Canon Community

MarjonM · ‎03-12-2023

Last week I used the SA control ring on the macro lens for the first time. (in combination with an R6). I found the effect interesting.

Today I wanted to continue practicing with this effect. Now the SA control ring suddenly stops working. The effect is shown in the preview, but when I take a photo, the effect is not present on the photo.

In the meantime I had gone from firmware version 1.6 to 1.8. As a test went back to 1.6 but unfortunately this did not help.

Does anyone else have this problem?

FloridaDrafter · ‎03-12-2023

I use it on an R5, although I also have an R6, I didn't update to 1.8 so I can't say if that messed with spherical aberration (SA).

As mentioned, aperture plays a big part in the effect SA has on the image. I suspect what you are seeing in the viewfinder is its effect at f/2.8. Your camera focuses at f/2.8 (or wide open) to maximize AF, no mater what aperture you have set, then when you take the shot the aperture you have selected is used. I don't think exposure simulation would work for SA, at least that is the way I understand it, and besides, ES is only available in live viewing from the rear LCD.

Attached are some "down n dirty" tests that I just shot with SA at -2. and varying apertures.

F/2.8 with no SA.

F/2.8 - No SA.

F/2.8 and -2 SA.

F/2.8 - Negative 2 SA.

F/4 and -2 SA.F/4 - Negative 2 SA.

F/6.2 and -2 SA.

F/6.3 - Negative 2 SA.

Note that there is very little change in the subject itself from f/2.8 no SA and f/6.2 -2 SA, however, the background is effected. If I had pulled back a little, you would see a more dramatic effect in bokeh at f/6.2.

I hope this helps.

Newton

View solution in original post

rs-eos · ‎03-12-2023

What function did you assign to the control ring?

--
Ricky

Camera: EOS 5D IV, EF 50mm f/1.2L, EF 135mm f/2L
Lighting: Profoto Lights & Modifiers

shadowsports · ‎03-12-2023

My understanding is the SA does not require assignment. Isn't it just a function of the lens?

~Rick
Bay Area - CA

~R5 C (1.0.7.1) ~RF Trinity, ~RF 100 Macro, ~RF 100~400, ~RF 100~500, ~RF 200-800 +RF 1.4x TC, BG-R10, 430EX III-RT ~DxO PhotoLab Elite ~DaVinci Resolve ~ImageClass MF644Cdw/MF656Cdw ~Pixel 8 ~CarePaks Are Worth It

rs-eos · ‎03-12-2023

Oh apologies; I had incorrectly been thinking of the front ring.

For the original shots taken vs the new ones, what were all the settings? Page 10 of the User Manual has several notes that the effect may be lessened depending upon several factors.

--
Ricky

Camera: EOS 5D IV, EF 50mm f/1.2L, EF 135mm f/2L
Lighting: Profoto Lights & Modifiers

shadowsports · ‎03-12-2023

Ricky, you kind sir have nothing to apologize for. I initially thought he was using a Control Ring as well. He hadn't mentioned his camera. I had recently read an article about this lens and remembered mention of the SA feature which is quite remarkable. I do not believe Canon has another lens that moves the entire objective group fore or aft to control the degree of sharpness the lens produces. I almost got the EF 100 way back when, but decided against it because I don't do much macro photography. I must admit the RF version is pretty cool. I always pay close attention to your C70 posts with the 0.71x adapter. I had no idea Canon made an adapter letting the C70 use FF glass and maintain the same FOV. You also showed me how important ND's are for video.

Canon improved the mag on this RF lens also. All of this only became important to me since purchasing the 100-500 with TC. Sorry for going off topic here.

~Rick
Bay Area - CA

~R5 C (1.0.7.1) ~RF Trinity, ~RF 100 Macro, ~RF 100~400, ~RF 100~500, ~RF 200-800 +RF 1.4x TC, BG-R10, 430EX III-RT ~DxO PhotoLab Elite ~DaVinci Resolve ~ImageClass MF644Cdw/MF656Cdw ~Pixel 8 ~CarePaks Are Worth It

MarjonM · ‎03-12-2023

I use the SA control without assigning an other function to it. The effect shows best at 2.8. When I use 5.0 I see the softness in the preview but no softness at all on the photo. As if I was not using the minus or plus.

shadowsports · ‎03-12-2023

@MarjonM wrote:
I use the SA control without assigning an other function to it. The effect shows best at 2.8. When I use 5.0 I see the softness in the preview but no softness at all on the photo. As if I was not using the minus or plus.

I could imagine. The softness of the bokeh balls and front / rear focus would be more pronounced and noticeable when more light is present.

I'm looking now, but I would assume the SA control diminishes as aperture decreases and less light becomes available. To what degree the softness/sharpness is adjustable is not clear. If you see it in the viewfinder or live view, I'd expect to see the same in your image.

**Edit. I did find this.

The SA Control effects will be greater when the lens is used at its maximum aperture. It is recommended to use either aperture priority or manual exposure mode in order to maintain as much control over the bokeh effect as possible.

~Rick
Bay Area - CA

~R5 C (1.0.7.1) ~RF Trinity, ~RF 100 Macro, ~RF 100~400, ~RF 100~500, ~RF 200-800 +RF 1.4x TC, BG-R10, 430EX III-RT ~DxO PhotoLab Elite ~DaVinci Resolve ~ImageClass MF644Cdw/MF656Cdw ~Pixel 8 ~CarePaks Are Worth It

MarjonM · ‎03-12-2023

At 4.0 I see softness in the viewfinder and live view, but not on the image. I don't know if it is suposed to be like that or not

shadowsports · ‎03-12-2023

Ken Rockwell states:

At f/2.8 the effect is strong as I show below, even at the most minor ±1 settings. That's OK; if you want a milder effect, stop down to f/4 or f/5.6 where the effects of the SA CONTROL become much less.

**

I suggest you try shooting in manual or Av mode.

~Rick
Bay Area - CA

~R5 C (1.0.7.1) ~RF Trinity, ~RF 100 Macro, ~RF 100~400, ~RF 100~500, ~RF 200-800 +RF 1.4x TC, BG-R10, 430EX III-RT ~DxO PhotoLab Elite ~DaVinci Resolve ~ImageClass MF644Cdw/MF656Cdw ~Pixel 8 ~CarePaks Are Worth It

MarjonM · ‎03-12-2023

thanks for your reply. I keep trying!

Canon Community

RF 100mm f2.8L Macro IS USM SA control ring not working