2x teleconverter? (Page 4): :sm24: :sm24:...

imagemeister Loc: mid east Florida

Gene51 wrote:

I think what you are seeing is the incredible sharpness of the 300mm F2.8 L. It is so sharp that even with a 25% loss in sharpness, it is still as good than many cheaper lenses without using a TC.

CHG_CANON Loc: the Windy City

mas24 wrote:

After viewing your Canon 2XII Extender, I was curi... (show quote)

mas24 - I pulled the vII image from a used for-sale listing at Adorama. Gene51 provided a random statistic he's used before about a 25% loss of quality. I've posted an real-life example as have others, some even with the OP's lens. I don't remember anyone posting examples involving 3rd party equipment, neither in support nor to disprove a 25% loss in image quality. None of the contributions to the discussion that reference 3rd party products seem to be in support of the idea.

odonnellake

Thanks! That does help!

bwana Loc: Bergen, Alberta, Canada

odonnellake wrote:

I am strictly a hobbyist and am looking for an aff... (show quote)

You give up speed, i.e.: require lower exposure or higher ISO or larger aperture, image quality and possibly the ability to autofocus. A 2x teleconverter will magnify the imperfections in any lens you use it with by 2x. If you must go with a teleconverter, I'd recommend a 1.4x unit.

bwa

Notorious T.O.D. Loc: Harrisburg, North Carolina

The problem the 1.4 is that it doesn't gain you that much with a 70-200 lens or with a prime less than 300mm in my view. You might just be better off with a crop body and the reduced FOV. Or get the best quality 2.0 that is made to work with the lenses you plan to use. That is what I did. I just didn't see going from 200 to 280 as worth the cost on a full frame camera. I can gain just about as much with the 1.3 APS-H sonsor on my 1D MkIII. Your mileage may vary. I still wonder if some of the loss in image quality can be countered with the RRS long lens support. I need to figure a way to test that I guess...

Best,
Todd Ferguson

bwana wrote:

You give up speed, i.e.: require lower exposure or higher ISO or larger aperture, image quality and possibly the ability to autofocus. A 2x teleconverter will magnify the imperfections in any lens you use it with by 2x. If you must go with a teleconverter, I'd recommend a 1.4x unit.

bwa

taco40

From what I'm told, you and I both already have a built-in teleconverter of sorts. The 60D (I have a 70D) has what is called a cropped sensor. Because it's a smaller sensor, it appears to have the same effect of a 1.5x teleconverter. The pixels are compressed so the image quality isn't as awesome as a full sensor like a 6D or 7D. I've gone into a few camera shops asking about teleconverters and I've been counseled against it every time over the last decade. With a 400mm focal point, my lens, in effect acts like a 600mm.
It appears that both of the following sites assume you are using either a cropped sensor camera OR a full sensor with extendor...

link:https://petapixel.com/2016/11/14/teleconverter-vs-crop-sensor-teleconverter-bad-decision/

and: https://www.diyphotography.net/shooting-wildlife-crop-sensor-vs-full-frame-1-4x-teleconverter/

imagemeister Loc: mid east Florida

Notorious T.O.D. wrote:

I still wonder if some of the loss in image quality can be countered with the RRS long lens support. I need to figure a way to test that I guess...

Best,
Todd Ferguson

RRS claims up to 15% increase with the support ....

Notorious T.O.D. Loc: Harrisburg, North Carolina

Yes, which would cut into image quality loss in some way...probably from reduced vibration I would expect. However, I doubt that I am smart enough to know how to test such a claim...

imagemeister wrote:

RRS claims up to 15% increase with the support ....

imagemeister Loc: mid east Florida

CHG_CANON wrote:

mas24 - I pulled the vII image from a used for-sale listing at Adorama. Gene51 provided a random statistic he's used before about a 25% loss of quality. I've posted an real-life example as have others, some even with the OP's lens. I don't remember anyone posting examples involving 3rd party equipment, neither in support nor to disprove a 25% loss in image quality. None of the contributions to the discussion that reference 3rd party products seem to be in support of the idea.

