Stepper rings before wide angle lens: A field of view question.

[masher 1]

By popular request...

Has anyone experimented with using extra rings to change the distance of the (wide angle) lens from the camera? I've heard that it can make a difference (increase) in the field of view.

Mind you, this was just from one source, and I haven't tried it.


Edit: Speeling....

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Arching is overrated - Marlies

[quade 3]

Adding rings -should- create more problems than they would "solve".

Adding rings may cause vignetting in the corners.
Adding rings -probably- will have the effect of narrowing the field of view, but that will depend on the exact design of the lens.

quade -
The World's Most Boring Skydiver

[GravityGirl 0]

Sounds like it might cause vigneting, but I have some in stock, so I'll throw a couple on my camera and check it out this weekend.

~~~~~~~~~~~~~~~~~
Peace and Blue Skies!
Bonnie ==>Gravity Gear!

[masher 1]

I was referring to this statement on the Way Cool website:


If you use the 37mm Red Eye or Blue Eye with a step ring down to 30mm you will get a slightly wider image. This is particularly useful on the newer model Sony PC cameras which are reported to have a more narrow field of view off the shelf than their predecessors.

Note: Using this affect with more than one step ring will reduce image quality in the corners of the frame and lead to frame cropping.

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Arching is overrated - Marlies

[Squeak 17]

this is when using a BIGGER lens diameter than camera diameter so you are moving the WA away from the camera lens slightly BUT the lens diameter is bigger than the camera lens diameter so you dont get the vignetting.
You will however loose Focal distance (at least you do on stills camera). But since the wide angles are soo wide and the focal distance is very small to start with you shou8ld not notice too much, especially if you focus to infinity.

You are not now, nor will you ever be, good enough to not die in this sport (Sparky)
My Life ROCKS!
How's yours doing?

[WayCool 0]

The Statement on Our web site refers to our Red Eye lens only. It works to some extent with our Red Eye lens. It gives a wider field of view with that lens. I haven't tested the idea with other lenses though I think it would work. The design of that very wide single element lens is such that the image almost overlaps into the lens housing ie. black corners.

We are very soon to release a very wide lens which will be wider than the Red Eye and very small as well.

Stay Cool
http://www.waycool.com.au

[davelepka 4]

How does increasing the focal length widen the field of view? That seems contradictory to the whole premis of focal length. Just wondering..

[freeflyguy 0]

Works for me.

I have a Kendo .42 I think 47mm threads is the start, stepped all the way down to 30mm.

I have compared and it has the almost exact field of view as Max's Diamond .3

My lens is huge to start with though. Looks cool too. Like I am a real video guy.

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bzzzz

[Squeak 17]

Quote

How does increasing the focal length widen the field of view? That seems contradictory to the whole premis of focal length. Just wondering..

Think of it like a Funnell the W/A lens is much bigger than the camera lens in diametre

You are not now, nor will you ever be, good enough to not die in this sport (Sparky)
My Life ROCKS!
How's yours doing?

[davelepka 4]

I need some more technical info before I'll buy.

Using a ring will move the wide angle further from the camera lens, elongating the focal length.

There's a reason that a 300mm zoom lens is huge, the lens elements are 300mm apart. By contrast, when you move the elements closer together, such as my 24mm, the feild opens up significantly.

The 'step-up ring makes it wider' concept just doesn't seem right. There may be some other factors I'm not considering, but if you move lens elemnts apart, the field of view will be reduced, not increased.

[WayCool 0]

I can't give you the technical details you ask for. I just know what works. Try it!
I leave the technical optical design stuff to qualified specialist consultants.
Good luck with your technical info search.

Stay Cool
http://www.waycool.com.au

[jmfreefly 0]

Well, I haven't seen or played with this yet (but I do have waycool lenses en-route, and both a pc100 and pc9, so I can test) -- however, the key that I think some people may not be factoring in is that the lens is a larger lens, meant for a 37mm, and they are stepping down to a 30mm.. so there.

Again, I have no idea if this works as expected, but I shall see.. will post updates when I have the lenses.

[davelepka 4]

The diameter of the lens shouldn't be relevant in this situation. Take a wide-angle lens and look through it. Now move it away from your eye, and watch tht field of view get smaller.

The only possibility I can come up with may be that if when the lens is mounted with just a single ring, the camera lens is not wide enough to 'see' from inside edge to inside edge, and moving the lens out lets you see the full width of the inside of the wide angle lens. The caveat to this is that once you can see the full inside of the lens (vignetting) you'll zoom the camera lens forward to cut out the corners from your image, thus nullifying (or greatly reducing) any advantage gained by the additional ring.

If this is the case, it's important that people understand that the effect if the result of poor matching of components, and that it is contrary to the pricipals of optical physics as it relates to focal length. Furthermore, the increased exposure of your lens to risers and lines (as a result of sticking further out) and the increased leverage your lens will have when it tries to rip the front of your camera off, would probably make this a bad idea.

If you want to see more, fly yourself 10 inches further away from your subject. If your flying isn't that finely tuned, the 'parlor trick' with the lens won't mean anything anyway, I think...