Cat6 Vs Coaxial Cable For Analog Camera

Using Cat6 allows for future upgrade to IP cameras.

Depends on the amount of expected potential line interference. Cat 6 is NOT your magic bullet for CCTV installs, even with baluns, because they are not shielded. Coaxial cable is shielded and can better deal with nearby power sources (which generally should be avoided, but not all installers are perfect).

If you want a catch-all solution, have a stupid amount of money, and can run pretty thick ass cable, you can go for Cat 7 (or the currently still mythical Cat 8). Phrased differently, you ideally want S/FTP, a minimum of FTP or STP, but NOT UTP.

Let's be real though, it's all about knowing the job placed in front of you. Throwing out blanket statements for what cable you tell your installers to use isn't honest guidance. Actually learn about use-case scenarios and how to adapt to real-world situations and pass that along to your dealers if you truly want to advance the level of support you provide your installer base.

I would recommend using the best cable for the specific job. In the case of analogue cameras from my experience Coax is significantly better than running twisted pair cables like cat6 with baluns. Like Robert Shih said, Coax can deal with external interference much better because of the shielding. Additionally the copper conductor inside Coax cable is generally much thicker than on Cat6 which allows for the transmission of the signals with less resistance which improves the image quality received by the recorder over longer distances.

If you want to do a great job as well as future proof the installation just pull through Coax and Cat6. Just make sure you dont go over the 100m mark.

Another thing to consider is that Cat6 is already overkill for cameras. With current day camera bandwidths you could even use CAT3 for most jobs. I can not imagine a day where you would need 1000Mbps (Cat6@100m) or 10,000Mbps (Cat6@55m) bandwidth for one camera. Its like building a road that can handle 10,000 cars per second when the current use is only 7 cars per second which will most likely reduce in the future as is the case with camera bandwidth requirements. H.264 --> H.264+ --> H.265 --> H.265+ --> H.26........

Which will outpace the other? Megapixels or encoding capabilities? 

There are some mistakes people make regarding UTP cables:

1) Despite they aren't shielded, they do a really good job dealing with interference because they are balanced

2) You can't use shielded twisted pair cables for CCTV

3) Using baluns with 50 ohms BNC connectors instead of 75 ohms

4) Most of baluns are not suitable for outdoor use

I explain why in this article I published in my website: UTP Cabling (http://www.cctvinstitute.com.br/cabling---part-4---utp.html )

It's part of a series of four articles about cabling.

And yes, I tottaly agree that using a coax cable is much better than using UTP cable with baluns for CCTV. 

In this article I talk about coax cables:  

http://www.cctvinstitute.com.br/cabling---parte-3---coax.html

And here I talk about the big mistake manufacturers are doing regarding BNC connectors: Believe it or not, most of the cameras, DVRs and baluns are using 50 ohms connectors! I talk about that in this article: http://www.cctvinstitute.com.br/bnc-75-or-50-ohms.html