Optics question...

MainFragger

I've been looking, but never really saw this directly address anywhere...

I know there are wide zoom lenses. But my question is...what happens when you mary a wide angle lens to a long zoom lens on your own? (Assuming of course that they lens would fit).

Will the apparent depth of field at equivalent value at full zoom with a wideangle attachment be deeper than if you were shooting straight telephoto? For example...lets say you zoom into something at a zoom of like 432mm. A .8X wide angle lense would bring you to 345mm/346mm.

Would 345mm natural zoom, have the same depth of field as 345mm that is the result of a wide angle lens on a 432mm telephoto?

MainFragger

Shay Stephens

Not having tested this directly, I can only offer a guess here. But my thoughts are that you would see no benefit, and most likely, you would get image degradation.

Well, I have to take that back, I do remember doing this with a Sony 707. I had a .8x wide angle on and not remembering I had it on, I zoomed the camera to 190mm. The resulting photo was disappointing from an image quality standpoint. I vowed after that to only use the .8x while the camera was at full wide angle. If I had to zoom for framing purposes, I would take the wide angle off.

Also, depending on the lens and the configuration, you could end up with really bad vignetting too.

So if you already have the lenses, go ahead and try it out, but if you are planning on buying the lenses to do this, I would not buy them for that test.

MainFragger

Well...

Shay Stephens wrote:

Not having tested this directly, I can only offer a guess here. But my thoughts are that you would see no benefit, and most likely, you would get image degradation.

Well, I have to take that back, I do remember doing this with a Sony 707. I had a .8x wide angle on and not remembering I had it on, I zoomed the camera to 190mm. The resulting photo was disappointing from an image quality standpoint. I vowed after that to only use the .8x while the camera was at full wide angle. If I had to zoom for framing purposes, I would take the wide angle off.

Also, depending on the lens and the configuration, you could end up with really bad vignetting too.

So if you already have the lenses, go ahead and try it out, but if you are planning on buying the lenses to do this, I would not buy them for that test.

I would assume distance between lenses would be an issue. A wide angle lens is meant to be put on a wideangled camera. As you zoom out the distance between the lenses is going to change, and you are gonna end up blurring the image. I understand that much. But if you could then readjust the wideangle lens to fit the new position of the zoomed lens to maintain the proper focal points...what would be the effect. And doing this on a 707 (or most if not all cameras) would probably get bad results if you didn't do that. But I was thinking ideals distances and settings.

I do not have a rig I can really try this with right now...but I was curious for my own knowlege (because eventually I will).

MainFragger