Sony Crop Sensor vs Full Frame with Teleconverter and Sony 200-600mm
I have a love for photographing the natural world, and of late I have been photographing this using the Sony A7R 4 and a super-telephoto lens. Previously this was the Sigma 150-600mm however, I always felt like a needed a bit more focal length to be able to capture the shots of the birds I wanted to get.
Whilst it would be easy to say just get closer to the birds, the reality is that these are wild animals and for their safety (and often mine) I cant always get as closer as I would like, hence the need for a longer focal length.
The camera I am currently shooting with is the Sony A7R 4, and although I was using the Sigma 150-600mm, I had a plan to get a teleconverter and sadly this is only compatable with the Sony FE 200 – 600mm and some other Sony Lenses, hence, I upgraded to the Sony FE 200-600mm.
I wanted to have a play and look at the quality, and usability of a teleconverter (in my case 2X) with the Sony FE 200 – 600mm, this brings the focal length up to about 1200mm (which is insane) on a full frame sensor. The other cool thing is that the Sony A7R 4 has a crop sensor mode, which reduces the resolution of the image, but increases the effective focal length up to about 1800mm (again also insane).
These are just my thoughts, your milage may vary so as always do your own research and consider your own requirements.
What is a Teleconverter?
A teleconverter can be considered as similar to a magnifying glass, it attaches to your camera as a secondary lens and is mounted between the camera and the actual lens. The effect of the teleconverter is that it enlarges the central part of the lens.
Teleconverters come in a range of magnifications for different cameras, the most common are 1.4x and 2x which increase the focal length by 1.4 times and 2 times respectively.
What are the Downsides of Teleconverters?
There are a number of downsides to the use of Teleconverters, the first is that depending on the quality of the teleconverter the image quality can often be affected. A teleconverter puts a new peice of glass between your camera sensor and your lens, so if the glass is not of sufficient quality then it means the overall image quality is affected.
The second, and more significant downside to a teleconverer is that for every increase in magnification you create, it leads to a decrease in aperture. By applying a 1.4x Teleconverter it means that you lose 1.4 stops of light, and a 2x teleconverter means you lose 2 stops of light / aperture. In the case of the Sony FE 200-600, this means that the minimium aperture changes from f/5.6 to about f/11, and f/6.3 to about f/13 which is fairly significant.
It should also be noted that many camera's also have a minimium aperture required for auto-focus, so by decreasing the amount of light that comes into the camera sensor, you can affect the performance of the auto-focus (or lead to it no longer working).
It is still very early so I am not 100% on my view yet, but I have used the combination of the Sony A7R 4 and the FE 200-600mm with the Sony 2x Teleconverter on a few different sessions which have informed my comments below.
- Using it with fairly still objects (i.e., Birds sitting eating food, pirching et al) seems fairly good, it leads to an incredible increase in focal length.
- Using it with moving objects such as birds in flight significantly affects the auto-focus capabilities making it much harder to nail the shot. I would say my ‘keeper' rate decreased by half (although this could just be because I am new at it).
- The reduction in aperture means that light becomes more important, as a result to keep shutter speeds in the range of 1/2000 (ish) it means that the ISO needs to get bumped up leading to more image in noises.
- Without the Teleconverter, my ISO may have been in the range of 100 – 800(ish), with the teleconverter I am more commonly pushing ISO 1000 – ISO 4000.
- The extra reach is fairly noticable going from 600 to 1200 at full frame, or 900 to 1800 at crop sensor mode.
- Noise can be a significant issue.
All in all I do like the combination of the 2X Teleconverter and the Sony FE 200-600mm with the Sony A7R 4 however, it certainly won't be suitable for me in all situations (like some Birds in Flight) but for stationary birds in good light I can see this being of benefit.
All images have been resized to 2000px on the long edge through Lightroom, also processed with JPEGMini 3.
In this first set of images there was a Rosella eating on the bird feeder so it was relatively still, I had Auto-ISO turned on which pushed the ISO way higher than I would have liked hence lots of noise which could be reduced in post (but I didn't to show you what it looked like). I also kept the dust smudges, really the only editing was to increase the brightness, fix shadows, highlights et al. I was hand holding the camera and lens (although I was sitting down).
In this second set of images, I have two photos of a Black Shouldered Kite. This was a wild animal so I could not get too close, it was a fairly nice day (sun was out) compared to the more overcast day with the Rosella, the Bird was sitting on a partially submerged log and I was hand holding the lens.
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