[Katy Penland]

I hope it's okay to ask about a film camera here.

Basic dumb question: Is there any focal length gained by using a teleconverter with a wide-angle lens? I'd love to use my 1.4 Tamron teleconverter with my 24mm Canon lens but I was told decades ago that they "don't work" with wide angles. I use the 1.4 all the time with my 70-300mm Canon IS zoom and it's great. I could just slap it on there and try it but I don't want to unwittingly wreck something in the process and thought I'd ask for advice first.

Thanks in advance!

[Adey Baker]

Why would you want to?

The main 'mechanical' problem could be that the rear element of the lens and the front element of the converter would come into contact if either/both protrude from the main barrel of the lens - this should be obvious to you before you attempt it!

If they fit together OK then the main 'optical' problem could be vignetting - this could be image cut-off resulting in clear-cut dark corners or even a circular image.

There's nothing much you can do about this, but more likely it will be uneven light-distribution, resulting in darkening towards the edges of the frame, in which case 'stopping-down' the aperture to F8 or F11, say, may improve matters and make the best of the optical defects which may occur.

Basically, you're increasing the focal length to about 34mm via a less than ideal route, so if you've got something like a 35mm-70mm or 28mm-80mm zoom lens this would be much better

[Katy Penland]

Originally Posted by Adey Baker

Why would you want to? ...

... Basically, you're increasing the focal length to about 34mm via a less than ideal route, so if you've got something like a 35mm-70mm or 28mm-80mm zoom lens this would be much better

Right, that's what I was trying to do is get just a bit more length out of my shortest lens. I don't have access to a camera shop before Monday (I live out in the sticks, literally), and my next lens is the 70-300. I was needing just a bit more distance for photographing a bird's nest before the kids fledged. Thanks for the tip about aperture to help with possible vignetting.

And thanks for the quick reply!

[Adey Baker]

I've just checked out my old equipment (!), if you'll pardon the expression!

I've got an old 'Komura' 2x converter for my Olympus OM system, which has the front element well recessed into the body to avoid any contact with the rear elements of any lens.

The 24mm lens fits OK, darkens somewhat through vignetting, but this seems to improve at about F8 (according to the rather dark focussing-screen when using the stop-down preview) and makes a more than passable 48mm macro lens as the minimum focus distance is about the same as my 50mm macro-lens.

The rather soft image towards the edge also sharpens up quite noticeably at about F8, also.

[Katy Penland]

Thanks for that, Adey, I'll give it a shot. I opted yesterday to use the 70mm end of the zoom for the junco nest, and even with the distance that gave me over what I'd've had with a 34mm, I managed to scare the babies out of the nest anyway. Damn. They can't fly but they could sure run behind another tree to hide. I slunk away as quietly as I could and hid in the house the rest of the day, I felt so badly for scaring them. I should have tried to find the nest earlier so they would've become accustomed to my voice and skulking around. Live and learn.

Thanks again for the tips. I'll shoot a test roll with the 1.4 on my 24mm, but I think I'll stick to things that I can't terrorize -- flowers, bugs, dirt......

[Jeremy]

Trying to photograph a small bird`s nest with a short focal length lens is irresponsible in the extreme! If you must photograph birds at the nest (not advisable unless you are very experienced and careful, which you clearly are not), you should be using the longest focal length lens at your disposal, and preferably a hide (blind in U.S.) to conceal yourself from the bird. The hide should be erected far away from the nest, and moved closer in increments, a bit at a time over several days. Alternatively, you could erect the hide at it`s final destination a bit at a time. No photograph is worth jeopardising the welfare of your subjects. Those young birds are probably dead now thanks to you; no doubt snapped up by a predator. Shame on you - you`re the kind of idiot that gives us bird photographers a bad name!

[Katy Penland]

Yes, Jeremy, thank you for the sermon from the mount. I did learn my lesson, the fledged birds aren't dead, and in fact both are doing just fine and in our yard every day. I'm sure every photographer of every level of experience, pro or amateur, has done something stupid at least once in his or her life.