How does the Wolverine (1080p) scanner deal with 4:3 aspect ratios from Super 8 film?

[Brian Daniels]

I realize that the Wolverine does not zoom in on the Super 8 frame using AI before capturing each frame, and that, consequently, the frames need some form of image stabilization in post, but, assuming a perfect alignment of the frame to the machine, how does the scanner handle the 4:3 aspect ratio of Super 8 frames, given that the Wolverine uses a 1080p, or 16:9, aspect ratio?

Assuming perfect alignment, does the final output show black bars on both the left and right sides?

Does the Super 8 frame get cropped, removing the top and bottom of the frame, before zooming on the cropped area?

Or, does the Wolverine just take the whole Super 8 frame and just stretch it to fit the 16:9 aspect ratio of the machine?

[John Bakker]

1080 is the vertical resolution and it doesn't mean it's 1920 wide (16:9).
The Wolverine scans at 1440x1080 (4:3) and gives you the option of overscan (so you see the borders and parts of the previous and next frames) or scrop so you get s clean image without any borders.

[David Strelitz]

I know nothing about the Wolverine and similar but I do know a page or three about video resolution.
The crucial bit of info is the pixel aspect ratio aka PAR. Those pesky little blocks that make up the picture.1440*1080 with a 4*3 result means a PAR of 1:1 ie square pixels. This is indeed very unusual as most 1440*1080 video has a PAR of 1.333 (rectangular pixels) giving 16:9 and this was used on domestic/semi pro formats like HDV and broadcast PRO formats like Panasonic P2. I throw this into the mix as like all resolution numbers only tell part of the story.
In PAL land SD resolution is invariably 720*576 yet can be 4*3 or 16*9 depending on the PAR 1.067 or 1.42.
HD is way more simple on both sides of the pond 1920*1080 with beautiful square 1:1 pixels

[John Bakker]

Rectangular pixels are from the olden days when there was a need for compatibility between analogue and digital systems. This is about digital and proper HD in 4:3 aspect ratio is using the same vertical resolution as its 16:9 counterpart. This way it can be viewed with 1:1 pixel mapping on a 1920x1080 widescreen display.

[David Strelitz]

My point was that not all 1440*1080 was square in fact 1440 square is not the norm. P2 HD meets broadcast specs and not from the "olden days" uses 1.333 pixels.

[Nantawat Kittiwarakul]

We're only talking about Wolverine (and all of its clone) scanning resolution right? So here it is.
It's rebranded to Reflectra in this case but still strictly Wolverine inside.



So the correct/concrete answer is 1441*1080 square pixels. Therefore 4:3 aspect ratio.
By the way I had altered the playback speed from its default 20 fps to 18 fps hence the file extension changed from .mp4 to .avi, but everything else remains untouched.

[John Bakker]

My point was that not all 1440*1080 was square in fact 1440 square is not the norm. P2 HD meets broadcast specs and not from the "olden days" uses 1.333 pixels.

I stand corrected. Yes, non square pixels are still used in broadcast for compatibility reasons. But like you were saying, luckily consumers don't have to deal with all the different standards anymore.

[Brian Daniels]

We're only talking about Wolverine (and all of its clone) scanning resolution right? So here it is.
It's rebranded to Reflectra in this case but still strictly Wolverine inside.



So the correct/concrete answer is 1441*1080 square pixels. Therefore 4:3 aspect ratio.
By the way I had altered the playback speed from its default 20 fps to 18 fps hence the file extension changed from .mp4 to .avi, but everything else remains untouched.

Can't argue with the resulting video file where you can clearly see that the Wolverine created a 1441*1080 file. I guess in my case, I'll have to overscan to capture the whole frame for each of the frames on the reels I own.

[John Bakker]

I would always use overscan as it gives you more leeway in post processing. Stabilizing definitely needs extra. Be aware though that overscan doesn't scan at a higher resolution. You still get 1440x1080 pixels so after cropping you end up with a lower resolution than that which, if you want to maintain 1440x1080, has to be upscaled to that resolution. Ideally, a scanner would do overscan by using a slightly higher resolution so after cropping you're still left with 1440x1080 pixels.

[John Bakker]

Forgot to add
This is exactly what the Kodak Reels is capable of; it outputs a 1728x1296 image which you can crop to 1440x1080 in post so no loss in quality. Way better than the Wolverine.

[Stan Jelavic]

Talking about Wolverine and Wolverine clones resolution. Here are some results of the my setup that replaces the Wolverine camera with the equivalent camera.

