This forum is for questions and general discussion in the field of bird photography and bird photography gear.
Sony Mirrorless For Birding

I decided late last year that Canon had let me down. Canon had not produced a camera suitable for Bird Photography since the long-in-tooth 7D Mark II and other manufacturers had long passed them by. Moreover, a significant portion of Big White lenses must be being sold to such photographers, but apparently Canon was more interested in still cameras being used for video.

Way, way back I started a thread on an AV forum suggesting that still cameras could win the “convergence” race. In those days most camcorders could also take still photos and I feared that camcorders would take away significant market share from the still camera business and ultimately damage the big makers. (I never anticipated the subsequent impact of smartphones on the still and video cameras market.)

I always believed that Canon had read my posts illustrating how a digital still camera could easily incorporate HD video capability and beat out camcorders taking mediocre still images because about a year later, Canon introduced the 5D Mark II which was the first of the DSLRs that could record high-quality video. Movie makers loved it and all subsequent improved models.

Now we still photographers are wallowing in the garbage heap as the big makers wow everyone with the video capabilities of their newest still cameras. We are the forgotten users.

When Canon introduced the R5 mirrorless digital camera, that was the inflection point for me. I have several Canon “L” lenses and was reluctant to change systems because of my lens investment. However, it was obvious that Canon was going to dump their EF lens mount and “focus” on “RF” mount lenses in the future. So if I was to be forced ultimately to change lens systems, then my concern about my current investment in “L” lenses would evaporate. A sunk cost. That is, the release of the R5 mirrorless body Canon made it easier for me to switch systems.

Canon certainly had a video coup with the R5. With a 45 MP sensor it had enough pixels to record 8k video (7680 X 4320 pixels). Sony introduced their high-end new “still” camera about the same time and it didn’t have enough pixels for 8k video. So Canon outfoxed Sony – on the video front. Subsequently Sony has released an 8k-capable “still” camera (Sony a1, a 50 MP body).

So the big camera makers are spending their efforts on video, not still cameras.

But what about still images? Who is leading in this competition?

Think about the Canon 7D Mark II. It sports 20 megapixels per image and has a “lens factor” of 1.6. The lens factor results in improved magnification of telephoto lenses. So a 600mm telephoto becomes effectively a 960mm telephoto lens (600mm X 1.6). That’s what makes the 7D II a better body for Bird Photography in my opinion. Better than the Canon 1D X Mark III.

If the sensor in the Canon 7D II were blown up to be a full-frame sensor, it would be about 51.2 Megapixels. This is an important metric to me. Note that this means that using the Canon R5 in APS-C mode results in fewer effective pixels in an image than one would obtain using the 7D II. Not an improvement, but a downgrade.

When Sony introduced their mirrorless full-frame body, the A7R IV, a couple of years ago, it caught my eye as it had 61 MP. (BSI sensor too – Back Side Illuminated). It also has an APS-C mode which reduces the number of pixels in an image to 26 MP. Note that this is a 30% increase over the 7D II’s 20 MP.

I wanted a better camera for Bird Photography than the 7D II and preferably a mirrorless body. This Sony body costs more than twice that of the 7D II, though. However, again, Canon let me down. They priced their full-frame mirrorless body, the R5, at about $1,000 more than the price of Sony’s A7R IV. So if I wanted to stay with Canon, I would lose megapixels with the APS-C mode. From 20 in the 7D II to less than 18 in the R5. And I would have to pay more. And I expected the new “RF” lenses also to be priced at a premium.

Clearly Canon has let me down. I started with Canon back in the 1970’s when they released their first auto-exposure body. They were innovative in those days, leading the still photography market.

So I purchased the Sony A7R IV body around Christmas. I briefly pondered using an adapter from Sigma (MC11) to put Canon-mount lenses onto the Sony body, but ended up also purchasing a Sony 200mm – 600mm mirrorless zoom lens. I did purchase the Sigma adapter and tried it with my Canon 100mm F2.8 “L” macro lens and it works as advertised, allowing autofocus and autoexposure to function as with a Canon body.

I have taken about 5,000 images since the purchase and am pleased with the Sony. Much better than the Canon 7D II for Bird Photography and the lens is noticeably sharper than the Sigma Sport 150mm – 600mm lens (which is no slouch in sharpness) I was using with the Canon body. Also it focuses more quickly.

