400mm, with & without 1.4 and 2x extenders (sample images provided)

While surfing thru POTN, I frequently come across posts about using Canon's tele extenders. Since there seems to be a lot of interest and questions concerning the use of extenders, I thought I would share a few images that illustrate the effects they have on the images created with them.

Attached are three images taken with my 50D and the 400mm f2.8 lens.
All 3 images were taken of the same bird, at the same place, at the same time (she was on a nest, and therefore remained stationary for quite a while, allowing me the time to swap extenders).

All images were taken at f8, 1/1000th of a second, and 200 ISO.

The first image is taken with just the 400mm lens, and no extender.

The 2nd image was taken with the Canon 1.4 extender II

The 3rd image was taken with the Canon 2x extender II

Note not only the difference in "reach", that is evident by the amount of the frame filled by the Killdeer - but also note the effect the extenders had on depth of field. The image taken with no extender all shows a significant portion of the habitat elements surrounding the bird in relatively sharp focus. The image taken with the 2x extender pretty much blurs everything out except for the bird itself. The image taken with the 1.4 extender falls in between these extremes. Remember that these images were all taken from exactly the same position, with the same settings.

NOTE: because I can only attach two images to a post, I had to post a "Reply" to the OP in order to show the 3rd image, which is the one taken with the 2x extender.

Note that none of the images have been cropped or edited in any way.
Here's the one with the 2x:

Cool samples Tom.
I have a couple points I'd like to bring up.

"Not edited in any way" unfortunately has little meaning when the image has been reduced in size so dramatically from it's original file size (you did say that they aren't crops)
Going from XXmega-pixels to 700-600 pixels is very heavy editing.

I would consider 100% crops to be closer to "Not edited in any way".

These images clearly show the 2X image being significantly sharper. I fear that means something is amiss. (could be the amount of resizing? could be the original focus? I don't know...)

Change in DOF, .. DOF is effected by aperture, but it is more effected by FL. When you double the FL as with the 2X to 800mm, yes even though you also double your f/stop, that increase in FL will cut your DOF down significantly.

Lastly, for those seeking this kind of example to research a t-con purchase.... Most of you are looking for a t-con to work some kind of magic on your not quite up to the task affordable zoom. (I base this assumption on the evidence of who asks about t-cons most often on this forum) T-Cons can and do work magic, but they do best on multi-$K primes mostly. You can't expect results like the above when you bolt that Kenko 2x to your mid range zoom.

CyberDyneSystems wrote in post #15620836
Cool samples Tom.
I have a couple points I'd like to bring up.

"Not edited in any way" unfortunately has little meaning when the image has been reduced in size so dramatically from it's original file size (you did say that they aren't crops)
Going from XXmega-pixels to 700-600 pixels is very heavy editing.

I would consider 100% crops to be closer to "Not edited in any way".

These images clearly show the 2X image being significantly sharper. I fear that means something is amiss. (could be the amount of resizing? could be the original focus? I don't know...)

Change in DOF, .. DOF is effected by aperture, but it is more effected by FL. When you double the FL as with the 2X to 800mm, yes even though you also double your f/stop, that increase in FL will cur your DOF down significantly.

Lastly, for those wishing to see this sort of post. Most of you are looking for a t-con to work some kind of magic on your not quite up to the task affordable zoom. T-Cons can and do work magic, but they do best on multi-$K primes mostly. You can't expect results like the above when you bolt that Kenko 2x to your mid range zoom.

i mostly agree CDS. but i do think the 70-200L f4 IS and f2.8 IS lense are exceptions with 1.4 TC. nevertheless i rarely ever use a TC because there is no free lunch and i don't own any of the lenses they were designed for.

Yes, some zooms do very well, and the 70-200mm zooms, all of them IMHO are exceptions indeed!
Others are 200-400mm f/4, 300-800mm f/5.6, 120-300mm f/2.8 for example. There are others I am sure.

Tom,
In order to provide direct comparisons, I suggest that you tightly crop about the head of the bird for all shots and post them all, and it will become apparent how detail resolution and image sharpness are affected by the TC. If using LR, first output the largest area crop at its native pixel count, then have the same pixel output from all three crops during Export, in order to size them on the viewer screen identically.

I had intended for the posted photos to be helpful to others who are interested in seeing the effect of tele-extenders on the final images. I did not realize that what I had to share would be subject to so much nit-pickery with regards to semantics.

I will say that I did not edit the photos. All I did was to export the RAWs as jPegs of a size acceptable for posting on this forum. This is not editing. Maybe converting to a jPeg is, at a technical level, a form of "processing", but there were certainly no edits done. No adjustments to exposure, sharpening, saturation, white balance, etc - nothing.


Wilt, I had no intention of using these images as an example of showing sharpness or resolution . . . just wanted to show the difference that extenders had on the framing (with respect to the size of the subject in the frame), and on depth of field.

If anyone thought that this post was about sharpness or image quality degradation, I am sorry . . . but this post was not intended to address those issues. If it was, I would have mentioned these things in my original post. This is also why I did not post any deep crops of the images - why would I do that if I did not wish to address resolution or sharpness?

Thank you Tom! This is exactly the sort of comparison I have been looking for.

Leon

Not to pile on the nit picking, but the effect of the TC would be demonstrated had you shot wide open for each.

f/2.8
f/4
f/5.6

At f/8, you're sweet-spotting all the way across.

FlyingPhotog wrote in post #15621536
Not to pile on the nit picking, but the effect of the TC would be demonstrated had you shot wide open for each.

f/2.8
f/4
f/5.6

At f/8, you're sweet-spotting all the way across.

That was very purposeful. As you say, I sweet-spotted all the way across. That was to have consistency throughout the examples.

I had hoped that some folks would find this post helpful . . . one thankful person, out of 5 or 6 who responded.

Again, I will re-state that the reason for posting these example images was to illustrate the effect that the extenders had on framing and depth of field. The nit-piks all seem to relate to things that were never intended to be a part of this thread (sharpness and resolution).
Did everyone except Dasher miss the point of this thread?

Thanks, Tom. I would be very happy with that 2X shot. Now if I could only afford 400 2.8 to replace my 100-400L.

Thanks for your time and the great comparisions , and wow didnt know the 2x is that sharp.

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Thanks, Think Harder!

Ok, I'll "give in" and show 2 crops so that resolution can be compared. I am attaching, first, a 100% crop of the image taken with no converter. By 100%, I mean that the cropped area is 665 pixels on the long side, and I am posting that at it's full resolution.

The other image is a crop of the image taken with the 2x extender. It covers the same amount of subject area as the first image. Well, almost the same - the bird turned her head slightly so the position is not exactly the same. The version I am posting here is not 100%, because there are simply many more pixels on the same part of the bird's head, and posting this at 100% would be in violation of forum rules. So, I posted it at the same size the other image is - 665 pixels. That way one can compare images that cover not only the same area of the bird's head, but that also cover the same area on one's computer monitor.

I guess the point of me adding these crops is to show a comparison that may help to answer the question, "Is it better to shoot with an extender, or to just shoot without one, then crop".

Of course, the image taken with the 2x extender is "sharer", or better resolved. We have many more pixels on the subject, and pixels are resolution's best friend!

I know there are probably many ways I screwed this up, and I am sure that some will complain about the way I cropped these, or say that I edited the images (other than cropping & resizing) even though I didn't, etc, etc, etc. But this is what I have to offer; simply take it for what it's worth. I hope it helps some to better learn what they can expect from an extender in similar situations with similar gear.

Thanks Tom.

Good stuff Tom. Appreciate the work.