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Does Anamorphic 1.33 Lens Result in LOSS of Resolution and Blocky Images
I have been having some trouble with image quality (blockyness) using a 1.33x anamorphic lens. It happens to be concerning still images shot on my iPhone using the Moondog Labs anamorphic lens (I assume the same issue would apply to filming video with it) but I wonder if it has something to do with this:
1) When using the Moondog Labs lens the resulting still image is 4032×3024 resolution which comes out to a 12MP image. That’s fine – the iPhone 7 Plus back facing lens is also 12MP so it’s what you would expect
BUT
2) When you “desqueeze” the width of the still image by 1.33 times so it looks correct – then the math comes out to a 5363×3024 meaning it’s now a 16MB image – so are the extra pixels being “made up” by Photoshop OR were the extra pixels inside the original image all along and it’s just that now you can see them in their proper aspect ratio – desqueezed?
3) In the workflow I have been using, I take the desqueezed image and scale it down – back to a 9MP image – assuming that my Step 2 is indeed creating extra pixels that weren’t originally captured – do you think this scaling back down would do anything to, so to speak, recover the original image quality?
Steve Crow
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7 Replies
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When you “desqueeze” the image, the machine takes the original readout and stretches the pixels horizontally. This obviously gets mapped to the pixels on your monitor, but that’s how the computer “thinks” about it. A similar thing used to happen with HDV footage: it was actually 1440×1080, and would be desqueezed in post to get the equivalent of 1920×1080. There shouldn’t be an appreciable quality loss, not at 1.33x.
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Thanks for your response on this – I’m doing some experiments now in Photoshop to dive into this further – you may be right. Although the camera lens and image sensor is so small that I wonder if even a small stretch might have quality impact
Steve Crow
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anything done anamorphic automatically means a loss of quality. squeezing and desqueezing even 6k or film equivalent leads to a softness. now, in a phone with a sub 100K lens, who knows what chromatic aberation, distortion, softness gets introduced. one could argue you can matte it out later if you don’t care about those lens flares, but i’ve also noticed that some authentic looks actually come from an imperfect inverted barrel distortion.(subtle)
also, I have even recommended that people grade their Go-pro images before removing the lens distortion as that actually causes banding if done before grading. so your issue with a small sensor may be very much related.
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Hi Chris,
Yes, I shot an image of a horse recently with my iPhone 7 plus in the native camera app with the Moondog Labs anamorphic lens attached to the “wide” lens. The camera shoots a 4K still image (4032 x 3024), roughly equivalent to a 28mm according to apple. When I look at the hair of the horse at 100% magnification I do see lots of blockyness (however you spell that) And that could be down simply to the camera being unable to resolve such fine detail and maybe causing a moire type of effect.
I’m creating some new procedures for myself as I work towards my goal of creating a cinemascope 2.36:1 still image which is pretty heavily color graded.
BTW, I know this isn’t the right forum for still images but if I wanted to post my images online – do you know of a site that would accept an image that it is Cinemascope wide? Instagram wants to crop it to square which defeats my purpose. I was thinking maybe 500px but I haven’t done much real research into it yet
SteveSteve Crow
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if you want to share it to people with a 4:3 screen, why not just black matte the sides to square?
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Oh, because the whole point of my little project is to create widescreen still images (cinemascope aspect ratio) as if the still image might be a single frame taken from a movie. I’m putting a white border all around the image to almost look like that frame from the “movie” has been matted like a traditional photograph and framed you might say.
My iPhone 7 plus has a screen resolution of 1920-by-1080-pixel resolution (16:9) at 401 ppi and I’m working with images in a totally different aspect ratio and resolution so it’s never going to be straightforward but that’s just part of the “fun” of this project to see how can I work around/with these challenges. If it were easy, everybody would be doing it right? haha
Steve Crow
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I’m not really concerned with 4:3 screens – I’ve decided to post my images on 500px
Steve Crow
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