Odd Pointless lens comparison, SAL1650@70mm Vs Canon 70-300mm L @70mm on a A7RIII

So here we have a oddball, pointless, Adapted lens comparison.
The Sony SAL1650 APS-C @50mm , 70mm equivalent .
VS.
The canon 70-300mm f/4-5.6 L IS USM @70mm
On a A7RIII
Sony adapter LA-EA3
Metabones Ef-E smart adapter IV
Stock JPEGs from the camera
ISO 200
f/5.6



___________________________________________________________________________________________

First up the Sony SAL1650 @50mm x 1.4 APS-C equivalent 70mm







______________________________________________________________________________________________

And now the Canon 70-300mm f/4-5.6 L @70mm







Ultimately the Canon out resolves the old A mount kit lens.. However the SAL1650 holds it's own well, Especially considering it can open up to F/2.8
One of the things i found quite odd is.. while both lenses were set at f/5.6 the Canon lens exhibits a shallower depth of field. ( see the roof corner in both sample images ) This is possibly due to the Sony Clear Image 1.4 zoom expanding the focal field.

OldNoob007 said:

So here we have a oddball, pointless, Adapted lens comparison.
The Sony SAL1650 APS-C @50mm , 70mm equivalent .
VS.
The canon 70-300mm f/4-5.6 L IS USM @70mm
On a A7RIII
Sony adapter LA-EA3
Metabones Ef-E smart adapter IV
Stock JPEGs from the camera
ISO 200
f/5.6



___________________________________________________________________________________________

First up the Sony SAL1650 @50mm x 1.4 APS-C equivalent 70mm







______________________________________________________________________________________________

And now the Canon 70-300mm f/4-5.6 L @70mm







Ultimately the Canon out resolves the old A mount kit lens.. However the SAL1650 holds it's own well, Especially considering it can open up to F/2.8
One of the things i found quite odd is.. while both lenses were set at f/5.6 the Canon lens exhibits a shallower depth of field. ( see the roof corner in both sample images ) This is possibly due to the Sony Clear Image 1.4 zoom expanding the focal field.

Click to expand...

It may seem odd but it is the equivalence thing between APS-C and FF. To get the same DOF in FF shot you have to stop down one stop more than in the aps-c picture.

So, f/8 at FF and f/5.6 at APS-C have the same depth of field.

TimoKoo said:

It may seem odd but it is the equivalence thing between APS-C and FF. To get the same DOF in FF shot you have to stop down one stop more than in the aps-c picture.

So, f/8 at FF and f/5.6 at APS-C have the same depth of field.

Click to expand...

Great point

OldNoob007 said:

OldNoob007 said:

It may seem odd but it is the equivalence thing between APS-C and FF. To get the same DOF in FF shot you have to stop down one stop more than in the aps-c picture.

So, f/8 at FF and f/5.6 at APS-C have the same depth of field.

Click to expand...

Great point

Click to expand...

I think that's the point. ;-)

OldNoob007 said:

So here we have a oddball, pointless, Adapted lens comparison.
The Sony SAL1650 APS-C @50mm , 70mm equivalent .
VS.
The canon 70-300mm f/4-5.6 L IS USM @70mm
On a A7RIII
Sony adapter LA-EA3
Metabones Ef-E smart adapter IV
Stock JPEGs from the camera

Click to expand...

WHY Out of camera jpgs?

OldNoob007 said:

ISO 200
f/5.6



___________________________________________________________________________________________

First up the Sony SAL1650 @50mm x 1.4 APS-C equivalent 70mm







______________________________________________________________________________________________

And now the Canon 70-300mm f/4-5.6 L @70mm

Click to expand...

There's some Chromatic Aberration in this last Canon detail. I think it was easy to correct in the raw conversion if it was lateral CA but not so easy if it was longitudinal aberration ( but maybe possibly). Do you have the raw file of his picture?

OldNoob007 said:

Ultimately the Canon out resolves the old A mount kit lens.. However the SAL1650 holds it's own well, Especially considering it can open up to F/2.8
One of the things i found quite odd is.. while both lenses were set at f/5.6 the Canon lens exhibits a shallower depth of field. ( see the roof corner in both sample images ) This is possibly due to the Sony Clear Image 1.4 zoom expanding the focal field.

Click to expand...

TimoKoo said:

WHY Out of camera jpgs?

Click to expand...

Well a lot of corrections could be done in RAW with both images . But if one wants to keep 42mp with the APS-C lens then "Clear Image zoom" has to be used but sadly that can only be used in JPEG mode.
Crop mode results in a 18mp image which i suppose could be upscaled to 42mp in RAW.
OR the canon 42mp image could be down scaled to 18mp
Both those processes would be an interesting experiment.

