Sony 85mm 1.8 vs Sirui 85mm | Best Budget Sony 85mm for Video
Introduction
When it comes to budget Sony 85mm primes, the Sony 85mm 1.8 seemed like the best value. However, Sirui has just released a new 85mm lens, that's even faster at f/1.4 at about the same price.
Let’s do some tests, and I’ll tell you what I think of these lenses at the end.
Specs
First off, here are two spec tables for these lenses. You can pause this if you’d like to read more, but the specs that jumped out to me were the price, aperture, size, and weight.
Build Quality
One of the reasons the Sirui was on my radar in the first place was because of it’s aperture and price point. It’s a f/1.4 instead of the 1.8 like the Sony - but costs the same amount of money. The Sony can go up to f/22, while the Sirui’s maximum aperture is f/16.
Another great feature of the Sirui is the declickable aperture ring, this is great for video. But more on video in the autofocus section about this.
To me, both of these lenses score about the same in terms of build quality. The Sirui feels more sturdy, but thats only because the lens is heavier. The G-masters are built better, but also cost more too.
The Sirui does have larger switches on the lens and the AEL button is this raised rubber button that is very clicky. I don’t know how to describe this any differently, but it’s very tactile for a lens button.
Not a huge difference, but it is a difference. The Sony lens is smaller and lighter though. Both have 67mm front threads.
Autofocus
(Check out the video for the autofocus test)
In the lowlight test, the Sirui 85mm really struggled with finding focus without racking back and forth.
The Sony 85mm 1.8, was able to grab focus without hunting for focus, but was also not reliably staying at the point I tapped on the screen. It would shift slightly after I tapped on where I wanted to focus.
Still a big improvement over the Sirui, but not quite as perfect as the Sony 85mm GM II - but this lens is about 1/3rd of the price of the G-Master. For the price, I think the Sony 85mm 1.8 is doing very well here.
(Check out the video for the natural lightautofocus test)
For the natural light autofocus test, I tracked my wife walking away and to the camera in sunlight and both lenses seemed to be doing a good job here. Both were able to use face and eye detect, and smoothly follow her movements and keep focus without hunting.
The hunting of the Sirui lens seems to happen more in low light situations or when focusing quickly. If you mostly shoot in brighter and ideal lighting conditions, you might not see a big difference in how these lenses focus.
For photo autofocus, I shot a burst of 17 photos of my wife turning around and the Sony got 16 or 17 photos in focus. The Sirui got 15 of 17 photos in focus, but 6 photos the photos were focusing on her hair instead of her eyes. For the price, I’ll let you decide if that is acceptable. For comparison, the Sony 85mm GM II costs $1800 and got all of them in focus, while one was focusing between her hair and her eyes. So even the most expensive lens isn’t perfect. Pretty close, but not perfect.
Focus Noise
When it comes to focus noise, both of these lenses are slient. Only saying this because the original 85mm GM had some focusing noise when using autofocus.
Color Cast
When it comes to color cast, let’s check out the results of the color chips and vector scope. The closer these color are to their boxes, them more accurate their colors are.
Starting with the Sony, most of these colors are pretty close to the boxes. This is a pretty accurate and neutral look, magenta skews a little more red. Green has a little more yellow in it. For me, these are pretty neutral colors.
Onto the Sirui 85mm, this lens skews much warmer than the Sony. Almost all of the colors are not hitting the boxes, and skewing towards yellow, magenta or red.
If you like warmer tones in your images, the sirui will fit your workflow. I could see portrait photographers maybe liking the warmer colors of the sirui. Personally, I would rather shoot a neutral image and color grade the image how I would want it in post, so I prefer the Sony here.
This one comes down to personal preference, but I prefer the Sony 85mm.
Distortion
When it comes to distortion, both lenses had some distortion.
The Sony has some very slight pincushion distortion at the top and bottom of the frame. For what it’s worth, I’ve used this lens and never noticed it until I shot a photo of my grid cutting mat.
The Sirui has noticeably more pincushion distortion around all edges. We can also see the color cast here. The white balance was set to 5600k for both of these images.
For comparison, the G masters unsurprisingly handled distortion much better.
For portraits where you’re not filling the frame with the subject, this may not be as big of an issue, but if you’re trying to shoot natural images, the distortion may look strange if you put subjects near the edge of the frame.
85mm vs 85mm
For the field of view, both of these lenses are 85mm, and they are both have the same field of view, minus distortion.
Only saying this because the G-masters had a slightly different field of view. The GM II was slightly wider than the GM, and the GM is a little bit wider than both of these lenses. This probably isn’t enough to sway a decision between these lenses, but something I ran into.
Flaring
For flaring, I did a pretty phone flashlight test, it looked pretty uneventful. Both lenses had some flaring, but not really enough to wash out the entire image. Sirui appeared to be a little warmer, while the Sony was cooler.
Bokeh
For bokeh, we can see the Sirui’s faster aperture here. The Sirui has more bokeh at f/1.4 - as you would expect. At 1.4 the contrast is also lower on the Sirui 85mm.
The Sirui’s bokeh seems to be more clear and precise, and the Sony seems to be a little more blurry here. The Sirui does have 15 aperture blades, while the Sony has 9.
Sharpness & Image Quality
For sharpness and image quality, let’s quickly go over some charts.
The Sony 85mm was sharper than I expected it to be. Wide open, the center is sharp, while the edges are a little soft, but by f/2 the corners sharpen up. This lens does have a vignette until f/4. Chromatic aberration is noticeable in the center and edges at 1.8, less at f/2 and 2.8 I’m not able to notice it.
The Sirui 85mm the first think I noticed was the chromatic aberration in the center wide open. The center looks soft, due to the amount of chromatic aberation. The center is sharp at f/2 and the edges sharpen up at f/2.8. The center ca is gone between 1.8 and 2, but the edges of the frame have some at all apertures. This lens has some vignette until f/2.
If you’re shooting charts with the Sirui, you’ll notice the chromatic aberration but for portraits this translates to some of the edges of your shots looking soft wide open. Shooting at 1.8 or 2 will get you the sharpest results with the Sirui.
The Sony was sharp in the center at 2, and was able to sharpen up the edges at f/2.8. So while the Sirui is technically faster than the Sony, they both give sharp results at the same apertures which was pretty interesting.
Minimum Focusing Distance
For minimum focusing distance, I had a whole long winded section about this, but I’ll cut it down here. The Sony’s advertised minimum focus is 31.5, but I measures 31.25 with my tape and laser.
More interesting, the Sirui’s advertised minimum focusing distance is 33.5 in, but I measured 31.5.
So even though on paper, both of these have slighty different minimum focus, I measured differently and they are pretty much the same.
Focus Breathing
For focus breathing, I did not notice any focus breathing in the Sony 85mm 1.8.
On the sirui, I noticed that due to how it focuses, if you’re doing focus racks it finds focus then focuses past where is in focus and then comes back into focus. This is more apparent in low light situations, but if you’re using these lenses for video, I think the focus breathing of the Sirui is distracting to me.
Stabilization
For stabilization, both of these lenses do not have any optical stabilization.
Conclusion
When it comes to which of these lenses I would choose, I shoot a lot of video, and the Sony 85mm 1.8 does a better job at focusing especially in low light than the Sirui. The Sony does not have any focus breathing, less distortion and more neutral colors as well.
The case for the Sirui, is that if you are a portrait photographer and actually like the warmer colors, distortion and want a faster aperture. Keeping in mind that wide open it will be a little soft, but if thats what you want, the Sirui is a great lens.
For me, I’m sticking with the Sony.
Which of these lense would you choose?
Let me know in the comments on YouTube!