I was able to get out and do some initial testing of of the RF 2x converter with the Canon R5 and Canon 100-500L lens.
Aviation (jets no prop planes at the Air Force base)
I went out to Luke Air Force base here in Arizona to see how a 600-1000mm f/11-f/14 lens would do on some jets. I'm not on base when I shoot here, but you can get really close, especially to the landing patterns and this range was actually a bit too much. However, I was pleasantly surprised at the results. The details are sharp and clear. The obvious issue is shooting at f/11-f/14. Even in the bright Phoenix AZ sun I was shooting at an average of 1600 ISO and up to 3200 ISO if some clouds decided to sneak in for a bit. And I was shooting at around 1/1600th of a second, which is about as slow as I like to go on jets if I can help it.
With this range I needed to start thinking about heat and haze as well. If the subject wasn't close enough to fill most of the frame then the image was a bit soft, they were useable sure, but without the 2x converter and the bare lens I would just need to wait a bit for them to get closer and I could get a much cleaner shot. This isn't anything new though, and certainly not something unique to this setup, as most extremely long focal ranges can suffer from this. You need to know your conditions.
One thing I wanted to try more was shooting the jets as they taxied out to the runway. In these situations you can slow the shutter down, lower the ISO and get some cleaner shots. However, being a very sunny day, heat distortion was an issue. Of the shots I was able to get, there was very little cropping needed which is something I could never say before!
Here are a couple shots from the afternoon;
1000mm, f/16, 1/1600th, ISO 2500
600mm, f/11. 1/1600th, ISO 1000
1000mm, f/14, 1/1600th, ISO 1600
This is an uncropped image of an F35 coming in for landing while using the lens at 1000mm. Being this close was a challenge to keep it properly framed!
1000mm, f/14, 1/1600th, ISO 3200
Uncropped image of an F16D coming for landing at 600mm
600mm, f/11, 1/1600th, ISO 1000
1000mm, f/14, 1/1600th, ISO 2000
1000mm, f/14, 1/1000th, ISO 1250
Birds
This weekend I went out to a local wetland preserve to see how the 2x converter faired with shooting some birds. Normally when I head to this location I'm shooting egrets, herons, the occasional raptor, etc. However it was extremely slow and birds were pretty scarce to I needed to find some small birds instead and at this point I held little hope this was going to work well as small birds are a pain as it is, adding an f/14 lens into things isn't going to make it any easier! Well, again I was pretty surprised.
As great as 1000mm is, with the f/14 aperture to get any decent separation from the background you either need to get as close as possible, or have your subject far away from anything behind it. And these cormorants where on a small island with nothing behind them for at least 100-200 feet.
944mm, f/14, 1/800th ISO 800
1000mm, f/14, 1/800th, ISO 800
I was not only surprised at the detail, but also how useable 1000mm could be for some of these small birds
1000mm, f/14, 1/800th, ISO 800
1000mm , f/14, 1/800th, ISO 1600
1000mm, f/14, 1/800th, ISO 2500
856mm, f/13, 1/800th, ISO 1250
And for fun, a 1:1 (or close to it) crop of a hummingbird taken at 1000mm
1000mm, f/14, 1/800th, ISO 800
Conclusions
Would I use this combination again for jets in flight? No, I don't think so. I think the 1.4x converter would do a better job of retaining detail and keeping settings in a more optimal range, and I can always crop in a bit if needed.
Would I use it for jets on the ground? Yes, definitely. I think on the right day, cooler with some cloud cover, this would be great to get some long-reach shots of the jets taxiing out and doing the initial take-off as you can keep the shutter speed much lower
What about birds? That's a tough one, but I thing the 1.4x converter is better suited here as well. Sure the 2x converter is useable here in Phoenix, but if you lose any light then expect the ISO to shoot up very quickly, and there's little latitude with other settings as you usually need a decent shutter speed for moving birds. This may work well for larger wading birds like herons and egrets though.
In the end I think the RF 100-500L lens is better paired with the 1.4x converter. That combination shows almost no loss of overall image quality or AF speed and accuracy. The 2x will be much better suited to the larger, faster RF prime lenses coming out and I think that combination is going to be simply amazing for those that can afford it!
The 2x converter will travel with me in my bag and come out in the occasion where it can be used. I was extremely happy using it for butterfly shots a week ago, so much that it may be something I use over my 100mm f/2.8L IS macro lens because I have no worries of scaring the butterfly/insect away.
I don't think anyone would be disappointed with the performance of the RF 2x converter as long as you understand the limitations it brings with it.
