7d with steadicam
 

if you use a 7d with a steadicam.
What kind of f-stop do you have to use ?
I can imagine if you just use F1.4 for example, it should be difficult to keep the subject in focus all the time what would result in a bad shot.
My guess is to have the f-stop at around f5.6 ?

If you can, shoot with a really wide lens like a 24mm or wider then set it to infinity. So if your subject is like 12 feet away and they are in focus at infinity, just don't get closer than 12ft. If you do need to be closer to a subject you may want to close down the aperture and/or getting a remote follow focus with an AC. This method works really well for me on my 5D. On the 7D you will probably want something more like a 16mm or the tokina 11-17mm.

Hey Cody,
Thanks for the info.
I have the 24-70mm f2.8 L Usm from Canon so I don't know if it will do.
Are the results from the Tokina any good ?
A remote Follow Focus ? Isn't really difficult or can the focus puller watch on an own external screen ?

Gents:

Without remote focus, you will need to start working "splits", where you set an intermediate setting that will give you the most range. Get yourselves a depth of field calculator--there are a number of apps available for the iPhone (I used pCam, which has a lot more to it and costs a lot more to boot).

In the example Cody listed above, you would not want to set it to infinity if you want the maximum range for your subject. Let's say you were shooting at f4. Setting the focus at infinity would give you from infinity to around 25' (not what we are looking for). Using the hyperfocal, which is the minimum distance that will hold subjects at infinity in focus (24'11"), you can hold from infinity down to 12'6". Not bad, but we can do better. If you set the distance at 12', you can now hold 23'1" to 8'1", which gives your subject a lot more room to move around--and you might start to throw your background a little out of focus, which of course is what everyone wants with these cameras. Get a little bit greedier, set your focus at 9', and you'll get 14' to 6'7", which gives you even more room for your subject to come close, and a softer background still.

Of course, stopping down will increase your range--switch to f8 and set the lens to 6'6", you'll now get 13'5" to 4'3", which is an obvious improvement. Bear in mind that these are numerical calculations and a given lens may have slightly different performance, but generally the calculators err on the forgiving side, so you are more inclined to see useable focus just outside the stated parameters.

Remote follow focus IS really difficult and it will be interesting to see how the indie world manages it as low-cost systems begin to arrive this year. Traditional AC's use a combination of techniques to judge camera to subject distance; monitors have become somewhat popular but not with all AC's. Generally when one pulls focus from a monitor, you are reacting after the fact and the pulls tends to be a little late. With a small stabilizer, running a lightweight BNC off the rig to a monitor is an additional operating challenge (HDMI cable, far worse). It is indeed possible for a good AC to maintain focus on handheld or Steadicam shots at an f1.4, depending on the lens--the longer they go, the better the AC needs to be. Somewhere around 50 to 75mm it starts to become unmanageable.

I'd curious what steady-cam rigs people are finding best for use on the the 7D. Any thoughts?

I have the Merlin with the arm and vest (total cost under $2500 as I recall) and it works great for the XH A1. Since the 7D even with a heavy lens is significantly lighter, it should be fine for it too. I haven't tried it yet but probably will before the next shoot.

Weight-wise the Merlin isn't a bad match, but you do have the limitations of the small screen for viewing, limiting how far you can rotate the camera from your body. The next model up, the Pilot, has an external screen and comes with the same vest and arm as the Merlin. If you are absolutely sure that you won't be adding any additional hardware to the camera and lens combination, you are OK with the Merlin, but if you were ever to add remote focus capabilities you will need the extra payload and power distribution of a rig like the Pilot. It may seem strange to spend more money on support gear than the camera itself, but bear in mind that people generally own tripods and stabilizers through multiple generations of cameras so it makes good sense to invest wisely in those.

Good point about the monitor. I've always used the Merlin setup with the XH A1's flipout LCD. But it's easier to see than the screen on the 7D, since it can be angled. The 7D screen might limit the range of vertical movement somewhat.

Spending more on accessories than the camera cost is something people need to be aware of--we should think of the camera as the engine...but without everything else, you can't drive it anyplace. Red likes to call theirs the "brain."

Oops, double post.

As always Charles gives advice that is soooo good he should charge for it!!! BTW I use a CMR Blackbird with my 7D and I really like it. I have tried the Merlin and the Glidecam alternatives and I really think it's a better setup than either. The Glidecams can really bind up your wrist pretty quickly. Here's a page that I have bookmarked on my Droid Phone that is pretty helpful for figuring out DOF pretty quickly. I am almost always shooting at 17mm so I can get away with a pretty good amount of movement.

Online Depth of Field Calculator

Hey Charles, thanks for clarifying all that! We can all learn a thing or two from this veteran!

Bart,

If you end up going to WPPI I'll meet up with you and let you try my rig (Steadicam Pilot w/ Canon 10-22mm) Works great for me!

Sage advice.

We've finally trimmed out our Merlin to where we can pull some fantastic shots, but the camera with the 17-55 lens is clearly near being maxed out on weight.

Only advice I could even attempt to offer is to keep your z-depth the same at all times....not easy or possible in all situations when you're using a Steadicam.

i´m wondering if i use a steadicam with a 7d or 5d, the weight of my lenses may interfy in the mobility of the steadicam?
i haven´t use the grip but guess all the big weight will be head on not on the back of the camara or down it, as it is in dv camcorders. Also depends on the sizes of the lenses, of course. So the stabilizer system that looks like a wheel may not be the most recommended for a 200mm lent, any ideas?