18-1000mm f/2.8 Parfocal Zoom

P

Paul F

Veteran
I bought a Canon 9-500 f1.7 parfocal lens just for the heck of it. Since I have a micro-4/3 camera, I needed to use the 2x extender, making it an 18-1000mm f2.8 lens. It originally had auto focus built into the lens (no camera control needed). While this one is manual, the can be equipped with servo zoom and servo focus. I stripped off all the electronics. It is still a very heavy lens.

I had to buy a Vinten head that is made to support these heavy lenses and the manual controls. This is not a cinematographers lens by any means. No focus ring, no zoom ring, no iris ring. These are controlled by either by power or manual external control.

I took this first shot just to try it out. The optics were not quite aligned to the lens as it does not have a solid mount. The lens has no flange or threads to attach the camera. So I had to align it by eye and it was not centered well.

Its a fun lens but its a bugger to set up. Between the lens and the head, it is over 50 lbs.

It's interesting to note the optical distortion from heat waves even though it was about 50F outside.

The front element has an 8" diameter.

Keep your eye on the green parking sign as it zooms out.
http://www.youtube.com/watch?v=_4-d12E30s4

Here is another example - the cars in the opening shot are 2 miles away. The 45 mph sign at the crest of the bridge is over 1 mile away.
Its jumpy because the rig is so clumsy. Backfocus was off on this shot.

http://www.youtube.com/watch?v=NKA1JyzM4GY

I know the shots are terrible, but I though there might be some interest in seeing such a big lens. These lenses come up on ebay once in a while. Sometimes cheap.

Its one ugly lens with the box removed.


AF-100Canon18-1000mm_zpsa4399654.jpg
 
Oh man, you need to pick up a GH2, so you can then additionally use ETC mode, which would give you 36mm to 2000mm at f/4.
 
Very interesting!

But it won't be a 2.8 with a 2x.... more like a f/3.3 if I am assuming it's a two stop loss from f/1.7... F/1.7 is a half stop slower than f/1.4... thus a F/3.3 is a half stop slower than F/2.8.

But, as a guy who takes apart lenses and builds new ones (usually much worse than it was) I can appreciate this monstrosity very much. I think it is very cool!
 
atarijedi said:
Oh man, you need to pick up a GH2, so you can then additionally use ETC mode, which would give you 36mm to 2000mm at f/4.
Click to expand...
The f-stop doesn't change because of ETC. It'd be the equivalent focal length of 36-2000, but the f-stop would still be f/2.8 (or 3.3).
 
Ryan Patrick O'Hara said:
...

But it won't be a 2.8 with a 2x.... more like a f/3.3 if I am assuming it's a two stop loss from f/1.7... F/1.7 is a half stop slower than f/1.4... thus a F/3.3 is a half stop slower than F/2.8.
Click to expand...

My error Ryan. The f2.8 with the doubler is a published specification from Canon. I guessed as to what the non-doubler f-stop was when writing this. I was wrong. it is f1.4, not f1.7 without the double. Good catch.

As you can see from the picture this rig is really hacked together. The camera plate has cereal box cardboard stacked up to get the height right. The tripod handle is held on with a clamp. Hardly a proper rig. But I just wanted it together enough to try it. The aperture control is a real hack. It must be controlled by a motor. So I had to hook up a 9v battery, a up/down switch and a pot to control the speed.

I was surprised to see such a rough casting for the lens. But it doesn't matter if no one is supposed to see it. By the way, the wide part of the lens is not a lens hood. The front element is all the way to the front of that casting.

If you look closely, you will see that the lens (the light rectangular thing left of the black lens is part of the lens) is hanging off a plate (the thin light thing to the left of the lens) and the thin vertical plate is bolted to the head plate. The lens just hangs, all 40 lbs of it, off a small hanger.
 
Zoomed all the way out to a standard OTS shot, then a slow pull back to an ots of a sniper getting ready to shoot from a half mile away. (action shot of the year, Come up and get your oscar.)
 
Good warning. There are some other things you should know before you buy.

If you buy this lens, it is missing the rigging for focus and zoom. This is not unusual. They are often sold separately. They come as servo or manual. Manual can set you back a few hundred dollars. Servo can cost nearly $2000.

They make that statement about spare parts because there is no way to check out the electronics without a camera or test bed. The one I bought was similarly noted. But its easy enough to check the optics for scratches, dust, and fungus. When I bid on mine, I asked about the optics and they said they were clean, which they were. These boxes have a lot of electronics for the auto-iris and auto focus and some other things. But none of it is needed except that the motor for the iris needs to be working. It certainly isn't something to bid on for the casual user.

As to the mount, take a look at the 6th picture. The piece of metal at the top with the 5 screws in it is the mount. There is a guide pin between the 2nd and 3rd screw and also a larger guide pin at the bottom.

That piece of metal is cut at an angle on the back side. It mates with similar (upside down) piece of metal with the same angle cut on it. It just hangs on the camera off that piece of metal, with the pins preventing it from lifting off and falling off.

If you look at the picture in the first post, you will see a 1/4" piece of aluminum plate behind the lens. That plate is connected to two pieces of aluminum that bolt to the Vinten head plate (see the curved metal with the 3 diagonal lines on it). There is a hanger at the top of that 1/4" plate that the lens is hanging on. Nothing else supports it. It just hangs there. If your not up to fabricating your own mounting plate, I've seen mounting plates come up for auction that are designed for using this lens with smaller cameras. But that mount sells for $1500!.

So it's not so simple as spending $500 on the lens.

[edit] You are probably asking about the mount at the back of the lens barrel It looks to be a B4 mount which is the most popular for these type of lenses.
 
Last edited:
You must log in or register to reply here.
Back
Top