Interestingly i don't think in camera corrections actually work with the adapted Canon lens.. what you're seeing with the canon lens is a uncorrected image.
However the SAL1650 with the LA-EA3 adapter in camera corrections does work.
Just another oddity

OldNoob007 said:

OldNoob007 said:

WHY Out of camera jpgs?

Click to expand...

Well a lot of corrections could be done in RAW with both images . But if one wants to keep 42mp with the APS-C lens then "Clear Image zoom" has to be used but sadly that can only be used in JPEG mode.
Crop mode results in a 18mp image which i suppose could be upscaled to 42mp in RAW.
OR the canon 42mp image could be down scaled to 18mp
Both those processes would be an interesting experiment.

Click to expand...

OK I'm out. I don't understand anything.

I don't not know what's Clear Image Zoom. I did think you used an aps-c camera and a ff camera to compare.

Now I think you used a7R3 in both of your shots, but with that magical "Clear Image zoom". If you did so, I think the comparison went pointless because everything became relative.

I apologize, I can't help further, unfortunately. :-(

OldNoob007 said:

OldNoob007 said:

WHY Out of camera jpgs?

Click to expand...

Well a lot of corrections could be done in RAW with both images . But if one wants to keep 42mp with the APS-C lens then "Clear Image zoom" has to be used but sadly that can only be used in JPEG mode.
Crop mode results in a 18mp image which i suppose could be upscaled to 42mp in RAW.
OR the canon 42mp image could be down scaled to 18mp
Both those processes would be an interesting experiment.

Click to expand...

Sony say "Clear Image Zoom is a feature that allows you to enlarge the image with a resolution close to the original image quality when shooting still images. The camera first zooms optically to the maximum optical magnification, then uses Clear Image Zoom technology to enlarge the image an additional 2x, producing sharp, clear images despite the increased zoom ratio." https://www.sony.com/electronics/support/articles/00021551

In this case that means that the camera takes the 18 megapixel image from the APS-C lens and resamples it to 42 megapixels. That obviously means the resampled image can't be saved as a RAW file. The difference between the camera doing this or doing it yourself on a computer is that the latter method generally gives you a choice of resampling algorithms.

OldNoob007 said:

Interestingly i don't think in camera corrections actually work with the adapted Canon lens.. what you're seeing with the canon lens is a uncorrected image.
However the SAL1650 with the LA-EA3 adapter in camera corrections does work.
Just another oddity

Click to expand...

Not really an oddity. DxO and other software providers analyse each lens they provide corrections for in order to design the corrections. It would be bad manners for Sony to do that to the Canon lens range and would perhaps imply that Canon had something to teach them about lens design.

Yep.. totally pointless

OldNoob007 said:

Yep.. totally pointless

Click to expand...

I thought you were teaching yourself physics.

You can take a Gfx camera and a zoom lens. Then you have fixed camera sensor, same lens. Then cycle through with crops to prove to yourself the depth of field and angle of view from micro four thirds to Gfx with crops and equivalent aperture.

Physics works and its not a bad way to understand things.

Many many many threads on dpreview get this wrong and mostly due to different sensor technology and wrong apertures. Or different lenses with different optical formula resulting in different drop offs in the focus plane.

Sittatunga said:

Sittatunga said:

Interestingly i don't think in camera corrections actually work with the adapted Canon lens.. what you're seeing with the canon lens is a uncorrected image.
However the SAL1650 with the LA-EA3 adapter in camera corrections does work.
Just another oddity

Click to expand...

Not really an oddity. DxO and other software providers analyse each lens they provide corrections for in order to design the corrections. It would be bad manners for Sony to do that to the Canon lens range and would perhaps imply that Canon had something to teach them about lens design.

Click to expand...

Yep indeed.
I guess what i was actually trying to say is that i was surprised the adapted A mount lens had in camera correction in the a7R3's lens database

Thankfully though, the Canon 70-300 L lens is so well made, that any corrections needed are minimal and often not even needed.
But it is darn heavy

F5.6 cropped to APS-C is not the same as F5.6 at full frame. For full equivalence you should be using the Canon at F8 or the Sony at F4. That's closer, anyway.

But, for your compared crops, which are the same number of pixels, the DOF should be the same.

The SAL1650 isn't a kit zoom, it's an upscale lens. The DT kit zoom is an 18-55 or 18-70. The 18-55 is not bad for a kit zoom either. It does particularly well for IR.

SQLGuy said:

F5.6 cropped to APS-C is not the same as F5.6 at full frame. For full equivalence you should be using the Canon at F8 or the Sony at F4. That's closer, anyway.

But, for your compared crops, which are the same number of pixels, the DOF should be the same.

The SAL1650 isn't a kit zoom, it's an upscale lens. The DT kit zoom is an 18-55 or 18-70. The 18-55 is not bad for a kit zoom either. It does particularly well for IR.

Click to expand...

Good points.
Although the SAL1650 was included as a kit lens with one of the a77II systems. a very good combo