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cipriaa Dec 28, 2014 11:03 AM

Lens mount adapter
Hi. My name is Anthony and I am new to this forum. My son gave me a Fotodiox Lens Mount Adapter for Christmas, because I have an old, inexpensive Vivitar wide angle lens that I used to use with my original SLR, a Canon A1. When I bought my Nikon D50 Digital SLR, of course the Vivitar did not fit. The cost of new wide angle lenses was prohibitive, because I don't use one extensively. Still, I miss having it on the few occasions where it would be appropriate.
So, I mounted the lens onto my Nikon D50 with the adapter, put the Nikon in Manual mode, and took a few pictures of a Christmas tree. Here is what happened:
1. First, the images in the viewfinder did not appear to be wide angle.
2. The images on the camera viewing screen was black
3. When I viewed the pictures on my PC, there were only very faint images of the lights on the tree. Everything else was black.

The adapter was bought through I looked at it on their site and read some of the reviews, which were mixed, but there was at least one reviewer who used it successfully with very old lenses. (At first, I thought perhaps that I couldn't use a lens from a non-digital camera on a digital slr.)

Then, another reviewer said that the adapter didn't work for his wide angle and fisheye lenses.

Do you have any input? I have been waiting for years to mount my wide angle lens on my D50.

Thanks a million.

JimC Dec 29, 2014 9:58 AM

Your lens is going to appear to be "longer" on a dSLR like your D50, since it has an APS-C size sensor (smaller than 35mm film). To see how angle of view compares, multiple the focal length by 1.5x.

For example, a lens with a focal length of 20mm on your D50 will have the same angle of view as a lens with a 30mm focal length on a 35mm camera (20mm x 1.5 = 30mm), or a dSLR using a larger 35mm film size sensor. That's why most "kit" lenses on a dSLR like that tend to start out at around 18mm (since 18mm will give you the same angle of view you'd have using a 27mm lens on a 35mm camera).

So, even though 18mm would be a very wide angle lens on a 35mm camera or dSLR using a 35mm film size sensor, it's not that wide on a dSLR like your D50 using a smaller APS-C size sensor.

So, a typical kit lens on a D50 (like an 18-55mm model) is designed to be an approximate replacement for a typical 28-80mm kit zoom lens on a 35mm camera from an angle of view perspective.

What focal length is this lens you're trying to use? Again, multiple that focal length by 1.5 to see what focal length lens would give you the same angle of view on a 35mm camera.

As for images being dark, you need to use what is known as "Stop Down" metering when using manual lenses on a dSLR via an adapter.

That's because there is no electrical connection (or manual connection designed to set the aperture) between the camera and lens using an adapter (so the camera has no idea what aperture is being used and is unable to set it).

So, use manual exposure, and set the aperture via the aperture ring on the lens versus the camera settings (where smaller f/stop numbers represent wider apertures that let in more light); and set the ISO speed to what you want (higher ISO speeds make the camera more sensitive to light, but can also increase noise levels).

Then, "half press" the shutter button to let the camera meter the scene. Then, adjust your aperture, ISO speed or shutter speed so that the needle/bar in the meter is centered to take a properly exposed image.

IOW, if the photo is too dark, you can either increase the ISO speed, or use a wider aperture setting (lower f/stop number using the aperture ring on the lens), or slower shutter speed (using the camera controls to adjust it when in manual exposure mode).

If the photo is too bright, do the opposite by decreasing the ISO speed, or using a narrower aperture setting (higher f/stop numbers using the aperture dial on the lens), or faster shutter speed.

Again, just "half press" the shutter button on the camera when in manual mode and look at what the meter is telling you (so you know if you need to use settings that give you a brighter or darker exposure), then adjust settings until the meter shows a properly exposed setting (needle/bar in the center of the meter scale).

It's not as hard as it sounds, as you can just twist the aperture ring on the lens to let it more or less light; or spin the appropriate dial on a camera to control the shutter speed for a brighter or darker exposure, until a "half press" of the shutter button shows a centered meter needle; using an appropriate ISO speed setting for the scene.

