Sony RX100 Mark 4 vs Mark 7 Lens Quality

[John Hollenberg]

I am looking for any experiences comparing the quality of the lens on the Sony RX100 Mark 4 and the Mark 7.  The reason for my question is that I own the RX100 Mark 4 and have been very satisfied with the quality of the lens, fairly sharp right to the edges/corners at f4 and f5.6.  I recently purchased the Mark 7 from B&H and did a quick test comparing my copy of each camera.  In the 24-70 range my copy of the Mark 7 had significant softening at the edges/corners at the same apertures shooting the same scene with the same settings on both cameras.  While the test was done handheld, at 200 mm the Mark 7 was very sharp so I don't think there is a problem with image stabilization (plus shutter speed was 1/1600).  The difference in lens quality was enough that I decided to return the Mark 7.

My question: did I get a bad copy or is this due to lens design?  Trying to decide if I should buy another Mark 7 locally and test again as I would like the extra zoom range and don't need the wider aperture offered by the Mark 7.

[John Camp]

I would also like an answer to this question so I'm bumping it up.

[kers]

I am looking for any experiences comparing the quality of the lens on the Sony RX100 Mark 4 and the Mark 7.  The reason for my question is that I own the RX100 Mark 4 and have been very satisfied with the quality of the lens, fairly sharp right to the edges/corners at f4 and f5.6.  I recently purchased the Mark 7 from B&H and did a quick test comparing my copy of each camera.  In the 24-70 range my copy of the Mark 7 had significant softening at the edges/corners at the same apertures shooting the same scene with the same settings on both cameras.  While the test was done handheld, at 200 mm the Mark 7 was very sharp so I don't think there is a problem with image stabilization (plus shutter speed was 1/1600).  The difference in lens quality was enough that I decided to return the Mark 7.

My question: did I get a bad copy or is this due to lens design?  Trying to decide if I should buy another Mark 7 locally and test again as I would like the extra zoom range and don't need the wider aperture offered by the Mark 7.

I woulde say : redo the test with a tripod ; it is so easy to make a mistake yourself.

[John Hollenberg]

I woulde say : redo the test with a tripod ; it is so easy to make a mistake yourself.

Shooting handheld at 1/1600 second would not cause a camera to produce images that are sharp in the center but lacking in sharpness at the edges/corners at multiple focal lengths.

[Jonathan Cross]

John.  Were you using IS at 1/1600th sec?  I was taught by a professional not to use IS at quicker than 1/500.

Best wishes,

Jonathan

[John Hollenberg]

John.  Were you using IS at 1/1600th sec?  I was taught by a professional not to use IS at quicker than 1/500.

IS was on for both cameras.  Mark 4 produced photos sharp throughout, the Mark 7 had significantly less sharpness at the edges/corners.

[BJL]

To combine above suggestions: testing on a tripod with IS off could help by eliminating some possible extraneous factors from the comparison.

[SrMi]

Mark IV and Mark VII have different max lens aperture. You may have shot VII wide open while shooting IV stopped down. Do you remember at what focal length/aperture did you make the test?
In DPR’s studio scene Mark VII did not demonstrate inferior corner quality.

[John Hollenberg]

Mark IV and Mark VII have different max lens aperture. You may have shot VII wide open while shooting IV stopped down. Do you remember at what focal length/aperture did you make the test?
In DPR’s studio scene Mark VII did not demonstrate inferior corner quality.

As I said, I used identical settings, in this case f4.  I shot multiple focal lengths (24, 35, 50, 70, 100, 135, 200).  The 200 looked really good, the 24-70 were soft at the edges/corners for the Mark 7 when compared to the Mark 4.  I don't remember about the 100 and 135 but since the Mark 4 doesn't have those nothing to compare.  It was immediately obvious in lightroom when both were zoomed to 100%.

[SrMi]

As I said, I used identical settings, in this case f4.  I shot multiple focal lengths (24, 35, 50, 70, 100, 135, 200).  The 200 looked really good, the 24-70 were soft at the edges/corners for the Mark 7 when compared to the Mark 4.  I don't remember about the 100 and 135 but since the Mark 4 doesn't have those nothing to compare.  It was immediately obvious in lightroom when both were zoomed to 100%.

This means that from about 45mm and longer you shot with Mark VII wide open, while you tested stopped down with Mark IV.
Lenses typically perform better when stopped down. The wider aperture on Mark IV and different zoom range makes it essentially a different camera than Mark VII.

[John Hollenberg]

This means that from about 45mm and longer you shot with Mark VII wide open, while you tested stopped down with Mark IV.
Lenses typically perform better when stopped down. The wider aperture on Mark IV and different zoom range makes it essentially a different camera than Mark VII.

The performance wasn't any better at 24 and 35 mm where the lens was stopped down.  My guess is that it was a bad copy of the Mark 7 as I haven't seen other reports of this problem.  That is why I started the thread to find out if anyone else is seeing a problem.

[Kiwi Paul]

I have the RX100 MK6 which has the same lens and I've not noticed any issues with sharpness in the corners at any focal length.
Overall I'm very impressed with the camera

.

[John Hollenberg]

I have the RX100 MK6 which has the same lens and I've not noticed any issues with sharpness in the corners at any focal length.
Overall I'm very impressed with the camera

Thanks for the first response that addresses my question!  If I buy another copy of the Mark 7 (likely) I will report back to this thread.