I have one of http://cgi.ebay.com/CANON-AE-1-CAMERA-WITH-50MM-F1-1-8-FD-LENS_W0QQitemZ7585604874QQcategoryZ107919QQrdZ1QQcmdZViewItem these. I want to use the 50mm lens on it for a Letus35.

The problem is, I can't seem to get the aperture to stay completely open when it is off of the camera. It closes itself down. Rotating the aperture ring while the lens is off of the camera doesn't change anything.

Does anyone know a lot about Canon FD lenses? In addition to the f-stops of 1.8-22 there is an A. Automatic? This is confusing, since it's suppose to be a manual lens.

Can anyone help me?

Bryan,

the FD lenses are fully mechanical lenses. The aperture is closed by a spring inside the lens. At the base of the lens (where the lens is connected to the camera body) there is a pin or lever (I don't have any FD lenses, so I don't know how it looks exactly). When you push this pin or lever, the aperture should open. In order to stay open you have to fix the pin or lever in that position.

If you do this with some care, there is little risk to damage the lens.

http://omnibuilt.com/sa/fe_1_b.JPG

This is what the bottom of my fd lens looks like.

The lever at the top of the picture doesn't do anything when I move it. The one on the right won't budge. The button looking thing in between won't do anything, and neither will the one between the top lever and the red dot.

I can not figure out what I am suppose to do to open up the aperture.

Bryan,

which f-stop is indicated on the aperture ring? Try to set the aperture ring to f1.8 and then try to move one of the levers. If the aperture ring is set to "A" (this is indeed for Automatic) then you probably have to push a small knob on the aperture ring to unlock the automatic position before setting the aperture to f1.8.

Hope this helps.

I have tried doing this at both f1.8 and A. Neither seem to allow me to open the aperture.

Sorry to hear that, Bryan. In that case I'm afraid I don't have any more ideas. Perhaps someone who owns such a lens can help you.

Got it working. It had to be both mounted to something, and have the aperture lever held back. I held the lever back, then mounted it to my letus 35, and all is well.

Hi Chaps just got a Fd lens to EF body adapter for my XL2. First impressions are excellent. Thanks for the tip on mounting the Fd lens

Rod C

Question regarding the use of SLR lens as front element on Letus35

Say, the day is sunny and you don't want your 35mm adapter's matte screen to bloom.

You have to limit the light that falls on it then.

There seems to be 2 ways of doing so:

1. Using the 35mm lens's aperture ring

2. By attaching a ND filter to the front 35mm lens.

# 2 is rather obvious, but requires buying/hauling around ND filters.

# 1: won't work on Canon FD but will work on Canon FL lenses, supposedly? Is this true? Also, if we change the aperture of the front lens, won't it also affect the DOF (increase it, killing the 35mm adapter effect) right away?

Question regarding the use of SLR lens as front element on Letus35

1. Using the 35mm lens's aperture ring

# 1: won't work on Canon FD but will work on Canon FL lenses, supposedly? Is this true? Also, if we change the aperture of the front lens, won't it also affect the DOF (increase it, killing the 35mm adapter effect) right away?
Hi Alex,
1. An FD lens will also change aperture like an FL lens if the FD lens pins are pushed correctly by the adapter.
2. The selected aperture in the lens forward of the ground glass will affect the DOF because it works like an ordinary camera projecting the subject on the GG instead of a film.
The aperture in the lens behind the ground glass will not affect the DOF because it only sees the flat picture on the GG.
Hopes this clarified it a little.

Yes, thank you.

Bryan, I'm not sure how to "hold the aperture lever back" before mounting FD lens on my Letus35A adapter? Simply mounting the lens disables aperture ring, period.