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Author Topic: Canon Extender EF 2x III review - at the bronx zoo  (Read 25038 times)

Ulfius

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Re: Canon Extender EF 2x III review - at the bronx zoo
« Reply #15 on: April 04, 2011, 03:06:36 PM »
Did you try taking identical shots with and without the extender, then cropping down the non-extended shot to the same FOV and comparing?  Also compare the cropped shot after scaling up to the same image size?

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Re: Canon Extender EF 2x III review - at the bronx zoo
« Reply #15 on: April 04, 2011, 03:06:36 PM »

K3nt

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Re: Canon Extender EF 2x III review - at the bronx zoo
« Reply #16 on: April 05, 2011, 04:00:49 AM »
Thanks for the info. I got what I needed.. :)
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branden

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Re: Canon Extender EF 2x III review - at the bronx zoo
« Reply #17 on: April 06, 2011, 02:03:27 PM »
Whoops, thanks kubelik, I agree with you, I misread epsiloneri's post.

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Re: Canon Extender EF 2x III review - at the bronx zoo
« Reply #18 on: June 15, 2011, 11:14:44 AM »
Here is some information about the extender that I viewed today.  It discusses the changes, and explains that you need to mount the extender to the lens before placing it on the camera to get advantage of the improved communications.  We've always been told to do this, and I do, but its interesting to get more info as to why.

http://cpn.canon-europe.com/content/education/technical/latest_ef_lens.do  (go to page 4)

I've pasted it in below.

As a development of Canon's EF Extender Mark II models, the EF1.4x III and EF2x III take the performance of the previous generation of extenders and improve on it in key areas, while tailoring them to suit the requirements of shooting with digital SLR cameras. A new optical design helps to eliminate chromatic aberration, resulting in sharper images that show less colour bleed along high contrast edges.

Digital cameras have slightly different lens requirements to those of film cameras, so the Mark III Extenders employ different lens coatings to help to reduce the flare and ghosting that can be caused by stray light passing through the lens and either refracting off internal elements, or reflecting back off the sensor in the camera.

Both extenders also employ Fluorine coating to help to keep the front and rear elements clean, thereby avoiding dust and dirt on the lens that may degrade image quality with flare.

The handling of the extenders has been modified too – the lens release button is now better placed and easier to use, while being out of the way and less likely to be knocked.

However, the biggest change is within the electronics of the extenders. Both models feature integrated processors to collate and transfer all the information from the lens back to the camera. This includes data about focal length, focus distance and Image Stabilization. The advantage of this is that the camera can adjust settings like AF Microadjustment (if you are using it) to suit the combination of lens and Extender. It also means the AF performance when using extenders is improved compared to the previous generation of extenders when used with earlier generations of Canon telephoto lenses.

To achieve the maximum benefits of this new processor, you need to ensure that you attach the lens to the Extender first, and then attach the whole lens and extender combination to the camera. This way the camera will see a combined "Lens + Extender". If you add the extender to the camera first the camera will recognise it, but will then not be able to deduce that a lens has been added to the front of it.

As with the previous Canon extender models, the lens mounts are dust and drip proof, but in the Mark III Extenders, the lens mount features more screws to provide a stronger and more durable attachment to the camera and lens.


canonwhore

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Re: Canon Extender EF 2x III review - at the bronx zoo
« Reply #19 on: June 15, 2011, 12:01:56 PM »
Figured I'd post a few shots - note photos were scaled down.

http://www.panoramio.com/user/54435/tags/Canon%20Extender%20%20EF%202%20III

hendrik-sg

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Re: Canon Extender EF 2x III review - at the bronx zoo
« Reply #20 on: June 15, 2011, 12:33:05 PM »
I had the oportunity to test the externders 1.4II and 2.0III together with a 50d and 300 2.8 IS. I tried various test shots and used them in the field für birds, almost always on tripod with a normal head, both middle class.

I worried wether the crop camera with the extenders outresolve the lens. i was mostly interested in the center of the frame where my subject usually is.

my conclusion is the following:

- the camera + extende doesnt outresolve the lens, i get more information with the 2.0III than with the 1.4II and more than with the bare lens, if i watch the same framing in the same size with different relative pixel size.

- with the 2.0 i have an equivalent FOV of a 960mm f5.6 lens. Even in daylight i needed best conditions like tripod, no wind, mirror pre actuation, 10s timer or cable release to avoid shaked pictures. with stopping down to f8.0 i got no benefit, maybe because of the quality of the lens/extender combination maybe because of the difficulities mentioned above.

- the 1.4II gives better sharpness when stopped down to f5.6.

- in critical light situations it is better to use the bare lens and crop the image, as with the bare lens i need 8 times less light to take a picture with the same blur relative to pixel size (4 times because of f5.6 instead of 2.8 and 2 times because of the magnified motion). This happens more frequent than i could imagine.

- on pixel level (all pics reviewed at 100%) the 2.0III seams to be as good as the 1.4II but both little worse than the bare lens.

- Focus is slower and hunts somtimes, it needs some practis to track mooving subjects

Fazit: i bought the 2.0III and returned the 1.4II and like a lot to have a good 600mm f5.6 combination which is possible to carry, but it needs short shutter times to get better resolution than the bare lens, at given distance to the subject.



epsiloneri

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Re: Canon Extender EF 2x III review - at the bronx zoo
« Reply #21 on: June 17, 2011, 03:38:44 PM »
To achieve the maximum benefits of this new processor, you need to ensure that you attach the lens to the Extender first, and then attach the whole lens and extender combination to the camera. This way the camera will see a combined "Lens + Extender". If you add the extender to the camera first the camera will recognise it, but will then not be able to deduce that a lens has been added to the front of it.

Strange, I usually attach the TCs to the camera body first, and then to the lens (with power switched off). I've never noticed any problem with the camera not recognising the TC+lens combination. But then I have the mark II TCs, maybe this is a "feature" of the new mark III's.

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Re: Canon Extender EF 2x III review - at the bronx zoo
« Reply #21 on: June 17, 2011, 03:38:44 PM »

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Re: Canon Extender EF 2x III review - at the bronx zoo
« Reply #22 on: June 17, 2011, 07:07:33 PM »
To achieve the maximum benefits of this new processor, you need to ensure that you attach the lens to the Extender first, and then attach the whole lens and extender combination to the camera. This way the camera will see a combined "Lens + Extender". If you add the extender to the camera first the camera will recognise it, but will then not be able to deduce that a lens has been added to the front of it.

Strange, I usually attach the TCs to the camera body first, and then to the lens (with power switched off). I've never noticed any problem with the camera not recognising the TC+lens combination. But then I have the mark II TCs, maybe this is a "feature" of the new mark III's.

As long as you have both of them mounted when you power up the camera, it should not matter.  Many people never turn off their cameras, so the camera would recognize the adapter when it is mounted, but not the lens when it is mounted later.

I think this is the same for all the adapters.

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Re: Canon Extender EF 2x III review - at the bronx zoo
« Reply #22 on: June 17, 2011, 07:07:33 PM »