S1R II with Hybrid Zoom - Image Size - RAW

[CharlesH]

The native image size for the S1R II is 8144 x 5424. Hybrid Zoom reduces the image size as a lens is optically zoomed; the combined effects of the optical zoom and the reduced image size give the effect of extending the zoom range of the lens. This is a discussion of the image size versus the amount of Hybrid Zoom.

Lumix S series cameras report this effective focal length as the lens is zoomed. I have taken a look at what the image size is for various effective focal lengths on a couple of zoom lenses. I've looked at this for JPEG images; and also Lightroom Classic has the ability to look at the image size for RAW Hybrid Zoom images that were taken simultaneously with JPEGs.

These Hybrid Zoom settings were used:
Hybrid Zoom(Photo) ON
Effect at Wide Angle(Photo) OFF
Minimum Image Size S
Set Recording Image Size OFF

For Hybrid Zoom to function, Rec. File Format(Photo) must be set to record JPEG (or HEIF) or RAW+JPEG (or HEIF). Hybrid Zoom will not function with only RAW set. However, when both RAW+JPEG(or HEIF) are used it is interesting that the un-cropped RAW image is recorded and the crop information is added to the EXIF data for RAW. Lightroom takes advantage of this EXIF data and displays the RAW image as cropped. The JPEG does not need to be downloaded to Lightroom, just the RAW.

As far as I know Lightroom is unique at this time and other photo editors only display un-cropped RAW images. Here is what the Lightroom Develop screen looks like for a RAW Hybrid Zoom photo, with the Crop and Straighten tool selected. Note that the full un-cropped image is displayed, and the Hybrid Zoom cropped region is highlighted. Also I had previously moved the Hybrid Zoom cropped region - it is NOT centered - I moved the crop zone of the image a little to improve the framing. (Also note, at this point the cropped region can be modified to any size , shape and position desired - with the Hybrid Zoom crop as a starting point.)




Now looking at Lightroom's Library view, the zoomed RAW image is displayed, indicating the image size. Note the cropped image size is at the upper left, 4128 x 2748. While the captured image size is shown in the data at the right, 8144 x 5424.




I looked at two lenses, the 24-60mm and the 70-300mm, and took photos varying the Hybrid Zoom focal length indicated by the camera in steps from full wide angle to full telephoto. I noted the actual lens optical focal length for each Hybrid Zoom focal length as shown in Lightroom. And then I used Lightroom to measure the actual image size for both the JPEG images and the RAW images. Here is a table with that data. Note that the JPEG images and the RAW images act differently. The JPEG images are placed in a series of fixed image size buckets, while the RAW image sizes progress smoothly from full wide angle to full telephoto.




The process of having the JPEG images in image size buckets can be understood a little better with graphs of megapixel image size versus Hybrid Zoom focal length. First the 24-60mm lens.




Then the 70-300mm lens where it is a little more obvious.



For the JPEG images the camera processes the images into fixed reduced image size buckets until the image would be too large to fit that bucket size and then it steps to the next smaller bucket size. And there only two image size buckets smaller than the original image size.

RAW is a different story. The image size is the same as the Hybrid Zoom crop size, and it varies smoothly throughout the zoom range. In every case the image size is greater with RAW than with JPEG except at the points where the JPEG image size would equal the RAW image size.

There are many advantages for RAW images when using Hybrid Zoom. The zoomed image can be the starting point if you want to change the zoom position or shape or size. RAW with Hybrid Zoom can be useful to frame and focus in on part of an image where you will later expand the crop size. And using RAW with Hybrid Zoom assures you will always have the maximum image size for any zoom setting.

While I've used the S1R II camera here, the same principles obviously apply to all Lumix S series camera that have Hybrid Zoom. Also I've not discussed Crop Zoom(Photo), but it functions basically the same with RAW as Hybrid Zoom(Photo), and is useful with non-zoom lenses.

 

[Jan.Wedekind]

I have turned this on but on the smallest setting (I think) so I don’t “over crop” and never turn it off. Even fully zoomed in I basically am left with the same resolution as on the S1. For framing alone it’s useful. For friends and family I often just take the JPG directly

 

[pdk42]

That’s interesting Charles, but unless I’m misunderstanding, it looks like hybrid zoom is actually quite unhelpful for stills shooters if the objective is to maximise the “reach” of a zoom lens. What I mean by that is that if want get, say, a 85mm equiv crop out of the 24-60 on the S1Rii, then the obvious thing to do would be to set the lens at 60mm and crop by about 1.4x, giving me a little under 24Mp of resolution left. But using hybrid zoom, it looks like when it tells me it’s at 85mm, the lens is actually at 51mm and the crop would result in an image of only about 16Mp. What’s the point in that? And of course for any focal length greater than 24Mp but less than 60Mp, it’s cropping when there’s no need at all. Maybe it makes sense for video to give a smooth zoom from 24-120 effective, but for photography it’s quite counter intuitive.

Am I missing something?

 

[CharlesH]

What I mean by that is that if want get, say, a 85mm equiv crop out of the 24-60 on the S1Rii, then the obvious thing to do would be to set the lens at 60mm and crop by about 1.4x, giving me a little under 24Mp of resolution left.

