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Messages - AlanF

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Canon General / Re: Are Metal Mounts Better Than Plastic?
« on: January 04, 2014, 12:17:47 PM »
In the late 70's Canon switched its FD mount from the old design with a coupling ring to the "standard" bayonet. And they made the first "plastic" lenses e.g. the 35...70mm/3.5-4.5. The magazines were full of discussions why this would be the death of Canon and a shame - while Canon said those "plastics" would be more precise and durable than metal...

My 35...70 (bought in 81) still works perfectly (and my other FDs too!) though I didn't really kept an eye to them while shooting outdoors... A full metal Tokina isn't working for a long time now and my "full metal" german Exakta from the late 60's is working but not smoothly...

And the brakes of some super sport cars are also made of "plastics" - or isn't carbon fibre not a kind of "plastic"???? :) :)

The etymology of "brake" is that it comes from Middle Dutch braeke, related to breken to break. Therefore, this is one example where plastics break!

Lenses / Re: Get a 300mm or 600mm? Oh the agony...
« on: January 03, 2014, 06:56:12 PM »
I am still getting some superb results from my 7D but the focussing with the 300mm f/2.8 II + 2xTCIII can hunt when there is not a contrasty subject. I got sufficiently frustrated yesterday, despite getting some good BIF shots, that in the evening I ordered a 70D and it arrived this morning from WEX. The initial results are looking good, and I'll post a comparison when there is good weather here in a couple of days. DxO tests on its sensor suggest the 70D has significantly better IQ than the 7D.

Software & Accessories / Re: FoCal website not responding
« on: January 03, 2014, 06:46:14 PM »
The licence management came back on again and I quickly calibrated a few lenses. FoCal is the easier than the sloping ruler method!

Software & Accessories / Re: FoCal website not responding
« on: January 03, 2014, 04:42:54 PM »
Thanks Mt!

Software & Accessories / FoCal website not responding
« on: January 03, 2014, 01:58:42 PM »
Order a 70D last night, delivered this morning. My version of FoCal needed updating for the 70D but the management system of the site is not responding. Has anyone else experienced problems with it?

Lenses / Re: Get a 300mm or 600mm? Oh the agony...
« on: January 02, 2014, 04:37:29 PM »
If you are strong and want to sit in a hide (blind) for hours with your gear on a tripod, then go for the 600mm. If you want to walk or hike with a camera at the ready, and also use a hide with a hand held,  go for the 300mm f/2.8 II with a 2xTC III. If you are rich, go for both. It is as simple as that.

Lenses / Re: Quest for the perfect copy?
« on: January 01, 2014, 05:34:19 PM »
I have *terrible* luck with Canon L's....

Some examples with brand new lenses (some issues over multiple copies)...

70-200 II - decentering, broken IS, build quality issues, scratched front element, excessive CA.

35L - USM squealing.

24-70 II - decentered, scratched front element.

16-35 II - USM high pitch squealing.

17-40 - decentering.

I am sure there are more I am forgetting... I almost expect to go through a few to get good a good copy. The 16-35 issue is from yesterday! Waiting for my replacement copy now.

Are you just a lens schlimazel or does it affect your whole life?

EOS Bodies - For Stills / Re: bad senzor on 5D mark III
« on: December 31, 2013, 02:26:25 PM »
Maybe I misunderstood, but I though that the native ISO for this sensor was multiples of 80?

It doesn't matter what the native iso is, the important thing is that the only unmodified iso values that go through from the sensor are multiples of 100, +-1/3ev (125, 160, ...) are digitally modified losing dynamic range - which is nice for movie & jpeg, but if you shoot raw you can do the same thing by over/underexposing 1/3ev.
Here's some more info on this topic:

Thanks for that link.

EOS Bodies - For Stills / Re: 5DMkIII AF performance at f/8
« on: December 31, 2013, 12:35:34 PM »
I was really pleased that you and others persuaded me to use DxO. Like you, I also use PS for final cropping, layers etc. DxO prime works brilliantly on the SX50, which really is iso limited.

EOS Bodies - For Stills / Re: 5DMkIII AF performance at f/8
« on: December 31, 2013, 12:09:25 PM »
The 300 f/2.8 x2 with the 7D does focus slowly, but with the focus limiter it is OK. I got some good birds in flight with it. With the 5DIII, it is very fast.

I have gone over to DxO PRIME for noise reduction and found it miraculous  - it's raised the 7D to new level. Here is a photo I took just over a year ago at 600mm of a kingfisher speeding like a bullet, and I used iso 1600 and 1/4000 s. It has just gone through 1 round of DxO prime with simultaneous USM of 0.9. It's a 100% crop.

