# Canon MF4890dw produces tilted lines when scan from ADF



## aceOfWands (Nov 14, 2014)

I bought a new Canon imageClass MF4890dw multifunction unit about a year ago.

I am mostly pleased with it, altho it is a typical Japanese product: good hardware marred by mediocre software and user interface.

One of the prime reasons that I bought this model is that comes with an ADF (auto document feeder) that can be used to automatically scan double sided documents. In theory, this is an amazing capability when you need to scan a bunch of pages.

Unfortunately, I have found that whenever I scan a page using the ADF, that lines of text appear to tilt down to the right.

This defect is limited to the ADF--if I scan a single page by putting it on the platen glass, there is no such tilting.

My guess is that this tilting is produced by the fact that the paper is being continuously moved thru the machine as the scanning head travels the width of the page. If this horizontal traversal was fast enough, the tilting would be minimized, but in reality, it is not.

Does anyone know what really causes this tilting?

Is there any way to fix it (e.g. some scanner setting that I overlooked)?

If my theory above is correct, then a smart scanner could correct for it by doing an image correction calculation.

At work, our high end Brother MFC does scans that have no such tilting, so I know that good scans are possible in practice.


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## Mt Spokane Photography (Nov 14, 2014)

Paper is skewing as it goes thru the feeder, a common issue. The better scanners have skew detectors, etc. But they also start at $1000.

Best to return it or exchange it, something is likely out of kilter.

Fujitsu makes the best ADF, IMHO, but their good ones are pricey.

For photo work, don't use a ADF.


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