Kenko 1.4x on my Canon lenses - mixed feelings

Started 3 months ago | Discussions thread
OP AnthonyL Senior Member • Posts: 2,834
Re: Best I can do with Kenko + 100-400

Andy01 wrote:

AnthonyL wrote:

These are some shots from today and I don't think I am going to get much better. The practical problems are:

1) Shutter speed 1/640 + f/8 at widest is giving me higher ISO than my camera is comfortable with.

2) The FL + aperture combination is giving a very narrow DOF

3) The a/f on this "low end" camera is hit and miss.

I suspect a 5D would give better results all round. Anyway here we go:

Though in reality at that range I would not have normally used the teleconverter. Here is one at similar range but different setting without:

You do not need to use f8 when it is just the bare 100-400L ii -All

All bar the last one were with the TC and as I said normally at that range I wouldn't contemplate a TC.  It was just an opportunity to test.  With the TC I have no choice but f/8 or narrower so I lose the full stop.

I generally use the f5.6 on static subjects to increase light. If you have the TC on, then f8 is the best you will get because you lose a stop. It is, unfortunately one of the penalties of a TC, and there is not a lot you can do about it except practice being as steady as possible at slower shutter speeds, and/or accept the IQ penalty of using a higher ISO setting. That is why sometimes cropping may be a better option.

These photos are much better than the first batch you posted.

Well yes, I'm only a few feet away instead of 100's of feet away.

The second photo here is clearly not focused correctly - user error, camera, lens, TC - who knows ? What was the difference between the first, second and third photos, because the second is definitely worse than the others ?

No idea.

Looking back at you first set of photos in the OP, the ones with the 100-400L ii were not terrible, but the 55-250mm one was. This was the basis for my comments - Rebel + kit lens (albeit a decent kit lens) + 3rd party TC + long range bird subject is not a recipe for great IQ.

I've been very happy with most of my 55-250 shots so a bit disappointed not to end up with a cheap 350mm lens combination.

The 100-400L ii, however, is another story altogether - it is about as good a zoom as you will get, irrespective of the body used, and as seen here is more likely to tolerate a TC and produce acceptable results (because the starting IQ is so good).

I'm happy with the 100-400L ii, just was hoping to stretch it a bit and the Canon 1.4x does not a/f with the Rebels.

I am still inclined to think that your camera & 100-400L ii would benefit from a calibration (normally AFMA) which would mean sending both to Canon. Whether that is feasible or not is up to you.

I'll need to do some more controlled tests but I'd rather end up with a camera that I can do it on myself as I can see other lenses with which I'm happy ending up compromised.

The 700D should be a very capable camera - I never owned one as I went from 600D to 70D. But like all Rebels (including the 77D) it lacks AFMA which can be a problem for getting critical focus with some lenses. I do not think it would have a "poor" AF system - is it as good as 80D, 6D ii, 5D iv etc, certainly not, but compared to an old 450D, it should be very capable.

I have only ever used a 5D iv for a short time, never any older 5D models so I cannot comment, but if you are refring to the original 5D, I would think that perhaps it's AF system might not be much more advanced than a 700D, but it should have AFMA, which may help.

With my 600D + original 100-400L handheld. A few years ago.

With my old 70D + 100-400L ii handheld. Best viewed original image and zoomed in.

With my 6D ii and a borrowed original 100-400L with no AFMA


 AnthonyL's gear list:AnthonyL's gear list
Canon EOS 700D Canon EF-S 10-22mm f/3.5-4.5 USM Canon EF-S 55-250mm f/4-5.6 IS Canon EF 40mm f/2.8 STM Canon EF-S 18-55mm f/3.5-5.6 IS STM +5 more
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