C100: C100 changes f-stop without cause! Damn inconvenient

nedcam

nedcam

Well-known member
I am locked in a closed set for 5 days shooting for a federal government agency, doing a lot of lab training videos to keep you all from getting poisoned and the agency out of the headlines. So continuity is a Total Nightmare and my client asks several times every 15 minutes, sometimes every two minutes, for me to go from camera mode to media mode to check something out, like which scientist held what test tube in what hand and who was doing what in the background, etc. I go to media mode, play a few takes back, but when I go back to camera mode it is no where near the same f-stop!!!! The camera has decided to widely change my aperture without asking me!!! The damn C100 half the time forgets what the stop was and suddenly I'm over or under, big time. The problem is, if I take mental note of what the stop is before I got to media mode, say 6.3 or 7.1, when I return to camera mode there are 2 or 3 detents on the control scroll wheel for many of the stops, so I have no way of knowing which is EXACTLY the fraction of a stop I was at. We're moving at such a fast speed I can't stop and take notes. I EXPECT A PROFESSIONAL LEVEL CAMERA NOT TO DO THIS! It is sabotaging me!

What makes it worse is the producer client will also be the editor so he will notice these slight changes. What makes it even worser, and was a major thread a few months ago, is the G*d D*mn 24-105 loses transmission when I have to snap in for a close up (every 5 minutes) so I have to open up for that, but I digress...

So, anyone else have this problem, where when you toggle back and forth from camera to media mode it decides to change f-stop? This is a real hassle. 5 ten hour days of having to guess where I left off. My half ass solution is using zebras at 95% and trying to remember how many were in which hot spot. Ugh... I used to love this thing...
 
Can't help you with your problem Ned, sorry but if you had a Ninja Blade, it is child's play to instantly play back clips, scroll, rewind, etc. without disturbing the camera at all. I only know this because I had a shoot last month with a client who was the same, needed to review a lot of takes, all of the time and I was thinking how cool it was that I had the Blade with an SSD, it is all so quick and responsive. LOVE my Blade! I rarely shoot without it. I suppose you could switch out your EOS lens for a manual aperture Nikon or something if you have any non EOS lenses and adapters?
 
Ned, I use a Canon C100 with Canon Eos lenses and use both Camera and Media mode all the time and I have never had this problem. In fact I don't know how the f-stop could be changing . I have tried to duplicate what you are doing with no success. Can you give me an idea what the settings are on the camera, shutter, f-stop, iso.
 
As stated, Ninja Blade with help. Also if you can try renting some manual glass. (Rokinon) That way the camera can't change your stop. I use rokinon cine lenses are they are really nice and sharp. Especially at f/4.5-6
 
Also use the ninjablade for playback.
But you could pull the sd card from the camera and playback on a laptop , maybe that would be a workaround for this strange fenomenon.

edit:
I can't seem to replicate your fenomenon when switching between camera and media mode , the camera remembers the f-stop.
have you tried using a different lens? maybe it's a bad lens connection????
 
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Wow that does suck. I usually play back through the blade as well, as it's much faster.

Re: Transmission loss, I did a lot of tests and for sure, the 24-105 does not have any TL if you keep it wide open. As soon as you stop down it does. Weird quirk... you could try manual lenses.
 
De-attach the lens ever so slightly so there's no communication. When you want to change F-stop, twist it to lock, change, detach slightly.

Just the quick fix I could think off without sending the camera/lens off to Canon (which you should do after the job)
 
Is your stop adjustment set to "fine" or "1/3" (or "1/2")?

If you change it from fine you should at least be able to get it back to the right f stop quickly.
 
Thanks for the replies. I do have it set to Fine. Yes I love the Blade, came close to buying one but...not having an eye loupe is a deal breaker for me. I shoot a lot of handheld often in bright daylight and I need my eye plastered to an eyecup, that's why I love my DP4.

So I just returned from shoot day 3 and I'd say it does the problem about half the time, when I return to camera mode the stop is off around 2 stops, usually hotter. You guys are lucky it doesn't happen to you, perhaps because I'm on my 2nd mother board? It's a big PITA. The director is real sharp and came up with a critical solution to not having to spend time rewinding for continuity: When there is a critical moment he takes a silent cell phone pic of the monitor! This has cut down on the amount of times playback has been requested.

Guess I will take it into Canon service when I get slow, I'm on the loaner plan.

Thanks!

P.S. For the first time in my life I left ALL my gear on site for a five day shoot. That's how strong security in government labs is. Like a vault!
 
Interesting experience. Not sure why the camera would change f stop, unless it is in some kind of auto mode like auto iris.
 
No not in auto. In fact, when it does change the f-stop upon returning to camera mode it is either over or under exposed.
 
So, the f-stop changes (say from f4 to f5.6) just by going from Camera mode to media mode? If so, then there is something wrong with the camera/lens. Does it do it with different lenses? Then maybe the problem could be narrowed to the camera. Does it do this with a prime lens?
 
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