That is exactly what you get with Hybrid Zoom if you set Minimum Image Zize to "M". This is a logical way to use Hybrid Zoom, and I believe this is what @Jan.Wedekind is suggesting in his post above.

 

[GeorgeHudetz]

I've been struggling with this a bit too.

Charles, are you saying that the raw files are actually cropped? I would have expected the raw files to always be 44 MP.

I suppose that even if the raw files are cropped, they are always larger than the JPEG (except at the extreme ends) so it doesn't matter too much, unless one likes the ability to discover other comps in the raw file, in which case I'd always want the entire file.

If indeed the raw files are cropped, then they would be smaller on the card/disc, which is always nice. And I have to ask again: would this reduce the cache-clearing time. I'll take a look tomorrow.

 

[CharlesH]

Charles, are you saying that the raw files are actually cropped? I would have expected the raw files to always be 44 MP.

The RAW files are NOT cropped, they are always 44 MP. And the crop region information from Hybrid Zoom is embedded in the RAW file EXIF data. And Lightroom can show the crop region.

See my first Lightroom example of the Develop page above, with the Crop and Straighten tool selected. Note the full 44 MP RAW image is there, and the crop region from the EXIF data is highlighted. If you want to use the entire 44 MP image you just fully expand the crop region manually - you un-crop it. Or you can modify the crop region however you want; bigger, smaller, move it around. When you close the Crop and Straighten tool you see whatever is in the cropped region - up to 44 MP if you fully expanded the crop region.

To be clear, for RAW this is no different than normal Crop and Straighten in Lightroom. Hybrid Zoom just gives you a crop starting point that equals the effective focal length you selected for the picture. I realize this can be somewhat difficult to explain clearly, and let me know any questions.

By background, with my Sony A1 I set a button so I could toggle between full frame and APS-C imaging. This was useful for extending a telephoto lens by 1.5x. Lots of Sony photographers use this. But this was fixed, either full frame or APS-C. The Panasonic method is much much better. You use the lens zoom ring to set whatever crop you want. And on top of that you can modify the crop however you want in post-processing. I may seem like an evangelist, but it's because I'm coming from a much less powerful Sony approach.

 

[pdk42]

That is exactly what you get with Hybrid Zoom if you set Minimum Image Zize to "M". This is a logical way to use Hybrid Zoom, and I believe this is what @Jan.Wedekind is suggesting in his post above.

I guess I’ll have to read the manual! I’ve put hybrid zoom into the “video or jpeg feature” box and therefore of no interest to me!

 

[pdk42]

BTW, this passing of crop info in raw files into LR also happens if you choose a different aspect ratio at shooting time (65:24, 1:1 etc).

 

[GeorgeHudetz]

The RAW files are NOT cropped, they are always 44 MP. And the crop region information from Hybrid Zoom is embedded in the RAW file EXIF data. And Lightroom can show the crop region.

See my first Lightroom example of the Develop page above, with the Crop and Straighten tool selected. Note the full 44 MP RAW image is there, and the crop region from the EXIF data is highlighted. If you want to use the entire 44 MP image you just fully expand the crop region manually - you un-crop it. Or you can modify the crop region however you want; bigger, smaller, move it around. When you close the Crop and Straighten tool you see whatever is in the cropped region - up to 44 MP if you fully expanded the crop region.

To be clear, for RAW this is no different than normal Crop and Straighten in Lightroom. Hybrid Zoom just gives you a crop starting point that equals the effective focal length you selected for the picture. I realize this can be somewhat difficult to explain clearly, and let me know any questions.

Overall I do understand, and I do like how LR handles the hybrid zoom & aspect ratio set by the camera.

The only thing I don't understand is why you have a "Raw MP" column in your tables. Shouldn't that always be 44 MP? What is it that you are trying to communicate here?

By background, with my Sony A1 I set a button so I could toggle between full frame and APS-C imaging. This was useful for extending a telephoto lens by 1.5x. Lots of Sony photographers use this. But this was fixed, either full frame or APS-C. The Panasonic method is much much better. You use the lens zoom ring to set whatever crop you want. And on top of that you can modify the crop however you want in post-processing. I may seem like an evangelist, but it's because I'm coming from a much less powerful Sony approach.

Don't get me wrong - I think it's great that you took the time to start this thread. It really does explain clearly what is going on with regard to the zoom's focal setting and what gets recorded in the JPEG.

However, overall, I'm with Paul on the "not for raw shooters" comment. When I frame a shot at 60mm on my 20-60, I want the raw file to record a full 60mm shot - not a 43mm shot. Which is to say, I want all the pixels to be deployed at an actual 60mm focal length. Of course, once I go beyond what the lens can accomplish, it's great to have compositional aids. I wish there was a way the zoom ring could keep on going - digitally speaking - after it hits it's mechanical stop. But of course no lens (currently) does that so the hybrid zoom feature has to work with how the lenses function. Does the new functionality which allows us to assign functions to the focus ring allow this? That would be cool - use the mechanical zoom ring to maximize the optical zoom, and then use the stopless focus ring to digitally zoom.

But it's a great feature for JPEG shooters, for sure. I agree it's much better than a simple toggle to a fixed crop value.