The camera I use here is ELP web cam with the same AR0330 sensor and I reused the Wolverine 6mm lens.
My camera is mounted in the same location as the old camera so the optical setup is exactly the same as Wolverine.
Here is the uncropped image I get with the setup.


As you can see the image shows significant overscan. They had to do that in order to be able to grab both film formats.
Once the image is cropped you get only 800x600 resolution.
So where does the 1440x1080 resolution come from?
Very simple, they DOUBLE the image up digitally...
So I am not sure how Reels does it but considering that the mechanical dims are the same they will
have the same constraints and use the 6mm lens. It looks like they use IMX219 sensor with 1.12um pixel size.
Onsemi AR02330 has 2.2um size so with reels they would not have to image doubling. That could make
significant difference in quality although I like the AR0330 sensor. Larger pixel could give low light better
performance and the colors are awesome.
So, yes lots of tradeoffs to consider and the pixel rez is pretty low on my list.
BTW, cropping does not change the resolution i.e. the number of pixels per image detail does not change.

[John Bakker]

Nice work!
Yeah I was using the term resolution but meant image size in pixels.
The Reels has a sensor with 3280x2464 pixels but outputs 1728x1296 so no upscaling there, unlike the Wolverine.

[Stan Jelavic]

Thanks John,
Yes, Reels should have better image quality. Would be interesting to know if the MP4 compression is as heavy as in the Wolverine.

[Brian Daniels]

Talking about Wolverine and Wolverine clones resolution. Here are some results of the my setup that replaces the Wolverine camera with the equivalent camera.

The camera I use here is ELP web cam with the same AR0330 sensor and I reused the Wolverine 6mm lens.
My camera is mounted in the same location as the old camera so the optical setup is exactly the same as Wolverine.
Here is the uncropped image I get with the setup.


As you can see the image shows significant overscan. They had to do that in order to be able to grab both film formats.
Once the image is cropped you get only 800x600 resolution.
So where does the 1440x1080 resolution come from?
Very simple, they DOUBLE the image up digitally...
So I am not sure how Reels does it but considering that the mechanical dims are the same they will
have the same constraints and use the 6mm lens. It looks like they use IMX219 sensor with 1.12um pixel size.
Onsemi AR02330 has 2.2um size so with reels they would not have to image doubling. That could make
significant difference in quality although I like the AR0330 sensor. Larger pixel could give low light better
performance and the colors are awesome.
So, yes lots of tradeoffs to consider and the pixel rez is pretty low on my list.
BTW, cropping does not change the resolution i.e. the number of pixels per image detail does not change.

Stan, since you commented in my thread, I was going to ask you about another post you made a while back regarding the Wolverine MM Pro, since I'm not sure if you're last comment was in reference to evaluating the capabilities of the Wolverine scanner using a different camera, while keeping the same lens. It's the seventh post down.

For starters, what do you mean when you say that the optics of the Wolverine only gives you half the resolution that the Wolverine claims?

More specifically, when you talk about the optics of the Wolverine, are you saying that the Wolverine uses a low quality lens, and that, because it uses a low quality lens, that the machine is unable to resolve all of the detail, and that, consequently, that ends up, inevitably, impacting sharpness, regardless of what sensor was used, kind of like how a few years back, photographers would sometimes favor prime lenses, instead of zoom lenses, because prime lenses were, initially, generally always sharper?

Lastly, when you say that the Wolverine then doubles up the image digitally to get to 1080p, are you referring to a somewhat similar process known as digital zoom, as opposed to optical zoom, that's commonly used by many smartphones? Because if so, that's horrible.

[Stan Jelavic]

For starters, what do you mean when you say that the optics of the Wolverine only gives you half the resolution that the Wolverine claims?
.

The real optical resolution of the Wolverine MM is around 800x600 pixels. How do I know. I know because i used the same optics that the MM uses and the same sensor but different camera model where I can grab the individual frames and I get only 800x600 pixels for the S8 film. The MM camera produces the S8 images with 1440x1080 pixels so the only way I can explain this is that they resized the images. And yes it is like a digital zoom in a way. Pretty bad.
You can get more info on my project here:
https://github.com/vintagefilmography/WolverineFix
Regarding your lens quality comment.
The 6mm lens is actually a good quality lens based on my testing. But with the 6mm lens you cover only a smaller portion of the sensor. See my image in the previous comment. Replacing the lens with a 8 or 12mm lens would cover more sensor area and would give higher resolution. But they could not do that because the unit has to support both film formats, so some overscan is necessary and also that would require a larger spacing between the film and the sensor. That means possibly larger unit and a major redesign.

Image doubling question.
Yes, exactly that. Pixel interpolation...