Sony Alpha A1 and the 24mm f1.4 GM lens.

Every January I run tours to northern Norway in the hope of seeing the Northern Lights. Over the years I have been incredibly lucky and to date, every single tour I have run has seen the Northern lights. I’ve taken all sorts of cameras on these tours, everything from optical disc camcorders (PDW-700), solid state camcorders including the original Sony EX1 and most of Sony’s large sensor video cameras from FS100 to the FX9.

All of these cameras are fairly bulky and require larger tripods and battery systems. In addition, I have always taken a stills camera to shoot timelapse of the Aurora. This year I decided to downsize the equipment I was taking, so instead of taking a full-size video camera I decided to take 2 small cameras.

I already have an FX3, which is a great camera and extremely good in low light. Being part of the Sony Cinema line, it has Sony’s very nice looking Venice based colour science as well, can shoot using S-Log3 as well as the handy what you see is what you get S-Cinetone gamma curve. I know this camera well and I knew it would be a good choice for the challenges I would encounter in Norway. To compliment the FX3 I also decided to take a Sony A1. The A1 (or Alpha 1) is Sony’s flagship compact mirrorless stills camera. As well as amazing photo performance the A1 also promises much as a video camera. It’s 50.1 megapixel sensor allows it to shoot high quality video at 8K. Like the FX3 the A1 can record using S-Log3 and offers similar dynamic range to the FX3.

Screenshot-2022-05-04-at-14.48.46-496x500 Sony Alpha A1 and the 24mm f1.4 GM lens.
Sony Alpha A1

Need for Speed – fast lenses.

For many years my main lens for shooting the Northern Lights has been the Sigma 20mm f1.4. This is a great lens, but it is quite heavy and I’ve never found the autofocus on this lens to be all that good. I already have Sony’s 20mm f1.8 and this is a great lens for the money. But for the Northern Lights you really want your lenses to be as fast as possible.So for this trip I decided to take Sony’s 24mm f1.4 GM lens to see how that performed.

24f1.4-600x411 Sony Alpha A1 and the 24mm f1.4 GM lens.
Sony 24mm f1.4 G Master lens – I really like this lens.

The other lens that I use extensively on trips like this is the much-underrated Sony 24-240mm zoom lens. This is a 10x zoom giving a huge range of focal lengths from pretty wide to nice and long. The aperture does ramp, going from f3.5 to f6.3 as you zoom in. But for the kinds of shoots I use this lens on this is rarely an issue. Todays cameras are so sensitive that f6.3 is plenty fast enough for all daytime applications. In northern Norway in the winter the temperature is typically -20c, often getting down as low an -35c. Changing lenses is not something you want to do unless you really must when it’s this cold, so a zoom lens is what I like to use when I’m out and about on the show scooters.

Shooting 8K with the A1.

Wherever I could I shot with the A1 in 8K. I recorded internally to CFExpress type A cards using the XAVC-HS codec. When shooting 8K at 24fps the file size is 7860×4320. It is 10 bit 4:2:0 and the bit rate is 400Mb/s. When you shoot 24p at 4K using the XAVC-SI codec the bit rate is 240MB/s, so you might wonder how it’s possible to record frames that in 8K are 4 times larger than 4K with a codec only half the size. The XAVC-HS codec is based on the latest H265 codec. H265 is an ultra efficient long GoP codec. Long GoP codecs can be very efficient as they record a master frame called an “I” frame and then for the next group of frames they only record the differences between the first “I” frame and the next “I” frame. The GoP (group of pictures) can be anywhere up to 180 frames long (but is typically 24 to 60 frames long). This method of compressing moving images is very effective and very efficient. But it can sometimes struggle with very complex images where there is a lot of random motion. Random motion cause issues for the motion prediction algorithms in the codec. In my own footage from Norway, I did notice some minor artefacts in the rippling water within shots across the Fjords.

mountain_1.3.1-600x338 Sony Alpha A1 and the 24mm f1.4 GM lens.
Filming water can be a real challenge for long GoP codecs, but the A1 did very well.

Moving water is always going to be tough for a Long GoP codec, But I suspect that unless you were actually looking for the artefacts most people wouldn’t notice them. When I graded the A1 footage I also found other very minor artefacts if I pushed the footage hard during the grade. But having said all of that, overall, I think the footage from the A1 looks pretty amazing.

One thing you really do need to consider if you are thinking of using the A1 to shoot 8K is that the XAVC-HS HEVC codec requires a lot of extra processing power to decode. So, your computer needs to be a fast one. Preferably one made in the last couple of years as the most recent processors and graphics cards now include special optimisations for the HEVC codec that will really help.

The sensor in the A1 uses Sony’s latest multi-layer stacked technologies. It is surprisingly sensitive and very low noise. It has excellent dynamic range, around 14 stops which is typical of most current large sensor cameras and very pleasing colour response.

dog-sled_1.11.1-600x338 Sony Alpha A1 and the 24mm f1.4 GM lens.
Frame grab from the Alpha A1.

 

The camera performed better than I expected in low light and while for me at least the A7SIII/FX3 and FX6 remain the kings of low light, the A1 isn’t actually all that far behind. This is particularly impressive when you consider that the pixels in the A1 are much smaller than the pixels in the A7SIII. Having said that, it does appear that the A7S3/FX3/FX6 sensor combines 4 photosites under a single colour filter to create a single “pixel”  – could they both be based on a very similar sensor? The A1 sensor is 8640 x 5760 while the A7S3 sensor is 4240 x 2832, the numbers are close enough to believe the underlying sensor could be the same.

