step-up ring and Xume magnetic filter holder

[tradershighway]

 Hi

After no issues with a Crop sensor Sony A6300, I have now use a Sony A7ii.

I use filters with a step-up ring to save cost. I also use Xume magnetic filter holders for ease of use. When using the Xume and step-up ring with Polarizer or ND filter on the the A7 it can not get Focus even manually. the step-up ring is 49-62mm, the lens is Sel28F20, the filters Hoya Pro1. I have heard of vignetting with step-up rings but that is not an issue due to the large step. I can not find anything on the Net about not focussing. The crop sensor camera works fine, the step up and filter work fine together, but not when I add the Xume holders, I cnnot focus. I would really like to continue wth the Magnetic holders for ease of use and they cost a lot of money. Any help would be appreciated.

Paul

[leotroll]

Hi ya. 

          A7 series focus issues with certain lenses -- the Community

                                                                                                         Put that in your internet browser whether it will help or not don't know? ,worth a look anyway.

                                                                       Theres  a post below yours relating to shooting at f8 ,thats with afc though,but it lets you know whats happening relating to the way the lenses are working. The post is - A7r11 really bad tracking in afc for all users.

                                                  Think sony changed the way focusing worked  on A7 series cameras to combat focus shift.

[tradershighway]

Thanks for the reply.

I think the problem is that the filter fitted in this way fools the camera into thinking the fisheye converter for this lens is fitted and that is why it will not focus. When I load the image into Lightroom it states the converter is fitted. When I select the lens without the converter in LR the image is better but still blurred as this is what the saved digital file data contains.

[leotroll]

hi ya. 

         If it works fine on the a6300 have you tried using it in crop mode   ,i don't know if you can activate this via the menu for added telephoto reach, or if its automatically related to attaching an apsc  lens,i assume when you used it on the a6300 it was with the 28mm f2, thats the lens i use as my standard on my a6000.

[tradershighway]

Thanks for the reply.

In crop factor mode the megapixel size is more than half of full frame size and the quality greatly reduced. Makes no point to upgrading to full frame really. Bottom line is the camera should not do this so I have logged a support issue with Sony. Thanks again for your feedback.

[leotroll]

hi ya.

          Was just thinking that it may reveal the uderlying cause.If images came out  in focus as on the a6300, maybe be an indicator to the problem .Would also be interesting to see if the teleconverter fitted statement would occur in crop mode. 

[tradershighway]

Took your advice and did various testing between the Sony a6300 and the Sony A7ii.

In crop factor mode on the A7 still could not obtain sharp focus.

The problem was still there using the Full frame lens on the A6300

If I use the 6300 and the crop factor Sigma DN lens works great.

So the issue is with recognition of the lens with Filter + Step up ring + Xume holders. I can only presume the extra thickness somehow fools the camera to thinking it has the Fisheye converter attached. I think there would not be a problem if this lens did not have 2 avai;able converters that have to be programmed into the software. The reason I think the thickness is an issue is the filter plus step up ring work fine, and the Xume holders plus the filter work fine, it is when the 3 are together the issue shows itself. But this setup is working fine the world over on Cannon, Nikon ect

One annoying fact that has come out of this is the 6300 with Sigma DN lens has much better image quality than the A7ii even when not using the filters.

I was advised to reset the camera to factory, but given the error is evident on the 6300 as well with the full frame lens, I do not fancy this.

[tradershighway]

Typical Sony Customer support response. 

If the lens works fine without a filter, the problem is mine to solve not there's.

[leotroll]

hi ya.

        Really weird the way that worked out,you would never have thought that would occur.Thanks for posting ,especialy for everyone like myself using the 28mm f2. 

                                                                                                   I'm not surprised about image quality with the sigma dn lens ,i had the  sigma dn 60mm f 2.8 lens used on an oly em1, it was superb and cost peanuts.If i hadn't bought the 50mm f1.8 would definitely have that now.