Canon 300mm F2.8 L IS (Mark I) with 1.4TC vs Canon 400 F5.6 L

Az_GTi

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Afternoon boys and girls. Not often I posted in this section - if ever! I'm usually out and about snapping!

Would really appreciate your thoughts on this though, especially if you have owned both these lenses!

I have a 400 5.6. Love it, great bit of kit. Even made a little review of it here - http://www.ae-photography.co.uk/canon-400mm-f5.6-lens-review.html

Anyway I'm toying with idea of selling my 120-300 and getting a Canon 300 2.8. The Mark II is too pricey but the Mark 1 I can probably just stretch to.

I know without TC the lens is a corker. But 300mm can sometimes be a bit short. However with a Canon 1.4 TC (II) would you say IQ and AF speed is better or at least as good as the 400 5.6?

I've seen a few thread here and there and some comparisons but nothing really real life. So wondered if a few of you could chip in.

cheers
Az
 
I don't perceive IQ as an issue (with or without an TC) but the AF speed isn't as good as the 400/5.6 even without a TC (which reduces the AF speed to 50%). The 400/5.6 has a long MFD giving it the advantage of a very short focus throw and is very quick as a consequence..

Bob
 
This is marginally off topic as it refers to series 2 lenses and series 3 extenders, but is taken from a Canon US learning centre article.
I must say, I see no appreciable drop in AF speed with my 300 2.8 mk2 and 1.4 extender, and not a lot with the 2x either, Bob.

Interested to see your comments.

I quote...

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  • Glossary

    Three extra data contacts on lens mount for compatible EF lenses
    If you look at the rear mount of a Canon EF lens that’s officially compatible with EF Extenders, you’ll see that it has three additional gold plated electronic contacts on its lens mount. But these are not present on lenses that are not extender-compatible. The extra contacts on the lens match with three additional contacts on the front mount of an EF 1.4x or 2x Extender, allowing a microcomputer in the extender to perform the following:
    • Convert lens focal length information being conveyed to the camera
      This is done so that shutter speeds in Program AE mode can be shifted to faster settings, which is more appropriate for the effective increase in lens focal length. The converted focal length info is also recorded in a file’s metadata and can be viewed in applications such as Canon’s Digital Photo Professional software. This is the only time you’ll see any impact of this change in focal length information.
    • Converts reported lens aperture information to the camera body
      With the extender in place, information about actual lens f-stops is converted to reflect the 1-stop or 2-stop light loss, in manual or automatic exposure modes. This changes the display seen in the viewfinder or the camera’s LCD information panel. This also has an impact on AF, as we’ll discuss briefly.
    • Reduces AF drive speed, to compensate for reduced focusing movement when extenders are in place
    Change in lens AF speed with EF Extenders
    This last point (directly above) has created sufficient misinformation that it warrants a separate explanation. With a 1.4x Extender attached, the amount of actual focus movement within a lens is reduced by 50%, in order to accommodate changes in actual subject distance. With a 2x Extender attached, the amount of movement of lens elements is reduced by 75%. Because AF systems are essentially computer-controlled to read and react to focus distance changes, the information must be modified so that the focusing movement (or sensitivity) compensates for the added presence of the extender. In the Canon EOS system, this is done by deliberately reducing drive speed when an extender is detected.

    Before you immediately conclude that this is a problem, understand that this reduction in drive speed now corresponds to the effective speed you would achieve with the same EF lens alone. It compensates, automatically, for the reduced distance lens elements in the lens’s focusing group(s) need to move to refocus on a subject, with either EF Extender in place. Accordingly, overall AF performance remains essentially unchanged with an EF Extender attached, versus the lens’s AF speed without an extender.


    The last sentence is interesting!!

    I'll post the link to the whole article below.

    http://www.learn.usa.canon.com/resources/articles/2014/ef_extenders_pt2.shtml

    Not normally up at this unearthly hour, suffering from a cough and cold so hot drinks and Lemsips the order of the day....

    George.
PS...the 400 5.6 doesn't have iS, of course..
 
Coming from a 400mm f5.6 to a 300mm f2.8 and 1.4tc I found no noticeable drop in focus speed.
 
George said:
  • Reduces AF drive speed, to compensate for reduced focusing movement when extenders are in place
Change in lens AF speed with EF Extenders
This last point (directly above) has created sufficient misinformation that it warrants a separate explanation. With a 1.4x Extender attached, the amount of actual focus movement within a lens is reduced by 50%, in order to accommodate changes in actual subject distance. With a 2x Extender attached, the amount of movement of lens elements is reduced by 75%. Because AF systems are essentially computer-controlled to read and react to focus distance changes, the information must be modified so that the focusing movement (or sensitivity) compensates for the added presence of the extender. In the Canon EOS system, this is done by deliberately reducing drive speed when an extender is detected.

Before you immediately conclude that this is a problem, understand that this reduction in drive speed now corresponds to the effective speed you would achieve with the same EF lens alone. It compensates, automatically, for the reduced distance lens elements in the lens’s focusing group(s) need to move to refocus on a subject, with either EF Extender in place. Accordingly, overall AF performance remains essentially unchanged with an EF Extender attached, versus the lens’s AF speed without an extender.


The last sentence is interesting!!

I'll post the link to the whole article below.

http://www.learn.usa.canon.com/resources/articles/2014/ef_extenders_pt2.shtml

George.
Click to expand...

The last sentence is indeed interesting, George.....and the maths behind it have defeated me.

