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Old Apr 3, 2008, 11:42 AM   #1
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Hello Everyone,

The teleconverter EC-20 claimes a doubeling of the focus of the lense used; does this mean a 150F2 becomes a F300F2? Or the 35-100F2 a 70-200F2? Whoever have the experience with the EC-20, let us know.

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Old Apr 3, 2008, 1:21 PM   #2
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Any teleconverter multiplies the focal length of the lens by the number of times indicated on the teleconverter, at the cost of light by the same multiplier; the image will be darker and the camera (or you if on manual) will have to compensate to get the same exposure.

The EC-14 used with a 150mm appears as a 150x1.4=210mm lens, but you lose 1.4stops of light. The EC-20 used with a 150mm appears as a 150x2=300mm but you lose two stops of light.
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Old Apr 3, 2008, 2:03 PM   #3
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Hi Mike, just curious, is there any perceived reduction in quality of the image from using a teleconverter?
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Old Apr 3, 2008, 4:01 PM   #4
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Mikefellh wrote:
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Any teleconverter multiplies the focal length of the lens by the number of times indicated on the teleconverter, at the cost of light by the same multiplier; the image will be darker and the camera (or you if on manual) will have to compensate to get the same exposure.

The EC-14 used with a 150mm appears as a 150x1.4=210mm lens, but you lose 1.4stops of light. The EC-20 used with a 150mm appears as a 150x2=300mm but you lose two stops of light.
Hello Mike,

Thank you for the reply, does the camara compensate automaticly for the lost stops (if not on Man.)? So, my 150F2 will become with EC-20 a 300F3,5? If so, I buy one straight away! And the AF keeps focusing auto?

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Old Apr 3, 2008, 4:17 PM   #5
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Terpentijn wrote:
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Hello Mike,

Thank you for the reply, does the camara compensate automaticly for the lost stops (if not on Man.)? So, my 150F2 will become with EC-20 a 300F3,5? If so, I buy one straight away! And the AF keeps focusing auto?

Terpentijn.
Yes, it does automatically compensate, but it won't be an f3.5 lens...it willbecome a 300mm f4 lens. The f3.5 setting is an intermediate setting, not a whole stop setting.

Yes, the AF will continue to work.
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Old Apr 4, 2008, 11:07 AM   #6
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Greg Chappell wrote:
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Terpentijn wrote:
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Hello Mike,

Thank you for the reply, does the camara compensate automaticly for the lost stops (if not on Man.)? So, my 150F2 will become with EC-20 a 300F3,5? If so, I buy one straight away! And the AF keeps focusing auto?

Terpentijn.
Yes, it does automatically compensate, but it won't be an f3.5 lens...it willbecome a 300mm f4 lens. The f3.5 setting is an intermediate setting, not a whole stop setting.

Yes, the AF will continue to work.

Fine with me, I do like to shoot in early morning or late evening (twylight?), but F4 is acceptable with IS of E3. Hi ISO and "noise" have not apeared in my E3. Not more than "grain"in hi-speed film. I even think that this noise of the E3 is very much like grain in the old film (Pen F) and ectachrome. In extrteme situations I find horizontal banding, but the conditions are realey extreme, ISO 1600 &EV -2.0 and diafragme full open.

No cam can cope with this, exept very expensive high end equipement and a lot of PP.

Unless I know not enough about my E3 and E1.

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Old Apr 4, 2008, 1:30 PM   #7
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Pickwick wrote:
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Hi Mike, just curious, is there any perceived reduction in quality of the image from using a teleconverter?
There will always be a reduction in quality. If you start out with exceptional optics then results with a 2x TC can still be of acceptable quality. Start out with so-so optics and the results are usually pretty poor.

Also something to consider - I'm not sure of the Oly lenses, bat at least in Canon, TCs will not physically work on many shorter lenses - (TCs in that system designed for use with telephoto and super-telephoto lenses). It has to do with the physical placement of the lens elements - there isn't enough room for the TC element and the rear lens element.

Again, not sure if any shorter Oly lenses are the same way. I wouldn't expect it to be the case with the 3 lenses mentioned. But it's always best to check if you're planning on using it to turn a standard reach lens to a telephoto lens.

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Old Apr 4, 2008, 5:15 PM   #8
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JohnG wrote:
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Also something to consider - I'm not sure of the Oly lenses, bat at least in Canon, TCs will not physically work on many shorter lenses - (TCs in that system designed for use with telephoto and super-telephoto lenses). It has to do with the physical placement of the lens elements - there isn't enough room for the TC element and the rear lens element.
This is not the case with Olympus FourThirds optics, as they are designed with this in mind...there may be issue with Sigma lenses as they were originally designed for Canokon cameras and my protrude.

The only TC issue is with some of the lenses AF doesn't work, and you have to manually focus...there's a list at Wrotniak's site:
http://www.wrotniak.net/photo/43/lenses.html

It's also mentioned in the documentation for your lenses.

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Old Apr 5, 2008, 10:09 AM   #9
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Mikefellh wrote:
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JohnG wrote:
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Also something to consider - I'm not sure of the Oly lenses, bat at least in Canon, TCs will not physically work on many shorter lenses - (TCs in that system designed for use with telephoto and super-telephoto lenses). It has to do with the physical placement of the lens elements - there isn't enough room for the TC element and the rear lens element.
This is not the case with Olympus FourThirds optics, as they are designed with this in mind...there may be issue with Sigma lenses as they were originally designed for Canokon cameras and my protrude.

The only TC issue is with some of the lenses AF doesn't work, and you have to manually focus...there's a list at Wrotniak's site:
http://www.wrotniak.net/photo/43/lenses.html

It's also mentioned in the documentation for your lenses.

You mean there is next to nithing IQ loss?? Not even at Olympus 150F2??

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