The unexpected benefit was with the EVF, Electronic Viewfinder. I set the Sony to auto ISO, whereby I set a shutter speed and select an F-stop and the camera exposes by adjusting the ISO as required. If you use an SLR body and aim at a dark area, the image in the viewfinder also darkens and focus can be difficult, if not impossible. However, with the EVF, the camera adjusts the brightness in accordance with the ISO setting. So when I aim the camera at a dark area, the image in the viewfinder brightens, making it appear like daylight. Recently, for example, I was able to take nice images of a Pacific Wren, a bird that really likes dark locations. The EVF is essentially a video screen with high resolution and a high frame rate.

I had an epiphany then. I realized that I could put on a tele-extender and the viewfinder would not darken, as with an SLR. Although Sony boasted that if I attached their tele-extender, neither focus speed nor sharpness would be adversely affected, I was dubious – but hopeful.

So I sprung for another $700 for Sony’s 1.4X tele-extender. And it worked as advertised. Focus speed was zippy – much faster than a 1.4X on a non-mirrorless body and the EVF remained bright. This attachment brought my full-frame lens a reach of 840mm. Moreover, if I set the A7R IV to APS-C mode, this combo gave me a reach of 1260mm. About as much as I would ever wish for.

Interestingly, this Sony lens is quite light. 4.5 pounds as compared to the aforementioned Sigma which weighs about 7 pounds. I was comfortable carrying it around without any support for stability. From memory, the lens offers about 3 stops of stabilization and the camera body another 5 stops. Lots of stabilization in other words. However, with the tele-extender attached, the overall weight increases and the 1260mm reach makes the tiniest wobble exaggerated. So I still use a monopod for increased stability.

In theory I could purchase a 2X tele-extender and have a reach of 1200mm for full-frame images with 61 megapixels. The lens opens to a max of F6.3 at 600mm and hence a 2X tele-extender would give me a wide open F-stop of 12.6, which makes me a little uncomfortable.

Currently both Sony and Canon are patenting designs for 100 megapixel sensors. It has been rumoured that Canon will offer a mirrorless body with such a sensor and likewise there is speculation that a successor for the A7R IV I have (presumably an A7R V) would also have a 100 MP sensor. This may seem crazy, but look at how tiny the sensors are on smartphones. The image quality of the cameras embedded in new smartphones is amazing. So a much larger sensor boasting 100 MP may not be crazy, but in fact be imperative in the face of smartphone still camera competition.

Alas, someday I’ll find a substitute for Flickr and use it to post photos to forums such as this one. In the meantime the reader will just have to accept my word that the images from the Sony gear are very good. And they can be “good” in two ways. Sharper with more detail, but also images of subjects that were simply too far away for photos. E.g., recently I came across a small flock of Canvasbacks which were foraging (diving) about 100m from a shoreline. With the Sony I was able to take acceptable photos, but the ducks were too far away for my old gear.
By northvanrob
Hi Mike,

I was really disappointed with Canon when they ended the 7D line, as that was the preferred camera body used by bird photographers!

I bet Canon lost many people because of that move, and have moved on, like you to Sony, who seems to to be very progressive in their camera evolvement!

Like you, I have been a Canon camera user since 1975, and have always gone with the Canon line!

Though they screwed me twice now, first one was changing to EF from FD!

I had just bought some great lens in the FD line, when they changed to EF!

I bought their first EF camera the Canon EOS 650! It was a plastic body!

I thought it was cheap!

The auto focus was terrible! You couldn't get it to focus like you could manually, like with the FD line!

So I drop photography completely, until the first real good DSLR came out, the Canon 10D

I don't know what direction I will take!

I am happy with the 7D MK II for now!

But maybe I'll switch like you!

I'm looking for a lighter system anyways!
User avatar
By BirdingBC
MDB8 wrote: Mar 30 8:24 pm Alas, someday I’ll find a substitute for Flickr and use it to post photos to forums such as this one. In the meantime the reader will just have to accept my word that the images from the Sony gear are very good.
Hi Mike, maybe I can help. Are you currently using any service to host or store images online? I am thinking if the photos are someone online, there might be way to share as is so you don't need to find another service. If all offline, then yeah, I understand the need to find a substitute. Maybe check out I use imgur as a backup when I don't want to pollute my Flickr account.


I had to get confirmation in another thread first,[…]

Thanks Kevin! That's great. I have a few other ph[…]

2021 BC Birding Video Challenge

Adding 4 new birds to the list! Virginia Rail […]

172 Birds and Counting! Auklet, Rhinoceros Bittern[…]