EOS Bodies - For Stills / Re: 5DMkIII AF performance at f/8
« on: December 31, 2013, 07:39:17 AM »
You guys wanted real photos, here are some that will bore you rigid - the pixel peepers Nirvana, photos of a brick wall. Not just any brick wall, they are of a medieval chimney seen from my garden. The mortar is lime and grit, the bricks have ancient firing cracks on them. You can check the resolution of lenses by what you can make out of the grit and cracks.

The first collage is of tiny centre 100% crops taken with a 100-400mm L at 400mm and f/5.6, 300 f/2.8 II + 1.4XTC III (420mm at f/4) and a Sigma 400mm apo tele macro at f/5.6. The top row are crops of ~ 400x300 pixels^2 from images on a 7D, the middle row of ~300x200 from a 5DIII, the bottom row is the middle row scaled up by 1.5x1.5 times to give the same number of pixels as the top. All have no sharpening, from RAW images. For these extremes of pixel peeping, the resolution of the lenses on the 7D beats the same lenses on the 5DIII, and the 420 combo beats the Sigma prime, which is marginally better than the zoom.

The bottom collage is of the same chimney, but of different bricks (and more of them but at the same distance) on a different day. The top row is using a  300 f/2.8 II + 2XTC III (600mm at f/5.6) on a 5DIII, with the image on the right multiplied by 1.5x.1.5 times to give the same number of pixels as from the same lens combo on the 7D at the bottom. You can easily see the huge increase in resolution on going from the 400s on the 5DIII in the first collage to the 600 on the 7D in the second.

EOS Bodies - For Stills / Re: 5DMkIII AF performance at f/8
« on: December 30, 2013, 07:04:47 PM »
..... Under it is the same image reduced by 1.6x1.6 times the number of pixels (= 750x594) to mimick what would be the effect of going to FF with the same no. of megapixels on the sensor. .....

You are "mimicking" a negative of the "FF", while not making any allowance for the many other differences.

For a valid comparison I would recommend that you use images for the systems you attempt to compare.

I have many boring images of brick walls comparing 400mm, 420mm and 600mm on my 5DIII and 7D.  The trick of reducing pixel count isolates the factor from the Nyquist theory.  What does '"mimicking" a negative of the "FF"' mean?

Lenses / Re: EF 400mm f/5.6L IS on the Way?
« on: December 30, 2013, 06:42:19 PM »
I've lost patience.... pre-ordered the Tokina 150-600...

I did the same although mine will say Tamron on the side.   ;)
I lost patience as well and bought the 300 2.8 IS II to go with my Mk III extenders.  The IS and IQ rock, but this combo is so much bigger, heavier, and damn, where did all my money go?

how does the 300 f2.8 IS mark I compare to the mark II? The Tamron seems to beat the 300 f2.8 IS with 2x Mk III extender: http://translate.google.ca/translate?hl=en&sl=ja&u=http://www.trinitylumberton.org/category29/&prev=/search%3Fq%3Dhttp://www.trinitylumberton.org/category29/%26newwindow%3D1

The Series II is significantly better. See:

The crop on the trinity website is from the very centre, and I am willing to bet that the Tamron falls off rapidly away from the centre.

EOS Bodies - For Stills / Re: 5DMkIII AF performance at f/8
« on: December 30, 2013, 02:33:49 PM »
Yesterday I was out with the 7D + 300mm f/2.8 + 2xTCIII. It was a beautiful day, with lots of light. Here is a 100% crop (1200x950) of a tree sparrow at 1/3200, f/5.6 and iso 640, processed with DxO prime and 0.5 USM. Under it is the same image reduced by 1.6x1.6 times the number of pixels (= 750x594) to mimick what would be the effect of going to FF with the same no. of megapixels on the sensor. You can see a slight amount of pixellation in the plumage at the back of the neck with the FF when enlarged to 1200x950. The lowest image is mimicking the effect of going to FF but using only 400mm focal length (= 333x264). There is a huge loss of detail on blowing it up.

So, with 400mm as the maximum focal length, you are more limited in what you can take, but you can still take fantastic photos of what is within range. That's why I want to have a 7DII and longer lenses. It may be obvious, but it may be useful seeing the images.

Interesting. Of course this only applies when the lens has a high enough resolving power to satisfy the higher pixel density of a crop body. What I'm thinking of is that given the same pixel count on a crop vs full frame sensor, the full frame will be more forgiving to lens resolving power, because the pixels are spaced further apart. ie a longer focal length lens that resolves less detail still may be good enough to give the same detail as a crop sensor on a higher resolving lens.
I see the effect of resizing on effective resolution

The resizing experiments recapitulate the Nyquist theorem. In order to resolve two points in an image they must be cleanly separated by a pixel on the sensor. More closely packed pixels do require a sharper lens so that the points in the image are not blurred. The sharpness of good Canon lenses with high mtfs is not limiting for resolution, it is their focal lengths that are crucial.

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