Extender XL 1.6x: How well does this work?
 

An EXTENDER XL 1.6x is included in the new brochure for the XL2.

It sells for about 350.00 and magnifies the image 1.6 times.

My questions:

Has anybody out there used it?
Does it achieve the magnification optically or digitally?
Does it hurt quality of the image?

I use longer focal lengths to help reduce depth of field, and I'm really curious to see this device combined with the 20x lens on the XL2.

Thanks

Steve Mims

Steve,

I have not used this extender, but I've used an extender on still cameras. An extender is an optical device that goes between the camera body and the lens, so the magnification is optical.

Image quality will always suffer a bit, but it depends very much on the quality of the extender. It might well be that you don't see any difference.

An extender won't help in reducing the DOF because the effective aperture is reduced when you use an extender. A 1.4x extender reduces the effective aperture by 1 f-stop, a 2x extender by 2 f-stops (if you use a 2x extender on a lens with a max aperture of 1.4 you end up with 2.8), so a 1.6x is somwhere in between.

Steve

I have the 1.6 extender which, as Rainer says, is optical. I think image quality holds up pretty well with the regular x16 XL lens, although I haven't done any critical tests.

However, the x20 lens is said to have significantly better glass than the x16 so, unless Canon produces a new x1.6 "L" extender, it may cause more noticeable image degradation.

Regards
Duncan

DOF will drop, because the focal length is also increased. A lens with a TC takes on the characteristics of a prime with the same specs. For example a 300mm f/2.8 with a 2X TC will have the same DOF as a 600mm at f/5.6 Use a DOF calculator to determine the exact amount, but usually the DOF is about cut in half. However, if you move the camera in relation to the subject (to keep the same framing, subject size etc. the same), increasing the camera to subject distance will increase DOF and you will end up with the same DOF.

Thanks to all you guys for the clarifcation about this extender.

Working at the long end of the lens at 16x I am currently able to significantly roll the background out of focus, and I'm excited about trying the same technique with the 20x.

I'm glad to find out that this device(XL 1.6) is optical and that any degredation of the image won't involve pixels. Also, it does make sense to me that as the effective focal length increases, the lens speed goes down as well(so that effective iris opening is smaller). I see this all the time working at longer focal lengths, however the depth of field continues to fall compared to the shorter focal lengths.

In any case, I'd love to test the new lens with and without the extender to see what price, if any, you pay for using it...besides having to move the camera into the next county.