Canon 70/300 L f/4-5.6 & Kenko Pro 300 1.4X TC Reikan FoCal... Several Questions

[Bill_in_WA]

The time has come, due to some physical limitations, to reduce the weight and size of my backpack kit. While I have a number of smaller lenses I am talking here about my 100/400 and 70/200 IS f/2.8. Want to get the new Canon 70/300 L f/4-5.6 to replace (at least) the 100/400... Hope to find a buyer for it. Will hold onto the 70/200 f/2.8 for the time being although I won't carry it in the field pack.

I have read that the Kenko Pro 300 1.4 TC works well with the 70/300L (Canon TC's don't fit). Because of the pin configuration the AF still works although some have reported that it sometime "hunts" a bit. As I use a 5D MKII for my scenic/water shots and a 7D for my birding and wildlife, the 70/300 appears to be a happy medium (480mm on 7D... 672mm w/ 1.4 TC) as it is both lighter and smaller. The IQ and IS of the lens appears to be very good and I will be happy to do away with the "pushme / pullyou" FL adjustment of the 100/400... never have gotten used to it.

Any thoughts or comments?

Also, is there any reason that I couldn't run the 70/300 - 1.4X combination through the new Reikan FoCal software to accomplish AFMA? or might it not just consider it to be a "straight" 70/300 due to the pin configuration and thus would modify the regular FoCal calibration of the lens ?

Again, thoughts or comments?

Finally, has anyone come up with an alternative to the "out of control" $180 price of the 70/300 tripod ring/collar... Canon didn't do us any favor on that one! Have heard of some "store-front" alternatives that turn out (for the most part) to be very sub-standard and vary in construction from "passable/good/metal " to (unusable/plastic).... trouble is you never know what you're going to get... even from the same "store"... I know, you pay for what you get!!! In this case I think Canon is just a wee bit "over the top".

Thanks for any input

Bill

[ChadS]

I'll trade ya a 70-200 f/4 IS for your 70-200 IS f/2.8 - that'll save you some weight... !

I don't think the hunting has anything to do with AFMA. That's just a consequence of using an extender on a lens as I understand it. Some work better than others. The Gen 3 apparently work really well with the new super telephotos (and the 70-200 IS f/2.8 II) but not so well with older lenses - both in terms of IQ and AF speed. This makes sense as the camera is expecting a certain profile from the lens and not getting it - not to mention isn't got a slower f/# to focus on (the faster the f/# the more you can tell you're drifting out of focus).

[Bill_in_WA]

ChadS
Thanks, I suspected that what you indicate was the case... just wanted to make sure. Appreciate your offer but think I will keep the 70/200 IS f/2.8 for the time being... Don't really know why but it seems to make sense (uh-oh).

The "hunting" is not all that common, just enough reports to get your attention... With good light/contrast the AF seems to work fine with the Kenko unit.

The 100/400 is the one lens that I would like to find a home for... The major on-line stores are only offering about half in trade of what they are selling the used units for... I would hit a happy medium... Doesn't really take good pictures sitting on the shelf at home!

Thanks for the input
Bill

[Dr Croubie]

good timing, I just got my Kenko Pro300 DG teleconverter a week ago, specifically for my 70-300L on 7D.

I was planning to do a good review of this combo, but it's crap weather and I haven't had time, so here's the main points:
Firstly Kenko has 3 types, MC4, MC7, and Pro300. Older ones are marked 'DG', newer ones are 'DGX'. I'm not sure if that makes 6 permutations or less, doesn't matter. I'm speaking for the Pro300DG because that's what i've got.

On the instruction manual/sheet I got, it specifically says that 10-pin lenses (like 100-400L and the tele-primes), the aperture gets translated. For 7-pin lenses, the teleconverter is 'invisible'.

What that means is:
- your EXIF-data will show 70mm to 300mm, f/4 to f/5.6, even though you're in the range of 98mm to 420mm, f/5.6 to f/8.
- the camera thinks a max 300mm f/5.6 lens is attached, so it will try to AF, all the time. (if you attach, say, the 100-400 to a non-1-series, the camera will see that the aperture is f/8 and not even try to AF).
- But, it's very hit-and-miss with actually locking on. So far I haven't tried it in really good sunlight, but at 70mm (98mm f/5.6), it's not so bad, and can lock on easily enough (outised just then, in cloud). The longer you get, up to 300mm (420mm f/8), the worse it gets. I'm having a lot of trouble locking onto anything at 300mm (420mm), but then I haven't tried a proper test-target, nor in good sunlight. Sometimes it does nail it though, but it's going to take a lot of practise, i've been on AI servo so far, i'm going to try one-shot and Full-Time-Manual to fix it if it misses.
- Because the converter is 'invisible', the AFMA you set for the basic lens is the same as with the teleconverter. With the teleconverter attached, the camera still thinks I have a plain 70-300L attached, so when I've taken a photo, the EXIF still says it's used the same +2afma-value as I've set for the plain lens.
- I've tried using it with manual-focus primes (with no chip), and if i try take a photo, the camera gives an 'error 99' and says the contacts are dirty. An MF lens with an AF-chip on the adapter works fine though.

