500mm: Extender or Crop Camera for Reach?

Recently purchased a 500mm f4 and am wanting more reach to photograph eagle's nests and other stuff that is too far away. I have a 1DX and a 1.4x II now and am debating on getting a 2x III or maybe a crop camera like a 7D since they're relatively cheap now but don't know what to do. I've had the 7D before but wasn't a big fan of the noise in the photos but it would get sharper images than the 2x I would think. Any opinions? Thanks.

Your 1DX has 144 pixels/mm. If you do not purchase an APS-C with a HIGHER number of pixels/mm, you might as well simply shoot with the 1DX and crop during postprocessing.
Fortunately EVERY Canon APS-C dSLR ever produced has 155 pixels/mm and more, all the way to the 80D with 266 pixels/mm!

The results with teleconvertor are lens dependent. Photozone.de used to test Canon 70-200mm zooms of all sorts with and without Canon teleconvertor; with the 1.4x Canon the 70-200 typically dropped about -10% in performance; I would guess that, at best, you can expect a -20% drop from a 2x teleconvertor.

In this reach for 'reach', folks need to keep in mind that shooting with APS-C is merely 'like magnifying by 1.6x more', and the lens' performance degrades in the process, too. A lens which could deliver 120 line-pair/mm to the film or sensor results in 6.7 line pairs/millimeter on a 16x24" enlargment from FF, while it delivers 4.4 line-pairs/millimeter from the APS-C image, due to 1.6x more enlargement to produce the 16" tall print from 15mm vs. from 24mm

So one might deduce that there is often some 'unused' lens resolution that more pixels/mm can tap into. And by tapping into that, one might somewhat offset the loss of lens resolution due to higher magnification due to format size. It would seem that 218 pixel/mm might be the crossover point needed in APS-C (vs. the 1DX) ...35% better sensor resolution to offset the 35% loss of detail due to greater enlargement to final print size. The 7D has 232 pixes/mm.

aviator.4.life wrote in post #18222638
Recently purchased a 500mm f4 and am wanting more reach to photograph eagle's nests and other stuff that is too far away. I have a 1DX and a 1.4x II now and am debating on getting a 2x III or maybe a crop camera like a 7D since they're relatively cheap now but don't know what to do. I've had the 7D before but wasn't a big fan of the noise in the photos but it would get sharper images than the 2x I would think. Any opinions? Thanks.

Hi,....I have the same lens. I get great results with a 2 x TC (III). I mostly use a Canon 1d4 with a 1.4x TC (III).
I have tried the 7d(2) body but to be honest I much prefer the 1d4 and so the 7d(2) went back to the shop. There are so many posts in this forum comparing the 2 camera bodies. Don't get me wrong they are both great bodies but the 1d4 just felt right.

I suggest you check out the images in the thread .....

"Canon EF 500mm f/4L IS USM" it may help you decide on what to go for.

Just my opinion: If your 500 is good enough to resolve the 1Dx sensor with 2x teleconverter, then get the 2x.

My reasoning below.

Like Wilt said, before "upgrading" to a sensor with more pixel density, you need to understand if your 500/4 (which version ?) + 1.4x is able to resolve that resolution. This is the precondition.
Then, you need to understand how much would you gain in magnification switching to the 7D but still keeping the 1.4x teleconverter on. This is easily done by checking the pixel pitch of the old and new sensors:
- 1Dx = 6.91 µm
- 7D = 4.29 µm
And the linear resolution gain with the 7D would be 1.61x.
The downside is that the pixel area of the 1Dx is 2.6 times larger and the sensor technology newer, so I would expect about 2 stops worse noise performance on the 7D.

Instead, just keeping the 1Dx and switching from a 1.4x to 2x will give you an extra magnification of 1.41x, though at the cost of 1 extra stop of light, therefore 1 stop worse noise performance than with the original combo. Of course, the precondition on optics resolution would still need to be checked on the 1Dx sensor.

To sum it up, moving your 500/4 from 1Dx+1.4x teleconverter to:
- 1Dx+2x: you'd get 1.41x extra magnification, 1 stop worse noise performance, keep the superior body
- 7D+1.4x: you'd get 1.61x extra magnification, about 2 stops worse noise performance, downgrade to inferior body

Now, pick your poison

Appreciate the fast replies, I'll just get the 2x. Won't be as sharp but with some PP I can manage it.

aviator.4.life wrote in post #18222738
Appreciate the fast replies, I'll just get the 2x. Won't be as sharp but with some PP I can manage it.

I never use a TC for sharpness; I use a TC for better sampling of the lens (and therefore the subject), when most of the frame would otherwise be wasted on crop-away non-subject-matter. A TC is always at least a tiny bit less "sharp" than the bare lens at the pixel level, and that is not in the least bit counterproductive to why I use it. Sharp pixels mean that your lens' potential detail is being wasted on huge pixels.

1.4 TC and/or 5ds

ed rader wrote in post #18222801
1.4 TC and/or 5ds

That's not in the OP's options.
With "money ? what's that ?" assumption, the way to go would be 5DS and 600/4 II

CheshireCat wrote in post #18222859
That's not in the OP's options.
With "money ? what's that ?" assumption, the way to go would be 5DS and 600/4 II

Actually my £/$ no problems answer to my long range needs would be the 5DS coupled to the 1200mm, and a Scarff Ring mount for my wheelchair! With a second 5DS with the 600mm mounted alongside, the Scarff ring could manage a twin Lewis Gun setup, so I would expect to manage a twin camera installation, even with the 1200 and 600mm lenses. For anyone wondering what I am talking about, this is a Scarff Ring mounting twin Lewis guns on a 1918 vintage Bristol F2b Fighter.

Photo from BigAl007's gallery.
Image hosted by forum (754315)

I only shoot the 500/2X from a tripod, I've been happy with the results.

I have done only one test like this, and it wasn't the same equipment, but it might be relevant. I have a 100-400 II, a 5D III, a 7D (first generation), and a 1.4 x II.
compared the 7D with the 100-400 @ 400 mm to the 7D with the 100-400 @ 350 mm and the 1.4 x, which gives the same framing. In retrospect, I should have adjusted this a bit to compensate for the small difference in pixel count, but the results were so clear that it wasn't worth redoing it. I shot a high-resolution chart and examined the results at 100%. The results using the 7D without the 1.4 x were markedly better than the results with the 5D III and the 1.4 x. The image with the teleconverter was not as sharp and had noticeable chromatic aberrations. Of course, the difference would be much less apparent in real life, when not pixel peeping, but they were big enough that I decided to stick with the 7D when I need reach and have a choice.

Of course, I would expect the 1.4 x III to give better results, but I don't have one to try.

paddler4 wrote in post #18226404
Of course, I would expect the 1.4 x III to give better results, but I don't have one to try.

And I would also expect a 500/4 to give better results than the 100-400 v2.
Both v3 teleconverters are certainly not a problem for the 400/2.8 v2.
You may also have a defective teleconverter.
Can you post your results ?

aviator.4.life wrote in post #18222638
I . . . am debating on getting a 2x III or maybe a crop camera like a 7D since they're relatively cheap now but don't know what to do. I've had the 7D before but wasn't a big fan of the noise in the photos but it would get sharper images than the 2x I would think. Any opinions?

If I were in your shoes I would get a 7D Mark 2, not the original 7D.

I have a 2x version 2 and a 2x version 3, and there is no difference in sharpness - net even when pixel peeping. I think that any difference is only appreciable when using the version 3 tele-extender on one of Canon's new version 2 supertelephotos. Is your 500mm f4 I.S. a version 1 or a version 2?

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