Quality of x1.4 or x2 convertors on Canon 100-400 IS L ?

Hi All,

Can anybody who has both convertors and used them with this lens give me an idea of the quality drop with both.

I actually need something like a 1400mm lens for the shot I'm after (rare birds of prey on their nest 300ft up a rock face), but I'm happy to have less as long as the quality of output is good enough to enlarge afterwards.

I.e. x1.4 isn't enough but x2 is bound to give a bigger drop in quality. Compromises have to be made I guess.

Anyway, experiences welcome.

Cheers

Ian

Thanks, Ian

I'm ordering a 100-400 L this week and I was wondering the same thing.

If anyone could point me (us?) to some examples it would be appreciated as well.

Thanks!

I have the 1.4X for the 100 -400 L

I don't have any image samples as I don't use it much - I have taken pictures with it but I would have to read the EXIF data to be sure which ones. To make a fair comparison I would have to shoot the same thing twice in good light etc etc and I certainly haven't done that.

I assume that you know that it disables the autofocus, you have to focus manually. I believe that there are two contacts that you can cover to stop this happening but have never tried and don't know which two.

AS far as quality goes it is not as good as the plain 100 400 obviously, but it is not horrible. On my D30 (3 million pixels) the pictures are sometimes acceptable but never brilliant.

However you are usually using it to photograph a tiny thing which is a long way away. The minimum aperture is something like f8, so you are at risk of camera shake with such a long lens as you don't often get 1/1000 f8 days (around here anyway). Therefore the final image quality is affected by shallow depths of field and camera shake or using high ISO settings anyway, so any reduction in optical quality from the converter is probably not the main worry.

Anyway unless you can afford a 600mm L lens what other choice do you have? The converter represents no more than a reasonable chance of getting a pretty fair shot, but its still better than no shot at all.

On the f/4 Yea probally would disable auto-focus, but not on the f/2.8 lens. The 100-400 is a f/4 over all lens right? Becuse if thats the case, I dont see a stop and a half ( caused by the 1.4x where as the 2x is 2 stops of light ), peeking over where you cannot focus. But I guess it depends on the body too.

The 100 - 400 is f4 -5.6, but the converter actually stops autofocus from working at all. It has some kind of connection that tells the body that the lens is not autofocus so it doesn't even try.

Hrm thats a bit unusual. I wonder if the teleconvertors enable auto-focus if it detects like a 2.8L as opposed to the f/4 and higher. Cuz I know you can focus with the teleconvertors canon makes, but not sure which lens I've seen it done on.

The autofocus is disabled on any lens where the 1.4x or 2x would make the effective aperture smaller than 5.6. This is true for all bodies except the EOS 1V, EOS 3 and I'm assuming the 1D and the 1Ds.

It seems like 5.6 is the minimum aperture that autofocusing can occur with any the "lesser" EOS cameras.

Of course, there's the old tape trick which will fool the camera but in anything but the really good and bright lighting, the focusing will be very eratic at best.

I've tested a 2.0x with the 100-400 lens and am quite disappointed with it. I've found the 2.0x photos very soft and have quit using it. Upsizing a straight 400mm photo gives better results than any sharpening I can figure out with the 2.0x tc in the equation.

My test was at a new wooden fence. I was at about a 30 degree angle to the fence. I taped a black piece of paper on part of the fence and focused on that. Tried a couple of different zooms with the 2x on and off. Nothing with the 2x looked very good. (Everything was on a tripod with a cable release on a bright sunny day, 10:00am, sun 90 degrees to the side of me.)

I took the shots at a 30 degree angle to the fence to see if anything was in focus, not just what I was aiming at. Nothing in the frame was sharp, so it wasn't just a focus problem. My opinion is that, perfectly focused, it's not worth using on the 100-400.

A friend of mine tried it on his 70-200 f/4 lens and like it a lot, though. So it probably has a place. It's for sale if anyone wants to make a reasonable offer.

Ian, you knew I would turn up sometime

I have tested this combination and before you shell out the cash for the 2x, here are my findings.

Only use the Canon MK-II 2x TC. I tried a Sigma and Tamron and they were not as good as the Canon (which was the sharpest).

You will need a really good solid support. Even though IS will continue to work, it is the very small vibrations IS does not pick up that will magnify and give blur.

Use an anglefinder C (borrow if necessary) as you won't stand a snowball's chance of getting accurate manual focus without it. If you can't get an anglefinder, then make sure you 'bracket' the shots for focus.

The longest combo I can shoot out of my collection is my 500 with x2 and x1.4 stacked. With my 1D the AF still works, albeit a tad slower, and it is only just stable on my full Wimberley head. I once saw a newspaper PJ using the same combo hand-held - respect due.

Oh yes, I forgot, lock down the zoom. I had mine just on grip and it must have allowed more vibration in the lens body. Locking it down more firmly made a big difference.

Thanks everyone.

Kenny, yes, I was kind of hoping you would drop by...

The subject, is stationary (for the most part), so mounting the whole lot up onto the tripod, mirror-lock, cable release should give me a fighting chance.

I think I will try the Canon x2 and see what I get from it.

Mind you, I could buy a 100ft 12mm rope, harness, couple of crabs and a figure of eight and abseil down to the nest and use my 50mm lens.

(Note, I wouldn't condone this of course, I was joking, thought I had better put that in before someone goes off on one).

Cheers

Ian

I'd like to ask a different question on a related matter. When using the 1.4X II with the 100-400, I noticed that focus confirmation light does not come on when focusing manually as it does when using the extender with, say, the 70-200 f/2.8 in MF mode. Is this normal?

According to Canon's specs, AutoFocus doesn't work with either extender on the 100-400 lens. I believe it's caused by the most wide open aperture being reduced to below the threshold for AutoFocus to work. The 1D and Mark II work better than the 10D. The 1.4x will AutoFocus sometimes if you tape over a couple of the contacts. The 2.0x will AutoFocus less than 10% of the time on a 10D using that technique (according to my own experiments).

Also, I've read comments that if you tape over the contacts and try forcing AutoFocus to work in too low a light setting, your AutoFocus motors in the lens will burn out.

It should always work with the 70-200 f/2.8 since you're only at f/4. But on the 100-400 you're now at f/8, over the 10D limit of f/5.6 for AF.

But you probably already knew that.

For me, I find the 100-400 + 1.4 TC to be hit or miss with the confirmation light. I don't trust the focus confirmation light with this setup anyway (from some tests I did last week on a cormorant). It's VERY difficult to manually focus the 100-400 + 1.4 on a 10D unless you have great light and/or eyesight.

I did love KennyG's suggestion about the Anglefinder C though. Since it's got 2.5x magnification it would help a lot with manual focus on this rig. Another reason to spend more money....

Autofocus works with the 100-400 and the 1.4x, it does not work with the 2x. I use the 1.4x all the time, rarely use the 2x.

Which camera?

And did you tape the contacts?