How can I solve the problem of viewfinder lag when shooting video with a DSLR?

Question

I use my DSLR camera to shoot videos of moving subjects (such as a car), and sometimes I pan the camera to track the subjects as they move.

The problem I have is that to track the subject, I have to watch the video screen and coordinate my hand movements. But the video image has a non-trivial lag. Furthermore I usually use image stabilized lenses (and mode 2) which reduce shake and improve the watchability of the recorded video, but adds more lag and non-linearity to my panning movements.

So the proposed solution I came up with is to have a separate optical viewfinder, so that I can track the subject without any lag or stabilization. Ideally such a viewfinder should be mounted on the hotshoe. But searching around on the Web, it seems there aren't many reasonable products for this application (e.g. Olympus-specific wide angle viewfinder, >100 USD), and it seems not many people have considered using an optical viewfinder for video recording.

My question is, how would you approach this problem?

Answer

I have a similar problem with my astrophotography setup in that sometimes it's difficult to see where I have my piggyback camera pointed in the sky. In stargazing circles, there are "unity" finders which are basically a piece of glass on which a dot is projected, allowing the user to orient the view at the sky with no magnification. These are called reflex sights or red dot finders.

I was looking for something that could attach to my camera to allow me to use my existing red dot finder. I found this product for sale and it met my needs:

http://www.photosolve.com/main/product/xtendasight/index.html

The product was actually marketed for the sports shooter that needed to get quick orientation. It may work for you. It's worked very well for my use.

edit: the advantage of the red dot finder is that there are no paralax issues because the dot still shows where you are pointed, even if your eye is off center. This should help with video work when your head has to move around as needed.

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