I use a Kenko Pro 300 1.4X on my 70-200 f2.8 IS.It is OK wide open(f4) and improves greatly when stopped down.On sunny days,you'll have plenty of ligh to go to f5.6 or even f8.The Kenko has excellent IQ.
You just need to give it a try and see if the AF is fast enough for you to maintain the accuracy you're used to now with the XT and 70-200. I doubt the IQ will be the deal breaker.
You'll lose the ability for the camera to do high-precision AF. Plus there may be some slow down due to the camera getting a darker image.
I may be wrong but I think the slow-down is due only to the reduced light and contrast and not automatically due to the presence of a TC as is the case on the 1-series.
Apart from the slower AF the IQ should be no worse than resampling an image taken with the bare lens to achieve the same magnification boost. A decent 300mm lens will look better but is uneconomical if you don't need it much.
Unless you are buying mail-order you should be able to try one at the shop with your camera and lens to see how the AF speed is affected.
I nearly forgot to mention: The TC will turn your 70-200 f/2.8 into a 100-280 f/4. You lose the 70-100 range. The 100-200 part of the range will have worse IQ than on the bare lens. The 200-280 is a bonus. With a zoom more so than with a prime lens you get a mixed bag of pros and cons when using a TC.
BTW: I have found the EF 1.4x works well with the 70-200/2.8L IS. There are those here who do not recommend the combination but I can see no reason why not.
Was shooting Rugby Weds night with the 70-200F2.8IS and a 1.4x and i found the shots to be rather uninspiring. IT was dark and i was shooting at 1600 1/250th F4 @ 280mm on the 1dii but even still when they were in focus they were not amazingly sharp. Not soft but not sharp.
In daylight it will be much better but for night time stuff it's not the best.
Since I'll be branching out, it won't hurt to spend the cash on the 1.4tc. In the future, I'm sure I'll be buying a 300 and can use it with that if I have negative results with the 70-200.
I know.. the body is limiting me. I may upgrade that before the 300 comes along, well maybe.
I agree with Andrew's comments. I prefer to use the 300/4L IS (often with the 1.4x Extender), but I don't hesitate to use a 1.4x TC on the 70-200/2.8 L IS, when that's all I have with me.
chris78cpr wrote:
Was shooting Rugby Weds night with the 70-200F2.8IS and a 1.4x and i found the shots to be rather uninspiring. IT was dark and i was shooting at 1600 1/250th F4 @ 280mm on the 1dii but even still when they were in focus they were not amazingly sharp. Not soft but not sharp.
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At least a part of your problem there could be motion blur. Over the years and hundreds of thousands of frames, I've found 1/400 to be the absolute minimum for consistently getting reasonably sharp images shooting action sports. 1/320 and below and I start losing an unacceptable number to subject motion blur. I will, and often do, underexpose at ISO 3200 rather than go below 1/400.
gbee wrote:
Any chance you'd stay on topic ~~ the 70~200L ƒ2.8 zoom and the convertor.
I have great shots from the 300mm ƒ2.8 and convector too. Not from the combo under discussion.
Well the question was about the 1.4 converter... If you're going to notice a drop in quality from any lens it would be one which pushes it really hard from the start.
I did refer to the 70-200/2.8 because I have my own example but unfortunately I'm moving house at the moment at can't find the pics I was looking for.
Nill Toulme wrote:
At least a part of your problem there could be motion blur. Over the years and hundreds of thousands of frames, I've found 1/400 to be the absolute minimum for consistently getting reasonably sharp images shooting action sports. 1/320 and below and I start losing an unacceptable number to subject motion blur. I will, and often do, underexpose at ISO 3200 rather than go below 1/400.
Nill
~~
www.toulme.net
Yeah i figured it was that. I know i can't expect to get everything bang on in those sort of conditions. I just found the 1.4x to degrade the quality somewhat.
The main problem was the awful lights tbh. In good weather the 1.4x is pretty good.
I think a faster lens is key for me. Even a 300F2.8 would have given me an extra stop which would have been a big difference in the outcome i think. Ugh, time to start raiding the piggy bank or to start ebaying the less used organs!
The Kenko 1.4X Pro 300 did better than I expected on a 70-200IS (this was shooting Div 1 college football on a sunny afternoon).It was much better stopped down stop or so.So lower light might be difficult.Focus was fast and accurate.
J.D. wrote:
Well the question was about the 1.4 converter... If you're going to notice a drop in quality from any lens it would be one which pushes it really hard from the start.
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If by that you mean to say that the drop in IQ should be more apparent using the 1.4x on the 300 f/2.8 than on the 70-200, then that's incorrect. As I recall, the Canon TC's were actually designed in conjunction with, and specifically for use on, the big white primes. There's precious little IQ degradation with the 1.4x on any of those lenses, and the 2x is also very good on them.
Using them on the L zooms, in contrast, is a relatively severe compromise, and the effect on both IQ and AF performance reflects that fact.
That's interesting. I would have thought that, being such high performance lenses, any drop in IQ would have been more noticable but that is based on my (incorrect) assumption. I think I have the MTF charts for this so I'll have a look.
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