For a camera with so many pixels the A1 has a very low level of rolling shutter, you are highly unlikely to encounter any significant rolling shutter issues thanks to the 16ms readout time at 8K. Again, it is interesting to note that the 8.7ms readout of A7S3/FX3/FX6 at 4K is almost exactly half that of the A1 – further pointing to sensor similarities.

Golden Hour = Golden Day.

One of the great things about Norway in the winter is that when the skies are clear the very low sun means that you get golden hour light almost all day. The A1 did an excellent job of capturing the rich colours and deep shadows, especially that deep orange light that seems to make objects glow. Rather than going for a film style grade I chose to use a high contrast and vibrant grade for the sample video. I edited the footage in DaVinci Resolve using ACES colour management. The initial grading was done in HDR and I have uploaded an 8K HDR version for those of you that have an HDR TV or monitor.

sunset_1.15.1-600x338 Sony Alpha A1 and the 24mm f1.4 GM lens.
Beautiful golden hour colours captured by the Sony A1



The days in northern Norway in January are very short and brutally cold. You only have to look at the shots of the dog sled driver to see how well wrapped up he is. It got down to -34c the day we went dog sledding. Even without a cover the A1 performed very well in the cold. There was some loss of battery life but this is to be expected. If you do find yourself shooting somewhere very cold, try to keep your batteries in an inside pocket until you need them to keep them warm.

At night I decided to use the A1 to shoot time-lapse of the Aurora while using the FX3 to video the Aurora. The A1 has a built in intervalometer so it’s very easy to shoot timelapse with it.

The 24mm f1.4 GM lens.

A1_06304-600x400 Sony Alpha A1 and the 24mm f1.4 GM lens.
A frame of the Aurora taken with the A1

 

Shooting stars at night with a wide angle lens is very challenging. You have to be very careful to ensure that your stars and in good focus. I use the cameras built in image magnification to check and double check my focus.  One thing that many wide lenses suffer from is an optical defect called “coma”. Often stars that should be a tiny round point of light will take on a slightly elongated appearance, looking like a comma sign or comet rather than a dot, especially towards the edges and corners of the frame. My Sigma 20mm has very little coma and it’s one of the reasons why I like it so much. But the Sony 24mm f1.4 has even less, in fact it is almost completely non-existent. The 24mm is also very, very sharp even wide open, there is no need to stop down to sharpen the image as with some other lenses. It is also a very compact lens and yet despite its small size and low weight it manages to fit in a proper iris ring as well as the large focus ring. Like most of Sony’s most recent lenses the 24mm GM has a linear focus ring. Linear focus means that the amount you turn the focus ring for any given focus change remains completely constant. As a result, you can manually pull focus from one object to another very easily as each time you shift the focus back to your starting point the focus ring will return to exactly the same position each time.

While not quite as wide as my 20mm the clarity and lack of distortions in the images from the 24mm GM means that this lens is now easily my favourite lens for shooting the Aurora or star fields. Of course, it is also very competent for shooting during the day as well. The autofocus is very fast and completely silent due to the use of linear focus motors. The extra assignable button on the lens body is also very handy.

trees_1.5.1-600x338 Sony Alpha A1 and the 24mm f1.4 GM lens.

Together the A1 and the 24mm GM were a delight to use. I have to admit that I am wondering whether an A1 could replace my FX3 or FX6. The richness of the 8K images from the A1 are impressive to say the least. I have done a few 8K projects for clients already, But I am not yet regularly delivering in 8K and I don’t think it will be something that I will be asked for regularly for a couple years yet. Besides, most of my clients that do want 8K are really going to want me to shoot on a Venice 2 rather than the A1. I also don’t think I can push the A1 8K images in post quite as much as I can the XAVC-S-I or XAVC-I from the FX3/FX6. Plus, when you do start to do any heavy image manipulation at 8K even my MacBook M1 Max starts to bog down (I actually find it easier to work with the 8K XOCN from Venice 2 than the 8K XAVC-HS from the A1). The FX3 will remain my main camera for my Aurora shoots for the next couple of year but perhaps I will need to start saving some pennies to add an A1 to my camera collection, it certainly impressed me and it would be nice to start shooting some of my stock footage in 8K.

NOTE: To watch the video in 8K you will need a monitor, TV or device capable of 8K playback. To view in HDR you will need to be using an HDR TV or HDR monitor. If you do not have an 8K or HDR TV/Monitor then YouTube will detect this and instead send you a standard dynamic range verison of the video at the highest resolution that your device can support. For the best viewing experience please watch using a HDR device that supports HDR10 ST2084/Rec2020.

3 thoughts on “Sony Alpha A1 and the 24mm f1.4 GM lens.”

  1. Hi Alister

    As far as I know, the artifact you are referring to is coma, not comma; referring to comatic aberration, like the tail of a comet.

  2. Beautiful images Alister ! I could only see in 4K but non the less spectacular. I am glad you used the 24-240 so I could see the result. I too have that lens and agree it’s underrated. I use it( 24-240) on my FX6/FX3 in 4k when shooting wildfires. It beats changing lenses in the middle of a fire and the quality is quite good.
    Cheers!

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