ISO settings on a digital camera work in the way different film speeds worked, where higher ASA/ISO speeds allow faster shutter speeds for a given aperture setting and lighting condition to get a properly exposed image, but at the expense of more grain (or what's referred to as noise with a digital camera). So, outside in daylight, something like ISO 200 is probably fine, or ISO 400 if you need a bit faster shutter speeds for some moving subjects. In dimmer lighting, a higher ISO speed may be needed so you can use fast enough shutter speeds to prevent blur.

With film, you'd have to use different film speed speeds (ASA/ISO 50, 100, 200, 400, 800 or 1600) for that kind of thing, swapping out to different film in different lighting conditions to balance shutter speeds needed versus grain in images.

With a digital camera, you can change the sensitivity with a camera setting for ISO speed instead.

So, depending on the lighting you're shooting in, with an appropriate ISO speed setup, just use the Aperture Ring on the lens to let in more or less light so that you get a properly exposed image, adjusting shutter speed as needed.

Again, if you "half press" the shutter button when in manual exposure mode, you'll see a meter in the viewfinder that lets you know if the photo would be underexposed (too dark, with the needle to the left of center), or overexposed (too bright, with the needle on the exposure meter to the right of center) with the aperture ring settings and shutter speed you're trying to use (so you an easily make adjustments to the exposure by twisting the aperture ring, or spinning the appropriate dial on the camera to use a faster or slower shutter speed, as needed for the lighting conditions).

Of course, you'll also need to use manual focus.

I'm assuming you have a lens with a focus ring and aperture ring (what you'd want to be using via an adapter for those instructions to work).

cipriaa Dec 29, 2014 3:05 PM

Hi Jim,
Thanks a million for all the information you gave me. I will try what you said, hopefully with good results. I didn't wait until after trying your suggestions to reply, because I'm not sure I'll find your post again as I'm having a little trouble navigating this site. Hopefully, I will find it and get back to you with good news.
I appreciate your input. Thanks again, and HAPPY NEW YEAR!!!.
Anthony (cipriaa)

JimC Dec 29, 2014 4:42 PM

No problem. I just changed your default profile options so that you should get an e-mail with links to any new posts made in threads you've participated in. So, that may help with finding any posts you've made, so you'll know when replies are made to them with links to those replies.

If you want to change it back so that you no longer get e-mail notifications when new posts are made to threads you've participated in, just click on the User CP (Control Panel) menu choice you'll find at the top of forum pages here, then click on the "Edit Options" link you'll see on the left side of the page under the "Settings and Options Section". Here's a direct link you can use to get to that Edit Options page:

You'll find a drop down menu in the "Default Thread Subscription Mode" on that page that lets you change if you get e-mail notifications or not (and they can be handy so you can see replies to threads with links to those replies in your e-mail in box).

You can also see posts you've made in the statistics section of your user profile (which you can see by clicking on your member name that you can see in the top right hand corner of the forums pages after you log in). Here's a direct link to your profile:

Or, just send me (member name JimC ) a Private Message if you have any problems finding posts and I can send you a link to them.

Let us know if you get the lens working OK (and it sounds like it's just a matter of using an ISO speed, aperture setting and shutter speed that lets in the right amount of light for the lighting conditions you're shooting in, so that you get correct exposure, as detailed in my last post).

cipriaa Dec 31, 2014 10:39 AM

To Jim C., re. Lens Mount Adapter
Hi Jim,

Thanks again for your reply to my inquiry about the lens mount adapter I'm using to attach my old wide angle lens to my Nikon D50. You asked about the properties of the lens. It is a Vivitar 17 - 28mm lens, f/4-4.5. Your suggestions about using a higher ISO and a slower shutter speed worked well so that now my pictures are properly lit.

Regarding the wide angle capabilities, no matter what I tried, I am not getting wide angle results. Ultimately, I am going to return the adapter to The only problem is that now I am having an extremely difficult time removing the adapter from my Vivitar lens.

Once again, I appreciate the time and trouble you took answering my post to this forum.

Best regards for a Happy and Healthy New Year.

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