EOS M6 What would cause the preview to look better than the shot? (both on the Camera's LCD Screen)

[robertkjr3d]

So I have a EOS M6.  And I have an 'EF Adapter'... Attached to that is a 'Canon EF 24mm 1.4 L Ultrasonic'.  This lens has some age, and I hope your not going to tell me that it may have gone bad.  However, I would get a decent picture on the LCD screen... then click the screen to take the shot.  Then it would show me the shot:  The resulting shot would then come out, not nearly has good (and I don't mean I took it to computer monitor to compare, I mean right there on the same M6 LCD screen).  I was like huh?!  I just saw a great image.  How come you can show me a great image, but can't save one?  Sometimes I was shooting 'M'.... sometimes I was shooting fully 'Auto'.  But unfortunately the best shots I was getting were not with this lens.  My other thinking is, that I'm missing some, or have changed some setting on the M6 camera body that is ruining the resulting picture.  This older still rather expensive EF lens is supposed to be still nice for shooting at night, and darker indoors.  The other item that could be to blame is the 'Adapter', but people have not had trouble with it, in the reviews.  I have the brand marked 'Xuerebs'... Yes a Chinese brand to be sure.     Help....

[rs-eos]

Have you set the camera to add any creative effects to images?  In this case, try resetting the camera back to default settings.

It doesn't sound like this is an adapter issue, but in general, you'd be better off with Canon-branded adapters.

[ebiggs1]

Ricky is correct a full reset and trash that adapter. Do a full rest not just half of one. Plus I would stay out of M mode until you get this sorted. Stay in P mode for now.

[robertkjr3d]

Now that I've got it home and looking at the resulting images. All the low-light shots are pretty poor (with that lens).  Like the camera is not able to auto-focus (when I take the shot...) and the lighting is not quite the same as the preview, as already mentioned.  I know the preview is sometimes a guess based on ISO settings.  I will try some more tests.  in low-light conditions.  and make some changes.  But hey maybe the Adapter is to blame.  Obviously I'm shooting in 'M' to actually fine-tune the lighting conditions.  where flash isn't going to be desirable or useful...

[ebiggs1]

I still prefer you do the full reset and use P mode for any "testing". Good luck.

[robertkjr3d]

As an update:
The 24mm EF L lens used to be paired for years with my SL2.  So I used that for testing.
So I took similar low-light shots at similar angles.  The results were not improved between the two cameras.  I was still having trouble with focus.  I did contact the Chinese-Ebay company who sold me the Adapter.  I had purchased 'Viltrox', but they admitted they sold me 'Xuerebs', they claim it is the same build quality.  And I can 'possibly' agree that the problem is not the adapter.  People have 'sworn' by 'Viltrox' adapters.  I think I may be having issues with the 'lens' itself.  

I then tested between the "EF-M 22mm f/2 STM" vs adapting "EF 24mm f1.4 L USM".  And the 24mm was losing in many conditions.  I think this is because of its condition.

I checked this thread: https://support.usa.canon.com/kb/index?page=content&id=ART167392  I wondering if servicing is what I need, or worth it.

[Waddizzle]

The resolution of the rear screen is not that great. It is most useful for checking exposure not image quality.  If you are shooting in low light conditions, then image quality may suffer.  Test the camera and lens outdoors on a sunny day. 

if you feel the images are still low quality, then please post a sample with exposure settings. 

[robertkjr3d]

well, I learned that I needed to use 'Manual' focus and hit the 'zoom' finder.  The auto-focus wasn't working in low-light conditions (which may not be out of the ordinary). 
So maybe this is all user error.  The Zoom does use the 'rear screen'.  This does seem a bit finicky, and that's what prompted this initial post.  I'll keep on it.  Thanks for all your posts.  perhaps with the added pixel density it becomes even more difficult to use.

[deebatman316]

Is the camera not locking focus AT ALL. Or is AF simply not working in low light conditions at all. With the camera set to One Shot AF. The camera should project an LED AF Assist from the camera body. When in low light or low contrast situations. Only the Canon 320EX can provide an AF Assist Beam on the EOS M series. The speedlite 320EX uses a bright white LED light for AF Assist. It can't use the red grid/ "IR" (not actually IR its just a red grid) AF Assist Beam that DSLRs use. The EOS R Series uses Intermittent Flash Firing from the speedlite to assist the camera in low light. Are you using the 1st Party EF to EF-M adapter. Or a 3rd Party EF to EF-M. 

[robertkjr3d]

The camera is locking focus.  I believe my problem was: I was not understanding the sheer weight of this lens with the adapter... plus the simple 'shutter speed' being too high causing double exposures.  Needing to lean tricks to hold the camera better or rest on wall or something if the 'shutter speed' must be so high.  Thanks.  Some night photos from that "art" trip actually came out better than I expected, when I got back to the computer.  At first I thought all of the 24mm lens night shots were gonna be toss outs.