Plustek 8100 pixelated scans

S

Stelios

Guest
Hi all,

I have been having scanning troubles with my Plustek scanner ever since I bought it a few months ago and I am giving up trying to troubleshoot it. My main aim is to get an image that will roughly match my D700 resolution (at 4256x2832 at 240dpi). I am generally setting my the scanner to a 30x40cm image at 240dpi which brings it to that resolution. However in some scans I get a strangely pixelated image. And I say strange because I don't get it in all of my scans and I cannot replicate the fault. I will include 3 images to show my example, with 100% crops to illustrate the "problem". From the 3 images only the first shows the pixel problem, while the other 2, even though they are on the same or similar resolution do not. I have tried looking for solutions but the Silverfast support isn't that great.

Example 1


100% crop


It's scanned to this resolution


Example 2 (resolution 4933x3301 at 3600dpi, go figure...)


100% crop


Example 3 (Resolution 4485x3021 at 240dpi)


100% crop




These are generally my settings when scanning.




I may be pixel-peeping (and slap me if I am) but I cannot understand why this is happening. Any clues, much appreciated.

Thanks,

Stelios
 
Scan at 3200 and most artifacts and grain will be gone. In Photoshop, resize (downsize) the image to the correct size with 240dpi and it will condense the scan resolution to a print resolution.
 
johannielscom said:
Scan at 3200 and most artifacts and grain will be gone. In Photoshop, resize (downsize) the image to the correct size with 240dpi and it will condense the scan resolution to a print resolution.
Click to expand...

Agreed. At 240dpi the scanner has to make all sorts of adjustments you don't want it to. I scan at 3600 dpi at actual size. Resize for print/web later.
 
Thank you both, much appreciated. Do you set the 3200dpi using the slider or using the Preset input box?

Stelios
 
A good general rule is to always scan at the maximum resolution possible, taking into account - file size / time needed for the scan / final output intention.

And then as mentioned above you want to downsize in photoshop. A high resolution scan will give you the maximum detail possible from the negative and allow the software enough to work with, avoiding the pixel effect you've seen.

For reference, screen resolution is 72dpi and print resolution is 300dpi.

If you have the storage capacity then scanning at higher resolutions will give you a big enough file for almost any use in future. It's always quicker to resize / downsize an image than it is to rescan in order to find more detail and resolution.

Hope there's something there that may help.
 
thereabouts said:
I always scan at 7200, for this reason.
Click to expand...

From the article:
I like to print fairly large – so I went for a model that could scan optically to 7200dpi.
Click to expand...

Which scanner can do 7200dpi optically? Not the Plustek 8100 IIRC, that maxes out at 3600dpi optically and the 7200 is just a software gimmick.

My Plustek 7400 has no ICE and if I want to reduce pixelated scans, the best setting is 3200 dpi. From there on, it's possible to go for 3600 dpi if the need arises.

If I want it scanned with optimal conditions it goes to the Imacon Photo, which also has 3200dpi max. And it improves on the Plustek's 3600dpi.

I say with the Plustek 8100, scanning at 7200dpi is useless in optical resolution and certainly in file size.
 
Thanks everyone.

I have been weary of going too high on the resolution as to not go over the optical resolution capabilities of the scanner. I think 3200dpi would be the maximum.

The Silverfast software is not particularly intuitive in terms of defining the resolution. I'll try 3200dpi at normal size and take it from there...There is no point going over that if it gives pixelated images, is it?

Thank everyone, I'll test again tonight and provide feedback. It certainly is a learning curve, as expected.

Cheers,

Stelios
 
johannielscom said:
From the article:

Which scanner can do 7200dpi optically? Not the Plustek 8100 IIRC, that maxes out at 3600dpi optically and the 7200 is just a software gimmick.

My Plustek 7400 has no ICE and if I want to reduce pixelated scans, the best setting is 3200 dpi. From there on, it's possible to go for 3600 dpi if the need arises.

