DSLR Photography Forum

it's the GAS again.
I keep having to remind myself that I shouldn't shop when I've got no income, it's dangerous
was just looking at the Canon 1.4x extender and the Kenko 1.4x extender, the price difference is quite big! but I see a low priced Kenko 1.4x extender in another forum (and got me interested again )

Has any used these? Is the quality difference between the two very noticeable?

thanks

The one you want is the Kenko Pro 300 DG. Do not get the cheaper model. This one is about US$100 less than the Canon.

The Kenko Pro is more versatile than the Canon in that it can be used on more lenses - the front element sticks out less than Canon's.

I've heard AF is not a problem, but of course you won't get AF if your lens is slower than f/4, unless you are using a Canon pro-level D/SLR. You lose a stop of light with the teleconverter, so your f/5.6 lens becomes an f/8 effectively, and AF won't work.

Thanks for the information slej
My friend lent me his Canon 1.4x for a week, so I'm testing it at the moment.
Turns my 70-200 f/2.8 lens into a 98-280 f/4 lens, so I get that extra 80mm,nice to play with, but keep thinking whether it's really necessary (I'll find out when I find the need for one) at the moment I think it's a GAS thing, but, will see

and I found some dust inside my lens that wasn't there before but it doesn't show up in the pic, so its ok! I'm not sure how it got in there because I keep my stuff nicely o well~

If I like the 1.4x converter, I'll probably go for a Kenko one then, seems a lot cheaper than the Canon!

I'd be considering e-bay for a Canon personally.

I have the Sigma and find it excellent.

wow Adam... what a coincidence!
My Kenko 1.4 (Pro 300 DG) arrived just last Thursday!

I did have a bit of a play with it last week - but only for water polo action stuff where it wasn't as useful as I might've hoped. I say that not because I have found any problems with the teleconverter, simply that for indoor sports a 135mm f/2.0 lens was far more useful to me than a 190mm f/2.8. If I had the chance to use it for some outdoors games then it would've got a lot more of a workout.
The one thing I *did* notice about it however was that 1.4 tele has more effect than I first thought. When you see comparison shots taken with a "bare" lens and then taken with a 1.4 teleconverter, I always thought the effect wasn't very dramatic. But when I was actually shooting water polo with it, all of a sudden it felt like a MUCH longer lens. I was really quite surprised at the difference in the feel of the lens with a teleconverter fitted.

In my very brief experience so far I have nothing really bad to say about it - but I've done absolutely NO test shots or any kind of comparison shots. I'm happy to snap off some test shots in the next couple of days and post them here for you though. I'd be interested to see for myself anyway.

A couple of minor points I wasn't aware of until I had a play with it include:

1. It does work with (and autofocus with) my EF lenses (50mm f/1.8, 135mm f/2L, 70-200 f/4L), but the aperture remains below f/5.6 anyway so I wasn't expecting problems.

2. It does NOT work with any EF-S lens. No biggie for the kit lens, but there might be times when it could be handy to extend the range of my EF-S 17-85mm zoom (even though at the long end it would have a max aperture of f/8). Still, the Canon teleconverter won't work with EF-S lenses either.

3. It does work with my Sigma 10-20mm lens, but only when it is switched to manual focus. If you switch the lens to autofocus then the camera just locks up and you have to switch it back and switch the camera off and back on. Not that I have a need for a teleconverter for a 10-20mm lens, but I'd check out its compatibility with other Sigma lenses before buying if you intend to use them.

4. When used with lenses that support the genuine Canon teleconverter (that have 10 contact pins) the Kenko will adjust and report the "correct" EXIF data to the camera. So shots from my EF 135 f/2 get reported with a focal length of 189mm and f/2.8 when wide open. But when used with other EF lenses which weren't built to support the Canon teleconverter such as the 50mm f/1.8 (which only have 7 contact pins) then the camera still thinks its shooting at 50mm and f/1.8. Because the light metering is TTL then it still meters correctly, but it might be misleading if you rely on EXIF data, and could potentially upset flash metering.

But it seems nicely built, and despite the slightly daggy styling I'm quite happy so far
I've now got my eye on the Kenko 2x converter, and possibly their extension tubes too if/when my budget allows me.