Tri-Color Heron Canon 70-200 2.8 II with Tamron SP 2X one stop down (f8) from bodypod ......on 50d - I think ....

IMO, the biggest concern in using a 3rd party TC with the 70/80-200's may be AF speed .

..

(Download)

Canon 80-200 2.8 L, Tamron SP 2x .....

(Download)

bwana Loc: Bergen, Alberta, Canada

Notorious T.O.D. wrote:

The problem the 1.4 is that it doesn't gain you th... (show quote)

Maybe its just the quality of the teleconverters I've used but I find I can get the equivalent 2x gain simply by enlarging the image in Photoshop or even better in PhotoZoom...

bwa

CHG_CANON Loc: the Windy City

imagemeister wrote:

Tri-Color Heron Canon 70-200 2.8 II with Tamron SP 2X one stop down (f8) from bodypod ......on 50d - I think ....

IMO, the biggest concern in using a 3rd party TC with the 70/80-200's may be AF speed .

..

Both look great to me. Regarding AF speed, I think it's not just a matter of using the extender and the lens, but also the camera body. A professional 1D-series body houses two batteries and a separate DIGIC processor dedicated to the AF system. The 5D and 7D bodies contain the same AF system as the 1D-series, but not the 2nd battery nor the processing power. The rest of the EOS line will likely experience even more of a negative impact on AF responsiveness with an extender installed. So even if the the image-quality impact is negligible, if you can't get the camera to focus as needed, it still might not be the tool for your needs. This is a known issue, even for the Canon version extenders where Canon seems to be working to address for models outside the 1D-series, for example, adding f/8 support to the 80D across the entire AF array.

RWR Loc: La Mesa, CA

CHG_CANON wrote:

mas24 - I pulled the vII image from a used for-sale listing at Adorama. Gene51 provided a random statistic he's used before about a 25% loss of quality. I've posted an real-life example as have others, some even with the OP's lens. I don't remember anyone posting examples involving 3rd party equipment, neither in support nor to disprove a 25% loss in image quality. None of the contributions to the discussion that reference 3rd party products seem to be in support of the idea.

That figure may have came from this report: https://photographylife.com/image-degradation-with-nikon-teleconverters
It has been parroted about as a fact with any 2X teleconverter and any lens, which of course is a crock. If one accepts as true what is said on page 69 of the Leica Compendium, it certainly does not apply to the Apo-Telyt-R 280 or 400 f/2.8 lenses with the APO-Extender-R 2X.

Notorious T.O.D. Loc: Harrisburg, North Carolina

Not going to get the same result by enlarging 2x in my view. Compression is much different at 200 vs 400.

bwana wrote:

Maybe its just the quality of the teleconverters I've used but I find I can get the equivalent 2x gain simply by enlarging the image in Photoshop or even better in PhotoZoom...

bwa

CHG_CANON Loc: the Windy City

Notorious T.O.D. wrote:

Not going to get the same result by enlarging 2x in my view. Compression is much different at 200 vs 400.

Is that accurate? The OP's lens is 200mm. The image comes of the back of the lens and is then magnified by the extender by a factor of 2x. That magnified image is than projected onto the sensor. Does the magnified 200mm image have the same image compression characteristics as an image from a 400mm lens?

Notorious T.O.D. Loc: Harrisburg, North Carolina

From my experience I believe this to be true. The focal length is changed by the Extender, correct? A 400mm focal length is going to have greater compression than a 200mm focal length I believe...

CHG_CANON wrote:

Is that accurate? The OP's lens is 200mm. The image comes of the back of the lens and is then magnified by the extender by a factor of 2x. That magnified image is than projected onto the sensor. Does the magnified 200mm image have the same image compression characteristics as an image from a 400mm lens?