If I want it scanned with optimal conditions it goes to the Imacon Photo, which also has 3200dpi max. And it improves on the Plustek's 3600dpi.

I say with the Plustek 8100, scanning at 7200dpi is useless in optical resolution and certainly in file size.
Click to expand...

Plustek do claim on their website that the 8100 optical resolution is 7200dpi. Not sure I believe that...Unless I'm reading it wrong.
 
I just had another go at scanning at 3600dpi (I believe that is the limit...) and there are no artefacts visible. That resolves it so thank you everyone.
On the other hand, the file is larger (both in size and resolution) than what I was trying to achieve by scanning at 240dpi and 30x40cm-ish which is bizarre to me, however if it works, it works. It's a shame that I control the output at 240dpi through the programme itself.
I should correct that Plustek claims the 8100's hardware resolution is 7200dpi and not optical resolution.
I hope this helps others too.

Cheers,

Stelios
 
I spoke too soon.

I have scanned several images at 100% (ie 36mmx24mm) at 3600dpi. Some come out good some with artefacts. Changing from 48bit HDR to 48bit->24bit sometimes works but not always. It's actually sometimes the 48bit HDR that works. Files with the same file size and resolution may or may not come out OK.

At this stage I think my machine (or software) might be the problem.

EDIT: I even scanned at 2400dpi and I get artefacts...
 
johannielscom said:
I say with the Plustek 8100, scanning at 7200dpi is useless in optical resolution and certainly in file size.
Click to expand...
It's true that the Plustek is nowhere near 7200dpi optically, however, the stepper motor is more precise when this option is selected in the software, which should lead to better resolution. It might very well be that in order to actually get the full 3200 or whatever dpi the scanner is capable off you'll have to scan at 7200dpi.
 
HDR? Why HDR? That's going to do multiple sampling, yes? Could be offset errors from each pass.

You can download Vuescan as a trial. It might give different results.

I assume that you are saving the file as a tiff or other non-compressed format.
 
Dan Daniel said:
HDR? Why HDR? That's going to do multiple sampling, yes? Could be offset errors from each pass.

You can download Vuescan as a trial. It might give different results.

I assume that you are saving the file as a tiff or other non-compressed format.
Click to expand...

No, HDR is simply a RAW scan in SF. It's single pass.
 
The Plustek 8100 does have an specified optical resolution of 7200. However, things aren't as simple as that. One also needs to take into account things such as 'measured resolution', which is the DPI which can actually be resolved by a scanner. The PDF from Plustek here talks more about this.

I also had an exchange with a Plustek technician and, because of this, he suggested scanning at 7200 and then reducing the size by 50%, for getting the maximum amount of information out of the scanner.

Your mileage may vary, of course.
 
As regards the pixelated scans. I had this with the Silverfast software a few times and, along with everything else that is horrible about that software, I dumped it in favour of VueScan.

That may not be very helpful for the OP, but it solved the issuess I was having.
 
Cheers everyone,

I have now emailed Plustek technical support and am waiting for their answer. Whatever the issue is it is not acceptable to get this banding at random scans. It may well be a Silverfast issue which I have not been fond of so far but that's what came bundled with the scanner. If I have to download Vuescan I won't be terribly happy. And yes I have been scanning TIFF files. If I want 2400dpi files for whatever reason, I should be able to get them. It's not beyond the scanner's capabilities.

If I can I may return the scanner if that is the case (I don't think Plustek will sponsor my Vuescan copy). If it's bundled with Silverfast, it should work with Silverfast.

Cheers,

Stelios
 
Final follow up on this issue.

I contacted Plustek via their website last night, received a response this morning advising me to download the latest Silverfast software and reset the settings. I didn't expect it to work but it did, and now the scanner seems like a different beast altogether. No strange noises and no strange banding effects. Even Silverfast seems a bit snappier and ever so slightly more intuitive. Happy camper! Mind you I haven't tried the utlra 7200dpi yet but I doubt I'll touch that.

Cheers,

Stelios
 
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