What are these dots?

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Eldipro

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Hi everyone, happy to have joined the forum.

Started scanning with a used plustek 7200 that I've recently bought on ebay, using vuescan as software. I don't understand if these dots are just film gran or some sort of bad scanning. Any way to solve this issue? Or is it normal? Thanks!! Posting a zoomed-in section of a recent scan.
 

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koraks

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Welcome to Photrio, @Eldipro!

It's hard to tell from your image, but if I were to hazard a guess, you may be trying to scan a very thin (underexposed and/or underdeveloped) negative and then boosting the contrast to usable levels. In the process, a phenomenon called 'posterization' results, which is basically the entire tonal scale consisting of insufficient distinct tones to render a smooth scale. These distinct 'steps' of grey are the result.

To prevent this, try:
* Scanning at 16 bit depth if your scanner supports it
* Set the levels or contrast curve in the scanning software so that it captures the dynamic range of the negative, but not (much) more than that
* Ensure that exposure and development yield a usable negative in the first place

Can we see a photograph of the actual negative for reference? And it might also be useful to post what settings in VueScan you use (perhaps a screenshot of your scan settings?)
 

Les Sarile

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Welcome aboard!

Aside from the thorough analysis above, there is also a scanning anomaly called grain aliasing that can be introduced by the scanner and/or software combination that exacerbates the appearance of grain. This maybe such a case.

If it's not pleasing to you, you can address it in post using grain reduction software.
 
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Eldipro

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Thank you so much! I will take a picture of the actual settings when I get back home. I surely left the bit settings on "automatic" the last time I tried and didn't play much with them at all. This is the whole picture for reference (35mm ilford FP4 125).

1687973950095.png
 
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Eldipro

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Welcome to Photrio, @Eldipro!

It's hard to tell from your image, but if I were to hazard a guess, you may be trying to scan a very thin (underexposed and/or underdeveloped) negative and then boosting the contrast to usable levels. In the process, a phenomenon called 'posterization' results, which is basically the entire tonal scale consisting of insufficient distinct tones to render a smooth scale. These distinct 'steps' of grey are the result.

To prevent this, try:
* Scanning at 16 bit depth if your scanner supports it
* Set the levels or contrast curve in the scanning software so that it captures the dynamic range of the negative, but not (much) more than that
* Ensure that exposure and development yield a usable negative in the first place

Can we see a photograph of the actual negative for reference? And it might also be useful to post what settings in VueScan you use (perhaps a screenshot of your scan settings?)

Here are my settings for now..
 

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koraks

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Thanks for posting that! I don't see anything in terms of settings that would be very problematic, although if you scan to a JPEG file, the output will always be limited to 8 bit. If you then do a strong contrast adjustment afterwards, you can run into posterization problems.

Is it possible to post a photograph of the actual negative? This is to determine if it's in a normal range where the scanner will be able to give a clean output. The full image scan is nice, but it doesn't give much information if there might be a problem with the negative. I do see strong posterization in the full image as well; it's most apparent in the white shirt - but it's really everywhere if you look for it.
 
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Eldipro

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Thanks for posting that! I don't see anything in terms of settings that would be very problematic, although if you scan to a JPEG file, the output will always be limited to 8 bit. If you then do a strong contrast adjustment afterwards, you can run into posterization problems.

Is it possible to post a photograph of the actual negative? This is to determine if it's in a normal range where the scanner will be able to give a clean output. The full image scan is nice, but it doesn't give much information if there might be a problem with the negative. I do see strong posterization in the full image as well; it's most apparent in the white shirt - but it's really everywhere if you look for it.

Thanks to you mate. What do you mean by a picture of the actual negative? A scan of the negative as is, or a simple picture to the film with my phone? Also, what format would you recommend? Should I do negative raws and use Photoshop later?
 

kozesluk

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make sure you scan from 16 bit per pixel (it is set to Automatic according to the screenshot you sent).
 

koraks

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a simple picture to the film with my phone?

That one :smile: Preferably photographed with the negative held against a diffuse light. Your monitor with a white page in Word etc. usually does fine to get a quick impression of the negative.

Also, what format would you recommend?
I usually post from my computer, where I can just make a screenshot and copy-paste it into a reply. I never tried posting a photo on this forum from my phone to be honest; I think it should be pretty easy. Just snap a pic with your phone, and tap the camera icon at the top of the reply box. I imagine it's self-explanatory from there.
1687989864599.png
 
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Eldipro

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That one :smile: Preferably photographed with the negative held against a diffuse light. Your monitor with a white page in Word etc. usually does fine to get a quick impression of the negative.


I usually post from my computer, where I can just make a screenshot and copy-paste it into a reply. I never tried posting a photo on this forum from my phone to be honest; I think it should be pretty easy. Just snap a pic with your phone, and tap the camera icon at the top of the reply box. I imagine it's self-explanatory from there.
View attachment 342486

I get it ahah. I meant, in which format should I scan the pictures to not lose quality? Raw scanning does not invert the negatives,right?
 

koraks

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No, no scan. Just a snapshot using your camera phone. Indeed, it won't be inverted, contrast will be weird etc, but that's fine. I'd just like to be able to see the bare film the way you see it when you hold it in your hand.
 

MattKing

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I get it ahah. I meant, in which format should I scan the pictures to not lose quality? Raw scanning does not invert the negatives,right?

Scanning, no matter what format you use, doesn't give us the information we need.
Ideally we would be in the same room as you and be able to look at the negatives themselves - preferably with a diffused backlight behind them.
But as we can't do that, we ask that you take a digital photograph of the strip of film that shows us at least a couple of frames, the edges of the film including the frame numbers, and the space between the frames. The film should be as flat as practical, and parallel with the camera/phone's sensor - i.e. rectangular film should look rectangular
For purposes of uploading that here, a relatively small jpeg with a fair bit of compression works best - 80% Quality on the software I use. The goal is to be able to see the results clearly on our screens, which requires a well lit and focused image of the negatives themselves (not the subject you were photographing), but doesn't require a very big digital file. If you email the pic to yourself, try but small and medium file size and use the largest that works with our uploader.
Here to give you an idea of what I'm talking about is some 70+ year old film, complete with light leaks and all the stuff that can happen to film that has been sitting rolled up longer than I have been alive!
1688235425746.png
 
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