. On the other hand, we get 1080p50 in PAL land or 1080p60 in the NTSC markets. This enables us to get true slow motion when playing back 1080p50 in 25 fps.
Another limitation in general is that the camera comes with lesser features. You get histogram instead of wave-form monitor. No magnified focus assist. No infolithium battery. Only 12X zoom.
However, these are all very acceptable limitations considering the price point. The histogram serves the same purpose as a wave-form monitor and you should always zoom in all the way to focus properly. All professional shooters always have more than one battery on standby and the 12X zoom is sufficient for most uses. If not enough, the 25X digital iZoom seems quite usable (see 03:50) or you can always move the camera nearer.
The blessing in disguise of having lesser features is also that the menu is much simpler to navigate and the camera feels easier to operate and learn for people looking to upgrade to their first professional camera.
There is also the Pre-Rec feature that does pre-buffering recording and scene files which enable customization of the image settings. For all my camera tests, I always switch to Cinema Gamma as I am always trying to achieve the coveted film look. Optical image stabilizer also works wonderfully, giving a little bit of the Steadicam look.
One image concern I have is that the skin tone appears a little greenish when there is insufficient light (see 01:25). However, the skin tone looks okay when there is enough light to feed the camera (see 01:35). Given its poorer low light capability as mentioned earlier, this is one camera that really needs proper lighting. Then again, even a 1/3 inch sensor is of little use when lighting is poor. That’s when some will resort to a full frame DSLR.
Panasonic AG-AC90 is a very capable video camera for its amazing price (US$1999 on B&H as of this writing). I am actually willing to pay more for Panasonic to utilize 1/3 inch sensors to improve its low light capability. That would have made it a perfect camera for professional entry level.