Hi folks. I'm having a little trouble finding documentation on the amount of recording time I can get on a C100 depending on SD Card size. I'll be renting 3 for Union camera operators for a conference coming up and I just want to have an idea of how far a 128 GB card will go. Is there a link, or an algorithm or some place where I can find out?

Hi Josh,

Referring to http://cinemaeos.usa.canon.com/wp-content/uploads/2014/04/EOS_C100_Brochure.pdf

On page 12 it says 355 min. on a 64GB card at 24mbps, full res (see attached image)

Looks like you could get 700 minutes, conservatively, on a 128GB card. That's nearly 12 hours.

Hope this helps!

ah! There it is. I was looking for it and couldn't find it. That's a crazy difference. With my GH4 at 1920X1080 24P @100 MBPS (and it goes up 200 MBs) it's 1 hour and 51 minutes. I generally don't like to record lower than 100 MBPS (though 50 is an option also).

C100 max is at 24Mbps it looks like. So one 128 GB on C100 would last the entire conference day. Wow. I wonder if there's a super noticeable difference in quality between the C100 and my GH4 then for something as simple as a speaker on stage at a live conference.

Yes, there's a difference: the C100 looks better (in my opinion).

You also can record on two cards at once, so in the unlikely occurrence of one card failing, you have a backup.

Yeah I really dig the double record. For a live conference with 7 camera operators coming up the offload times for footage are challenging. Knowing I can just give 2 card to each operator so that if one fails the other doesn't is a huge piece of mind and timesaver.

I'm curious. If the C100's recording bit rate at 24mbps is less than 1/4th of the GH4's 100Mbps (actually the GH4 can have 8 times the bit rate with 200Mbps, but the cards fill up too quick) why would C100 look better? The larger sensor?

C100 has a better, much larger sensor and DSP. I had a GH4 and sold it to buy the C100. No comparison. The GH4 is noisy, difficult to achieve shallow DOF and overall, I never liked the images. Others do but I suspect most people who like the the GH4 have never shot with a professional video camera. Coming from a mobile phone or low end camcorder, the GH4 is nice. Coming from shooting FS7/C100/300, the GH4 is pretty bad although I have seen a few DPs make it sing, but only with HEAVY post processing and massaging, shooting V-log.

I own the Atomos Ninja Blade and I must say, Canon's implementation of AVCHD is the best I have ever seen. When I side by side compare Prores HQ (220Mbps) versus the AVCHD out of the C100, there is very, very little discernible difference. With AVCHD, if you "break" the codec, by say, shooting millions of leaves fluttering in the wind on hundreds of trees, you can break the codec. If you do a ton of whip pans, you can break the codec. If you are shooting green screen, the 4:2:2 10 bit recording from the Blade with be superior to AVCHD. Other than those kinds of situations, the AVCHD built in on the C100 is outstanding, I am really impressed and before owning this camera, I hated AVCHD, it was subpar.

The AVCHD codec has been popular enough though for a long time that the Canon engineers were able to fine tune it to look really quite amazing. The Ninja Blade is a great addition to the C100 and I mostly shoot Prores HQ but twice, I have had SSD issues with the Blade and the dual recording backup AVCHD from camera saved my rear. Yes, I record three streams, Blade and dual record on the camera. You can never have too much back up.