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

[MarjonM]

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?

[rs-eos]

What function did you assign to the control ring?

[shadowsports]

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

[MarjonM]

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.

[rs-eos]

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.

[shadowsports]

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@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.

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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.

[MarjonM]

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]

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. 

[MarjonM]

thanks for your reply. I keep trying!

[shadowsports]

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.