I'll post some pics soon if you like!

Cheers
Adrian

Thankyou very much for the replies, and the points by Kombi
I'm still not sure how 'telephoto' the 200mm really is (haven't used it *that* much), so when I put the 1.4x on, I couldn't really tell from the look that it was more, when it was.
I think that getting the longer focal length from existing lens is a good idea, as I won't have to buy and carry around a longer lens, and I don't know how often I'll be needing anything more than 200mm.

The Kenko (as well as Sigma!) sound good, and the Canon also, since it's the only one I've used. It sounds like the Kenko functions similar to the Canon, and for those *few* shots requiring more than 200mm, I might go with the cheaper option.. the Kenko, maybe the 1.4x then the 2x (to get 400mm). then they can be stacked as well right?

then I think I should get out and shoot more rather than spending so much time looking at gear
and the extension tubes too!! :O for doing macro! sound good also!!

Adam - I would seriously advise you not to stack teleconverters unless you are absolutely desperate. The resulting loss of light and quality would not be worth it.

Even a 2x teleconverter is really not worth it - but maybe I am too much of a perfectionist.

Cheers,

Chris

Thanks for the advice.

Adam, I took a few test shots with the Kenko Teleplus Pro 300 1.4x today and here are the results:

Firstly, a comparison shot to see the magnification difference the 1.4 teleconverter makes. Both of these shots were taken from the same spot with the EF 50mm f/1.8 lens @ f/2.5 (which was wide-open with the teleconverter). Can you pick which one I used the teleconverter with?



For the next test I used my 70-200 f/4L lens (running at f/5.6 so I could use the same aperture with and without the teleconverter). In this scenario I positioned the camera on a tripod and took one shot at 100mm without the teleconverter, then the same shot at 70mm with the teleconverter to give the same equivalent focal length (70 x 1.4 = 98mm). This image shows 100% crops of the centre of the image, with a little inset pic showing what the whole photo looked like. Can you see any difference between the shots? The only differences I can see are very very minor, and could be accounted for by slight vibrations through the tripod or differences in focus. I was very impressed with these results.



And my final test was using my 135mm f/2L lens (at f/2.8 to ensure aperture consistency). Again I used the same subject and a tripod to shoot with, but this time I took one shot with the teleconverter fitted, then removed it and moved the camera closer to the subject until the subject was back at the same size in the frame, and took another shot without the teleconverter.
The results in the centre of the frame were very similar to the shot above, but this time I decided to take a closer look at the edge of the frame to see if there were differences. In this case the teleconverter does degrade the image quality noticably at the edges, but they are still perfectly usable.



Remember these are 100% crops (the inset shows the whole shot), and to be honest this corner example with the teleconverter is still noticably better than the corners of my EF-S 17-85 when it is at a fairly wide focal length.

So is it better than the Canon teleconverter? Well.. I've never used the Canon converters so I'm stabbing in the dark a bit here...
But I'd expect the Canon to have better quality at the edges, but really I can't see how the Canon could improve much in the centre of the frame because the Kenko seems extremely good there.
The Kenko also scores points for being usable with lenses that the Canon and Sigma won't work with... It allows the camera to attempt to autofocus beyond f/5.6 (although there is no guarantee it will actually lock focus), and big points for costing less than half the price of the Canon and is cheaper than the Sigma too.

I *think* these same teleconverters are sold as Tamrons too... just under a different badge.
(http://www.amazon.com/gp/product/B000068...oding=UTF8) :/ I can't confirm that though.

I'm cut... by the sharpness of your 135 f/2L at the corners heheh
Thanks for showing the results of the test Kombi (of a Kombi!)
The results of the Kenko teleconverter look perfectly acceptable to me; The degradation in quality is not obvious unless I'm looking at the 100% crop closely; (most of the time I resize my pics to post on the web anyway ) and not knowing exactly how much I'll have it on, it's probably better that I go with the cheaper Kenko than Canon. The price difference to me, is very big and I'm not sure that I'll pay so much more if the Kenko's already quite good.

Thanks!