The 135mm should yield slightly more blur compared to the 85/1.4 GM when both are wide open and the 85mm image is cropped to 135mm.
Here is how they compare when moving the 85/1.4 GM closer to the subject to match the 135mm FOV. As you can see the relationship between subject and background changes.
Which do you prefer in terms of rendering? I find them similar under this scenario.
No particular preference here. I guess you’ll need to create either:
- bokeh balls, all the way to the frame edge
or
- a scene where the particular size of the background objects, as rendered by the different FLs, may prove advantageous to one of them
or
- some background that is particularly prone to creating “double vision” / “doubled edged” contours
So, when cropping the 85/1.4 GM to match the 135/1.8 GM's field of view, imo, the latter yields a bit more blur, much higher resolution and much better color aberration control. (Not to count it will be a 18MP image with about 1 stop worse dynamic range and noise levels)
However, when matching the 135mm FOV by moving closer to the subject, the 85/1.4 GM seem to offer a bit more smoothness at close inspection. This is even noticeable when comparing resized images side by side.
Here is what counts is I get the look of the 85 1.4 that I did not have. So I really find no need to get the GM 85 since I can get that look that the Sony 85 1.8 and Batis 85 did not give me . Now I still may see how the Samyang is but I’m not fighting the AF speed if the GM 85 but I can still get that look just get back further.
When changing distance (by moving the 85/1.4 closer) and equally framing the same subject, the 85/1.4 GM seems to have an edge in rendering (for the background) due to its SA under-correction.
It's even more evident here with the background closer to subject:
What I see is a slight advantage in rendering for the 85/1.4 GM for the background. (in detriment of foreground bokeh)
On the other hand, the 135/1.8 GM's rendering is also pleasant to my eyes with a more even background/foreground bokeh quality. (neutral bokeh)
Fred Miranda wrote:
When changing distance (by moving the 85/1.4 closer) and equally framing the same subject, the 85/1.4 GM seems to have an edge in rendering (for the background) due to its SA under-correction.
It's even more evident here with the background closer to subject:
At the same magnification DOF is smaller with the 85/1.4GM, which shows in the background. The biggest drawback of the 85 is AF speed though. Perfectly fine for normal situations, but if you need it quicker, it gets difficult esp. in dim light.
Holger wrote:
Blur is increasing with the 135, thats true (according to the simulator at around 12m the 135 increases the blur disks over the 85). But
DOF = 2 N C d^2/ f^2 with magnification f/d (d distance to subject, f focal lengthm C circle of confusion, N f-number).
So DOF is always smaller for equal m but smaller f-number.
Totally true, but the question is also how much compression do you want. Because the 85 has a smaller f-number it will always have more blur framed the same way, but it will have less compression. If you want less compression that is great. If you want more compression then you have a tradeoff, less blur but more compression with the 135. Both lenses are great and have their place.
Stoffer wrote:
The 135 is doing surprisingly well compared to the 85 GM. I would have thought the 85 would have a clear edge in rendering. This is great.
Thanks Fred!
That's my assessment as well.
I thought the 85/1.4 GM's rendering would be vastly superior because it's a lens designed for portraiture with bokeh rendering as a top priority. We all love its SA bokeh.
So, FE 135/1.8 GM's AF and higher resolution/contrast permits it to be used for many other applications like action, sports and portraits in movement but we can all agree that it doesn't entirely match the 85/1.4 GM's background rendering...The surprise for me was how close they were.
GMPhotography wrote:
I like the compression of the 135.
The 135 looks to pop slightly more
Interesting cause in most cases I prefer the compression of 135mm which is why I shoot it more often but in that particular shot I feel the 85mm pops more. Go figure
