<H1>Canon EOS-1D X vs. EOS-1D MK IV camera comparison</H1>

Now that the long awaited, Canon EOS-1D X camera has arrived in camera stores across the world, many photo enthusiasts often ask me whether I will be selling my EOS-1D MK IV and upgrading to the new camera.  Let us refresh ourselves with their respective major specifications :

EOS-1D X body

• 18 MP sensor powered by dual Digic 5+ processors, 3.2 inch, 1040K dot LCD screen.
• Dual CF card slots with 12 fps and 14 fps (with mirror lockup).
• ISO range from 100 - 51200, up to 204800 with expansion.
• 61-point High Density Reticular AF with dedicated metering powered by a Digic 4 processor.
• The number of cross-points depends on the speed of the lens used.
• 36 ms. shutter lag, 400,000 cycle shutter and .76x viewfinder.  

EOS-1D MK IV body

• 16 MP sensor powered by dual Digic 4 processors, 3.0 inch, 920K dot LCD screen.
• One CF and one SD card slot with 10 fps.
• ISO range from 100 - 12800, up to 102400 with expansion.
• 45-point AF system with 39 cross-points.
• 104 ms. shutter lag, 300,000 cycle shutter and .59x viewfinder.

I have been using the EOS-1D MK IV as my main body for about 3 years now and am very pleased with its performance and rugged reliability. In fact, my confidence rose to the level that I sold my EOS-1D MK III when the EOS 7D was introduced and used it as my backup camera. Now I am about to make another decision, should I keep the EOS1-D MK IV as my backup camera once I take delivery of the EOS-1D X.

It is not an easy decision. Thankfully, both 1D cameras share the same new battery and charger. Their specs are similar but the burst speed, additional AF points and better high ISO performance of the EOS-1D X should give me an extra edge on photographing wildlife, especially moving ones. With the 1D MK IV, anything shot with ISO 3200 or above has unacceptable noise level to me and I expect the 1D X will perform a little better but perhaps ISO 6400 may be its acceptable upper limit. One major difference is the 1D X cannot auto focus on apertures beyond f/5.6 while the 1D MK IV can go up to f/8.

My preference is to handhold my camera and travel light on photo shoots so I usually bring two camera bodies and 3 lenses with me. Therefore, on most photo shoots, my upper limit on prime lens I can bring with me is the Canon 400mm f/4 DO. With the 1.4X extender, the EOS-1D X offers me a focal length of 560mm with AF while the EOS-1D MK IV gives me a reach of over 1000mm with AF using the 2.0X extender.

Each camera offers key features I cannot get in the other but combined, they give me unparalleled level of performance.  In addition, Canon will be discontinuing the APS-H format so the EOS-1D MK IV will be the last camera with that sensor technology. I really like this sensor because it provides a professional camera's performance with an extra reach, unlike the EOS 7D. I will definitely keep the 1D MK IV as my main backup camera and use the 7D as the secondary backup body.

I have now received my EOS-1D X camera and have taken it to Alaska and Canada for a grueling wildlife photo shoot. Take a look at my review here and visit my website MichaelDanielHo.com to see many Travel and Wildlife photos taken with both cameras and you can follow my travels on Facebook.