What a minefield this area is. You know the things, bits of glass we screw to the front of our fixed lens consumer cams to extend the focal length at either end of the scale.
There may well be a guide here somewhere about them, but that's not quite my point in this post. I want to talk to you about three particular lenses, and how they've worked for me.
I've mentioned here enough times already that I'm building a time slice rig, so I've bought twelve used cameras, choosing the Olympus E-10 and E-20's as being the right quality at a price I wanted to pay. My point is that some of these cameras came as kits with accessory lenses, always the same lenses, and with some simple fiddling fitting these to my video cameras has been something of a revelation, because of the price!
I would say that as a long time still photographer it becomes clear pretty quickly that the lens is everything. The fancy body of an SLR does nothing other than time the shutter release, hold the film in the right place, house a light meter which may or may not be useful, give you a way of viewing the subject through the 'taking' lens, and give you something to hold on to.
The fact is that if you buy the latest all singing all dancing digital do-wacka-do SLR and put the end of a beer bottle in front of it your are wasting your time.
When it comes to this firmly amateur end of the video camera world it strikes me that there is a surprising under emphasis on the still present need for decent glass up front. I can recall some twenty years ago a pro videographer showing me his cameras which had plastic lenses! Accompanied by the statement that 'it's just not the same league as still cameras'. That might have been true in the old Video8 or Hi8 formats, but these days the cameras are on a par with quality medium range still cameras in resolution, so now more than ever quality optics need to be the order of the day.
When I bought my first digital8 cameras a few years back I immediately went on the hunt for accessory lenses, particularly wide angle ones. I went through about six of them before it became apparent that, quite rightly, you're going to have to part with serious money to get something that will not degrade the image at all. The best I ended up with was a Sony VCL HD model, that cost me half the price of the camera. Now that's not unusual, in the old days parting with two grand for a telephoto lens for one of my Nikons was normal. But when it comes to video gear there's something of a sinking feeling when that 'quality' Sony lens has your image vignetted at minimum focal length settings. What?!!
In an effort to remove this problem I lashed out on a century x0.7 WA converter. A nice piece of glass, that's heavier than the camera . So now I had a result. A focal length that didn't bend the image too much, stays sharp to the very edge, and allows the prime lens to zoom through it to infinity without losing the ability to focus, in case I should ever need such a thing.
So one day I'm sitting amongst my ever increasing pile of these accessory lenses intended for the Olympus E-10's, and me being me I dug around for some step-up rings to allow the 37mm filter thread on my cameras to take the 62mm they had, and lo and behold the quailty is indistinguishable from the Century! And they are lighter! But the best bit is that the smaller two of this range go in mint condition second hand for around £35!
So what are they all about?
Well, the Olympus E-10's in their day were considered to be a 'Pro' quality camera, they were about a grand when new. But the odd thing that distinguished them from others was that they have fixed lenses. No idea why that should be, I can say that it's proven to be a bonus in many ways, but without the ability to swap lenses Olympus had to do something special to extend the available focal lengths. And so the camera's from day one had three add-on lenses made for them which are optically matched, i.e damn good!
The 'shortest' is the WCON-08B. A phenominal piece of glass, fully coated on all sides, as they all are in the range, with a huge front element bearing a filter thread size of 105mm. This lens is so big it does not reduce the light entering your prime lens at all. It modifies your prime lens focal length by a factor of X0.8, and no vignetting.
There's a pic of one here, this is a lo res image: WCON-08B
Next in line is the short Tele version, the TCON-14B. Muliplying the prime lens focal length by, you've guessed it, 1.4, it also does this without any loss of light, which is remarkable. The image of the 08B above was taken with one of these lenses, here's one fitted to one of my Sony video Cams (in this instance with a Tamron lens hood, and the stuff on the LCD screen is a home made screen hood and magnifier):
Those two I can recommend whole heartedly, but if you want to push the boat out the next in line is the rather odd TCON-300B. This one needs some more application to make it fit a video camera, as it's so big that it comes with a special mount for the E-10. So I had to make up a fairly simple, but nonetheless accurate mounting plate setup to accomodate this lens. I don't think I can paste another image, but search google images for it and it will come up like a rash. This does stop the lens down a little bit, changing the E-10's prime lens of f2.4 on full zoom to f2.8. But that's still remarkable, to achieve that in regular interchangeable lenses you're talking telephone number prices. Yet again this lens is utterly superb, there is a faintest hint of chromatic abberation, but manageable. The down side of this particular one is that they tend to go for between £80 and £100 used, even more sometimes, I think this one seems more attractive to folk and they've kept their price better. I believe they were about £600 when new.
You can screw the TCON-14B on to the front of the TCON-300B with suitable step up rings, but the resulting image is not so good, lots of chromatic aberration and less sharp than each lens on their own.
Now I could show you some footage shot with these, in fact I already have in the thread about steady mounts for an aeroplane, but with compression being what it is, and with me still learning how to reduce file sizes in the best quality there's little point tbh. All I can say is that if the opportunity arises, have a go on one of the first two at least. You will not be disapointed. And if anyone wants to see how I mounted the big one let me know and I'll post a pic.