March 05, 2015, 05:41:01 PM

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Messages - AlanF

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Canon General / Re: T3 to 7D.....the right thing?
« on: Today at 11:22:47 AM »
I would go 70D over 7D. Similar price point and better noise light etc. on the 70D. not sure about AF performance though...

AF is more reliable on the 70D. Consistency of AF was one of the 7D's weak points, and it doesn't cope with some TC combinations.

Lenses / Re: Canon - Give us 400/5.6L IS NOW!!
« on: Today at 08:33:40 AM »
And f/4.5 is not a sensible choice of aperture.  It won't AF with a  Canon 1.4xTC on many cameras or with a Canon 2xTC on any (apart from liveview).

Lenses / Re: Canon - Give us 400/5.6L IS NOW!!
« on: Today at 04:56:49 AM »
Canon has just done that.  A new lens just as sharp as the old, and they have added a zoom down to 100mm as well. It also closes up small for ease of packing. 

EOS Bodies / Re: 7D Mark II Firmware update??
« on: March 04, 2015, 11:25:34 AM »
Takesomeone1, you are unlucky - my 7DII is just so much better than my former 7D with a very high keeper rate.

You might get less out of it, not more. The Tamron isn't so good with the smaller pixels of crop.

Lenses / Re: Did I get a bad copy of the 100-400mm L IS II?
« on: March 02, 2015, 04:36:13 PM »
Go to
and you will see that there is CA at 100mm but insignificant at longer f.

Nothing unusual about your lens. Go and enjoy it!

The Tamron at 600mm and f/8 on the 5DIII is as sharp at the centre as the 100-400 II at 560mm with a 1.4xTC.
"at the center" is the key word here. Comparing the corners gives a completely different picture:

I would never write "at the center".

Canon General / Re: Spartans, What is your profession?
« on: March 01, 2015, 05:51:21 PM »
University chemist/biochemist, research and admin, author. Lots of travel and always pack a camera.

Canon General / Re: Spartans, What is your profession?
« on: February 28, 2015, 03:35:58 PM »
Spartan? My hero is Odysseus from Ithaca, not those thugs from Sparta. 

Lenses / Re: How to fit your Canon 1.4X Extender to a Tamron 150-600 lens
« on: February 28, 2015, 05:01:53 AM »
From what I've seen and read, this lens is really just a 150-400mm lens. 400 and beyond is soft and the Canon 400mm 5.6 upsized to 600 and even 700mm is sharper at the Tamron's native 600mm setting!  For me personally I'd get the Canon 400mm. And I plan to eventually.

I traded in my Tamron 150-600 and bought a 100-400mm II. The Tamron at 600mm and f/8 on the 5DIII is as sharp at the centre as the 100-400 II at 560mm with a 1.4xTC. It is true that at f/6.3 the Tamron is a bit soft but at f/8 it is very sharp throughout its whole range and supersharp from 300-400mm. If you don't believe me, look at the measurements on the  150-600mm on lenstip, ephotozine and DxOmark, and the centres on TDP. I prefer the 100-400mm II because it is a better size for travel and has lots of nice features. But, the Tamron is still a remarkable lens and the best value for money out there.

Lenses / Re: True reach of 100-400 L II
« on: February 28, 2015, 04:41:56 AM »
If you have a simple lens of focal length 400mm, then it would have to be 428mm from the sensor to focus a subject 6m away. If you have a simple lens a fixed 400mm from the sensor, then it would need a focal length of 375mm to focus an image 6m away. The lens designers do a fantastic job overcoming simple optics, and it is truly amazing to have a lens like the Mk II that has constant exterior length and focuses down to a quoted 980mm, and in practice 900mm, with minimal CA, distortion etc. Well done Canon lens designers!

Lenses / Re: True reach of 100-400 L II
« on: February 27, 2015, 05:48:11 PM »
This is a bit disappointing (especially since I have one on order), but not entirely surprising.

Focal lengths are routinely rounded up (and often times down on wide angles). The 70-300L is noticeably shorter at the long end than the 300L F4 prime. It's quite obvious.

It's disappointing but, I suppose as long as the 100-400 II is 100mm longer than the 70-300L, then that makes it worthwhile.

This is terrible, perhaps I should send mine back. It's clearly dreadful that the lens shortens its focal length as it focusses from infinity down to less than a metre, just to obey the lensmaker's equation and keep the length of the lens constant. You would have thought that the Canon engineers could have the the lens gradually lengthening by about 500 mm as you focussed down to keep the focal length at a constant 400mm. Perhaps the Mk III will do that.

Seriously, in order for the lens to focus down to 0.98 m and have a magnification of 0.31, the focal length drops to 304mm.  It's a small price to pay. 

Lenses / Re: Review: Canon EF 100-400mm f/4.5-5.6L IS II
« on: February 27, 2015, 09:39:26 AM »
There are now many reviews repeating each other, and omitting crucial details. The tests here were done on a 1DsIII only, not a crop. This reviewer, without even testing it on a crop, states that improvement in the corners of the new lens won't be so noticeable on the smaller format. My old 100-400mm was OK on a 5DIII but was soft on a 7D or 70D because a crop sensor with smaller pixels is much more sensitive to the quality of a lens.

You can see from the TDP site that the new and old lens are similar in the centre of a 1DsIII

But, on a 60D, the new 100-400 II is much better than the Mk 1.

THe new lens is much better at shorter focal lengths.

« on: February 27, 2015, 05:26:22 AM »
The OP posted in another thread;area=showposts;u=375238

"What does AFMA mean??? "

People join the forum to learn, so it is great that he has asked. But, it's somewhat tough on B&H when people buy a camera from them and return it because they haven't read the manual.

« on: February 27, 2015, 02:54:57 AM »
He is not saying crop is crap, he is saying that the statement that a 300mm lens is a 480 mm lens on a crop is crap.

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