Any reasons to use APS-C lenses on a full-frame Panny body?

[Viv]

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2 hours ago, david strachan said:

Thank you Boojay.

Your explanation seems the only possibility.

I was hoping for a real "uncomputed" image.

...

Agreed.

And so was I.

[Boojay]

Yes I did check on my SL2 but unless I am being completely dim I don't think it is possible.

 

[michali]

7 hours ago, Boojay said:

 

My understanding is that when using an APSC L mount lens on the SL2, the camera automatically crops the image - there is not a way to see a full frame image.  Yes, if you chose to shoot in APSC mode with a full frame lens, the camera will show you the cropped image but the full frame will be saved.  I think Michali's image is a cropped image.

 

6 hours ago, david strachan said:

Thank you Boojay.

Your explanation seems the only possibility.

I was hoping for a real "uncomputed" image...

 

There are 2 different scenarios we're dealing with-

1. APSC L Lens on SL/SL2:

In the case of the image that I posted in post #16 - I've used an APSC lens (60mm TL) with a full frame camera. Everything that you see is what the camera's saved as a 20MP DNG. I believe that its been automatically cropped camera, that's the whole image, there's nothing more and nothing less.  The Jpeg that I posted is exactly the same as the DNG.

To illustrate the point, ( I normally shoot DNG & Jpeg), when reviewing the images on my computer, both the DNG & Jpeg appear on screen exactly the same size . See first image below.

2. Full Frame Lens in APSC Mode on SL/SL2:

It's an entirely different story when you use a full frame lens in APSC mode on the SL or SL2.  In that case the image is cropped to APSC size / magnified by 1.5x.  As Jayne says, the full frame image is still saved as a 47MP DNG, . 

To illustrate this, see 2nd image below, it's taken with the Sigma 45mm FF lens in APSC Mode on the SL2.  When the images are reviewed on my computer, the DNG appears on screen as the full frame vers. and the Jpeg appears as the APSC cropped vers.

So to answer the original question, when using an APSC L mount lens on the SL/SL2 the image is cropped in camera down to approx. 20MP , what you see is what you get in both DNG & Jpeg. No issues with image circle vignetting. 

Best,

Mike

1. APSC lens on SL/SL2:

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2. Full Frame Lens on SL/SL2 in APSC mode:

 

Edited March 18, 2020 by michali

[BernardC]

6 hours ago, Boojay said:

My understanding is that when using an APSC L mount lens on the SL2, the camera automatically crops the image - there is not a way to see a full frame image.

That is correct. The only way to see an uncropped APS-C image is by using an adapted lens instead of a native L-Mount lens. For instance, most historical cine lenses only cover Super-35 (4 perf) format, which is very close in size to APS-C.

I don't know if the the various "intelligent" adapters from Sigma and Novoflex pass-along the APS-C flag. Perhaps someone who has one of these adapters can try. "Dumb" adapters (those without electrical contacts) have no way of telling the camera if the lens is APS-C or full-frame, so the L-Mount cameras will save the full 24x36mm frame to the RAW file.