I understand that for the same framing (with and without a converter) the rate of change of focus will be constant for the same subject speed. However, I can't see how this gets derived into 50% for 1.4x focal length and 75% for 2x focal length.
A quick play with the lens and converter clearly demonstrates that drive speed with a 1.4x converter is about half that seen without one so time from MFD to infinity (not really a test of real world) is about double.
If one reads the user manual provided with the extenders .....
"Autofocusing slows down when the lens is used with an extender, in order to maintain the precision of autofocus control"
Another Canon DLC article states
"As with previous EF Extenders, usage of Series III EF Extenders lowers AF drive speed to improve AF performance. When Extender EF 1.4X III is used, AF drive speed is reduced by 50%. When Extender EF 2X III is used, AF drive speed is reduced by 75%. This may seem like a drawback, but in reality subject tracking performance remains quite high when Series III Extenders are used with IS II lenses"

The linked article also states "Tele extenders do not impact or change a lens’ minimum focus distance".
For all practical purposes this may be true but the statement is incorrect. The close focus distance is a property of the lens and remains the same with or without a converter. The MFD is measured from the sensor/film plane and will actually increase by an amount equal to the physical length of the converter body.

Bob
 
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I realise we are a bit off the OP's question, but it is an interesting point, Bob.
Are you saying you notice a drop off in AF on a 300 mk2 and 1.4 mk 3 TC?...I certainly can't measure a difference just using them in real life (which is what really matters)....and the only time i really find the performance suffers (and really only with the 2x extender) is when I try and af using centre and 4 surrounding points with my 400 DO and the x2 which makes it an f8 800mm..and so I really only just that combo for static or nearly static shots.

Been doing a lot of checks with FoCal and my teles and extenders, and, yes, the quality does drop off with them but only marginally, except in the case above with the 400 DO and 2x where there is a more noticeable drop off....but then again, I was in Shetland last year and used that very combo for a couple of stunning otter shots, which I wouldn't have got otherwise.

Going back to Az's original question, I have used both the lenses he mentions, and obviously the 400 5.6 is by far the lightest of the lot, as it's 5.6 and hasn't any IS.

I only borrowed one briefly, but personally didn't like it, I found the af a bit slow (perhaps a problem with the lens as it was a Canon loan one and had possibly been hashed?) and I'd like to throw another lens in to Az'z mix...the 400 DO.

I'm personally a fan of this lens, any lack of contrast can be sorted in pp, and I picked up a used one, 2011 I think so it was also a fairly new one, for £3250ish.

Now here we have a lens which is lighter than the 300 2.8 and with a 1.4 extender will give you 560 f 5.6...140mm more than a 300 +1.4!

They can be picked up for around £2500 I think, and I ran FoCal checks for performance on mine before I bought it.
AF performance is I'd say almost as good as the 300 mk1.

George.

EDIT...Az doesn't say which body he's using......perhaps that will affect performance as well, as I presume Bob and I are both talking about performance with a 1Dx.
 
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George said:
I realise we are a bit off the OP's question, but it is an interesting point, Bob.
Are you saying you notice a drop off in AF on a 300 mk2 and 1.4 mk 3 TC?...I certainly can't measure a difference just using them in real life (which is what really matters)....

EDIT...Az doesn't say which body he's using......perhaps that will affect performance as well, as I presume Bob and I are both talking about performance with a 1Dx.
Click to expand...

I'm referring to a 300/2.8 IS MkI paired with a 1.4x MkIII (I don't have a 1.4x MkII). I've also tried with a 2xMkII and 2xMKIII since writing earlier and can't see any differences between the two...they both slow down the AF drive by a comparable amount on a 1Dx.

I've also done a side by side comparison of the 300+1.4x against the 400/5.6 on 1Dx's and Iain's feelings are accurate. Going from MFD to infinity then the 400/5.6 is faster (just) an really only due to it's reduced coverage. If the two lenses are sent to infinity from 3.5m (the first common marked distance that both lenses can achieve) then they're as near identical as makes no difference.

Bob
 
Unfortunately I can't do any checks at the mo as my only body (I'm waiting on the new, I hope, 7D) and my 1 Dx is off to Elstree for a quick check,but I think that the mk2 lens is better with mk3 extenders than the mk1 with mk2 extenders, I changed when I upgraded.

I don't currently have a 400 5.6, so can't comment on that.

From the checks I did before I upgraded the lens, the mk3 extenders were not any advantage over the mk 2 extenders with a mk 1 lens.

When I used a 200-400 f4 +1.4 recently for about a month, again the extender, when flipped in, didn't noticeably seem to affect AF.

When I get the gear back, later next week as it's just awaiting collection, I'll check, perhaps you'd let me know exactly how you did the tests in terms of settings (af point selection etc).

George.
 
Some interesting comments and info, thanks for taking the time to post/share.

I'm intending to use the lens on a crop body, either a 7D or 70D - both I have. I also have a 1D3 which I will use with my 70-200 2.8 II lens.

I already have a Mark II 1.4 TC and to be honest I don't think that much of it. It works ok on my 70-200 but I can feel a difference (reduction) in AF speed and see a very slight softening of the image (expected). Maybe the Mark III extender does improve things. I'm hoping that with a prime the effect of a TC won't be as noticeable. I'm getting my hands on a 300 2.8 I lens this weekend so I will be able to do a proper "real life" test and see how it performs. If it performs well with my 1.4TC (hopefully as good as my 400) then I will probably sell my 400 5.6 too (even though I really like it). That's the plan anyway, will see how it goes.

George the other reason for going with a 300 is "sometimes" for me 400 is too long. Also 2.8 is really handy for isolating from background and in low light etc, so I don't think the 400 DO is for me but thanks for highlighting it.
 
Be interested to hear how you get on, I don't think a mk 3 t/c would be any better than a mk2 on the 300 2.8 mk1, but I'm a little surprised you are getting a noticeable (although slight) softening of the image...have you set up MFA and if so did you use Reikan's FoCal?...IMO it's well worth the money as it takes the guesswork out of MFA.

George.
 
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