35mm adapter: exactly how much light will I need?
 

Everyone always says that 35mm adapters eat light. But exactly how much lighting am i going to need?? I am considering buying a brevis to use with my Canon A1, and i already have a couple of Canon FD lenses, a 1.8 50mm and a 2.8 28mm.

Exactly how much extra light will i have to throw at it to get good results? I will be doing some location work in my flat (apartment!) and have a 3 head dedo kit and a couple of 1k redheads, and possibly a 150W HMI fresnel at my disposal.

Would this give me a workable amount of photons?

Thanks!

Jim

James,

Those lights would do, in close quarters. What you should watch out for is balancing exposure between your 2 35mm lenses. you have to make them match, your 50mm is definitely a fast and bright lens, you might need to stop it down to match your 28mm.

Ted

James, you'll find that you'll need relatively little light added to keep the XH-A1 happy. I've shot a fair bit indoors with the XH-A1 using just window light and have managed to keep the cam locked at -3db with good exposure. The CF1L imaging element is what you need for that cam.

Dennis,

How many usabale stops should I expect to have when using a CF1 on an HV-20? Lenses would be Nikon AF f1.8 50mm and 85mm, and I can control the lighting.

Thanks much.

If you can light, f1.8 to about f8 would be quite safe. I rairly shoot higher than f8.

By "safe" do you mean safe from vignetting?

A combination of high aperture on the 35mm lens and the camera itself can lead to edge falloff if the light is not there to warranty the settings. Similar factors can contribute to a grain masking. The majority of adapter shooters are using their lenses either wide open or 1 to 2 stops closed to provide a more pleasing bokeh, so in most cases this is as closed down as you'll be. For maximum sharpness when using the HV20 with a 50mm f1.4 lens I shoot in the f4 range on both the 35mm lens, and the camera itself. Outside in sunlight, a 5 stop cut using ND filters would typically be required using the aforementioned settings.

Dennis,

You may want to clear up some confusion on the Cinevate forums concerning available F stops with the CF1.

I don't know if these difficulties are due to using the CF1 with a large camera, or some other reason like lighting.

http://www.cinevate.com/phpBB2/viewt...er=asc&start=0 (See Faisal Lutchmedial post June 14th, 8:39am)

Going with an adapter would be a great choice for the talking head interview portion of my documentary, but I need to know how many stops the $2,000 investment (adapter, FF, rails, lenses, montitor) will give me to work with with an HV20.

Thanks much. You've been a great help.