Epson Perfection V850 Pro focus issue

[leodavut]

I have an Epson V850 Pro for home scanning of 35mm, 120 and some 5x4 negatives.

I've had no trouble, with good results for around a year until recently, when I've been having serious trouble getting sharp scans.

I've ruled out all other factors, rangefinder out of alignment, curly negs etc and the only remaining factor is the scanner itself.

I've also tried the neg holders at different heights and while the focus does change, I never achieve acceptable sharpness.

I guess I need some help/advice/fixes to this issue if anyone has also dealt with it..

Thank you!

And no, it's definitely not the cameras or focus!

 

[ChrisLivsey]

One further test you could run is scanning a document using the reflected light on the scanner bed. This would use the second lens and would show if that was out of whack as well. My suspicion is the alignment of the lens board has been disturbed, if the second lens is out as well then that looks a proof and will need factory service. If it is sharp it is still possible one lens is out I suppose but more unlikely.
Do you move the scanner regularly, locking the machine with the slider each time, or have you inadvertently forgotten and nudged it at some point perhaps, or never move it but it has been knocked in the unlocked state?

 

[leodavut]

One further test you could run is scanning a document using the reflected light on the scanner bed. This would use the second lens and would show if that was out of whack as well. My suspicion is the alignment of the lens board has been disturbed, if the second lens is out as well then that looks a proof and will need factory service. If it is sharp it is still possible one lens is out I suppose but more unlikely.
Do you move the scanner regularly, locking the machine with the slider each time, or have you inadvertently forgotten and nudged it at some point perhaps, or never move it but it has been knocked in the unlocked state?

I just scanned a document laid flat on the glass and it's absolutely pin sharp. what exactly does this mean?
thanks

 

[williaty]

In your scanning software, whatever you're using, are you sure you're selecting the transparency setting that uses the high quality optics (which focus several mm above the glass to allow use of the film holder) rather than the wide field transparency setting that shares optics with the reflective setting (and therefore has the plane of focus on the surface of the glass)?

If you're putting the film in the film carriers and then accidentally using the transparency setting for the wide field optics, you'd get soft results that you couldn't fix.

 

[ChrisLivsey]

I just scanned a document laid flat on the glass and it's absolutely pin sharp. what exactly does this mean?
thanks

It means that the system that holds the lenses is not out of mechanical alignment which would affect both lenses. It shows the scanner is working with that low res lens and that your problem is with the high resolution lens only.
(6400dpi for slides and film, and 4800dpi for flatbed) The lenses are focussed at different points, heights, it may be when the scanner should be selecting the high res lens it is not it is selecting the low res one and that the scan is therefore out of focus.
Although the lens selection is automatic and not user selected I have seen it reported that the high res only kicks in when that scan resolution 6400 is selected. I cannot believe that is the case because of the fixed focus focus planes.
It is not possible AFAIK, and I own one, to manually select the lens, it is done by the scanner automatically depending on the medium it sees as requiring scanning. That is independent of the resolution of the scan chosen in software. The presence of the holder for film or transparency tells the scanner to select high res, that is what I suspect is not happening, that is in firmware not software.
It means it needs a trip back for service, hopefully under warranty.

 

[xvvvz]

williaty makes a good point. The lens selection on these scanners is determined by whether you selected "film with film holder" or "film with film area guide" in the Epson software (I think those are the wordings) and something similar in Vuescan. The latter is used when scanning on/at the bed of the scanner and uses the second lens. There is a third choice for reflective but that isn't what you want to use for scanning film. For whatever reason, this software setting can get changed so confirming that setting is the last thing I check before initiating the scan.

Doug

 

[williaty]

The settings in Silverfast are "Wide Transparency" for the low-res optics with focus plane on the glass and "Transparency" for the high-res optics with the focus plane above the glass (for use with film holders).

 

[BLKRCAT]

If the 850 is anything like the 700 it uses a different focus point when scanning reflected vs when scanning film in the holder.

I ended up shimming my V700 holder with masking tape.

Setting the holder at the highest setting, then adding single pieces of masking or painters tape to the bottom of the pads to set it even higher. Focus point on my V700 was actually a little higher than the highest setting. Might be worth recalibrating before throwing in the towel.

 

[rjschell]

I too am using the V700. I found that a sheet of glass (approx. 2mm) on top of the scanner platen and the film holder pads set in the + position nailed focus for me.