- But i'm still happy with it. I already had my 70-300L when i bought the t/c, so for $60 (ebay) I couldn't do any better. For the next-cheapest options for longer-lenses with AF, there's the 400 f/5.6, the 100-400 f/5.6, 200 f/2.8 and 2x t/c, or a 1-series body (and then I lose the 7D's 1.6x crop), all of which cost well over $1000 and then some. Even if I can only ever use it in MF, that's still cheaper and much better IQ than an older manual-focus 400mm lens, plus i get the great build-quality and IS of the 70-300L.

- But if you don't own it already, think about how much you need to get to 420mm. If you want to be there all the time, keep the 100-400L, the shot you take with AF will be better than the shot you miss with the 70-300L+tc hunting (not sure about IQ comparisons, although i'm guessing the 100-400L will be better anyway, natives generally always beat shorter+tc). Other than that, the 400 f/5.6 prime is cheap without IS, the 70-200 f/2.8L non-IS with a 2x t/c gives (i've heard), not as good IQ as the 100-400, but it's more versatile and faster on the wide end.

Meanwhile, the sun just came out, i'm going to see what it does in brighter conditions before the clouds come back...

[Dr Croubie]

Damn, 1 minutes later and it's raining again.

Did get a quick try with One Shot AF, but didn't work. The lens didn't lock anything, even FTMing it back to focus it, the shutter wouldn't fire because the camera didn't think it was in focus.
And once on AI Focus, I kept pushing it back to in focus, but the camera just pushed the lens back to infinity-focus (OOF) and kept it there and wouldn't fire the shutter.

There's a custom-function to turn off focus-hunting, i'll try that next time it's dry outside. But for a 'real' answer on how well it works, it might take me a few weeks of practise...

[Dave Throgmartin]

I rented a 70-300L with a 1.4 Sigma converter and impression was the 300mm length + cropping was a better result than the Sigma converter, but I didn't have the set up that long.

Dave

[Dave Throgmartin]

Here are my real world shots I wrote about before.

With TC




























Without TC



























With TC cropped







































Without TC cropped

































I think that in this case the picture without the TC is clearly sharper when cropped. This was using a 1.4x Sigma. Maybe the Kenko will deliver better performance?

Dave

[Bill_in_WA]

Dave,

I agree, the TC crop is better. It remains a little softer than I would have expected... How far away was the eagle and what camera again?

I would be amazed if that shot wasn't taken near Edison, WA in the Skagit Valley... If not we have proven that there are at least two absolutely identical areas (and trees) around the country.

Regarding the TC's... I think, with the 7D I would have good reach... If I needed to use a TC I would simply revert to something they call Manual Focus... It seems as though the AF problems amplify the higher FL that one tries to use so why not just pack it in to start with.

As I first indicated, this whole thing is brought about by some physical limitations that have created the need to "lighten the load" in my pack... every few ounces count. As I have re-thought the situation (for about the hundreth time) I am now of the opinion that my "boonie's" or "travel" pack would consist of the 5D MKII w/ 24/105 and/or the 7D w/70/300 and a 17/55 f/2.8 EF-S (in case I do a "swan dive" with the 5D). That would give me pretty good FL, quality, and back-up.

I am truly impressed with what I have read and heard about the 70/300L.

As for the 100/400 IS (brick) and the 70/200 IS f/2.8 (bigger brick) I am now thinking about keeping them for "local" use or where I know that is the only lens I will need for the intent of the shoot. In that either of them will only bring just over $700 in trade it isn't worth getting rid of them.

Won't even go into the 50 f/1.4 and 100 IS f/2.8 Macro.

I am nothing if not indecisive!!!

I guess, in a few years, I can always use them as "pins" when all that is left for me to do is lawn bowl!!!

Thanks for the help.

Bill

[Dave Throgmartin]

Bill,

It could have been the autofocus. I took this hand held, but if I had some time to work with and a tripod maybe I could have manually focused to get better results. The other difference could be Sigma vs Kenko. Like you said the Kenko is highly regarded.

The picture was taken at Rock Cut State Park in northern Illinois just before Halloween using a 60D and center point focus. Camera settings were f/5.6, 1/2000 second, and ISO 320. The eagle was a long ways away! He was all the way across the lake. The above pictures show the original at 300mm and 420mm focus distances. The eagle itself in the non-TC shot is only 147 x 284 pixels.

I think the overall quality would be better if the branch hadn't been in front of his face. If the bird's eye isn't clear, or visible at all in this case, it really hurts the image. I actually thought the feathers look ok.

Dave

[Bill_in_WA]

Dave,


Haven't done much in the way of attachments on the forum but will give it a try... The two shots in the trees were taken with 100/400 with 1.4X Canon TC at about 700 mm equvalient on a 7D. Took a while in the two eagle shot to get them looking different directions. On a full crop it could have been better.

Will just have to keep trying... There is a BIG influx of Snowy Owls out here this year... lots of them over on the coast near Ocean Shores hope to get out before they hear North.

I think I have miossed the B&H special on the 70/300L, Haven't looked yet but I believe it went off last night... figures!