Reflecta ProScan 7200 - Vertical Banding Issue

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SanTheMan
Beiträge: 1
Registriert: Dienstag 15. Oktober 2013, 11:01

Re: Reflecta ProScan 7200 - Vertical Banding Issue

Beitrag von SanTheMan »

Greetings from Spain.

I got to this thread researching about the annoying banding with my Reflecta Proscan 7200. I got the scanner a month ago, but I didn't notice until I got three complete rolls scanned. In my case it was specially noticeable in the infrared channel, with vertical grey bands, but I thought it was part of the negative damages due to mechanical processing along with dust and scratches. Later I realized they formed a persistent pattern and it was hardware related... After noticing the issue I started doing all kind of trial and error checks and counter-checks and first I thought it had something to do with static electricity, but bands keep coming back randomly. Then I thought the culprit was my mobile phone, wich I use for tethering and usually place next to the pc and scanner, again to have the banding coming back and going away on random basis. Now thanks to you I realize that through all my checks I powered off and on the scanner some times and that did the "trick" that you already explained.

I would be lying if I said I'm not heavily dissappointed with the situation, but at least now I know how to tackle the banding. I think the Reflecta is a very capable device and I'm pretty happy with the scans it delivers, so this is even sadder because it flaws a very nice purchase and user experience. Maybe Reflecta (or Pacific Image) should do something about this with a firmware update so the scanner recalibrates itself properly when needed.

Again, thanks.
Stefanh61440
Beiträge: 52
Registriert: Sonntag 7. April 2013, 16:10

Re: Reflecta ProScan 7200 - Vertical Banding Issue

Beitrag von Stefanh61440 »

Hello,

I don't have a ProScan 7200 but a DD5000 but maybe I can contribute something to this issue.
During the scan of a large amount of pictures I recognized a grey vertical banding starting randomly but affecting more and more scans after some time. Finally I talked to reflecta personnel and they recommended to replace a certain type of cable (a white flat multicore cable). I wanted to replcae it myself and so I tried loosening the ends of the flat cable and fixing it back again afterwards. Before I ordered the new cable from refelcta I verified that I did not add any further damage and to my surprise the banding was completely gone and never returned since.

My suggestion to you: If the warranty of your ProScan 7200 has expired, open it and remove and re-connect all the cables.

I cannot guarantee that it will work, but it did for me.

regards,
Stefan
D.Page
Beiträge: 11
Registriert: Mittwoch 12. Juni 2013, 11:03

Re: Reflecta ProScan 7200 - Vertical Banding Issue

Beitrag von D.Page »

Hi All.

I’m so sorry, I never realised that there have been posts, many that are valuable and informative, since I last contributed to this thread. I thought I had set it so that I’d get email alerts whenever a new post appears on this thread, but obviously not! I will add a post soon (after Christmas), to comment about where I currently am, with regards to the Proscan 7200.
D.Page
Beiträge: 11
Registriert: Mittwoch 12. Juni 2013, 11:03

Re: Reflecta ProScan 7200 - Vertical Banding Issue

Beitrag von D.Page »

Hi All.

I can, obviously, only comment on my own experience with the Proscan 7200. I did have an initial problem with random-type vertical banding (which sometimes appeared and sometimes did not, and was not consistently in the same locations in my scans when it did appear), but this issue seemed to clear up as soon as I updated to the latest drivers and firmware (as Silverfast advised me to do, after I contacted them about this particular banding issue). This random-type vertical banding is not to be confused with the vertical banding issue I now go on to comment about.

The vertical banding, which has been the cause of such persistent problems for me, is always located in the same places on each scan, every time. I have gone through - and returned - five different Proscan 7200’s, now. They all produced this vertical banding to some degree, most noticeable over plain areas of (particularly denser) scans. As I’ve previously stated in an earlier post, this banding is subtle, and others who encounter it may conclude to themselves that they can live with it, but this phenomenon is not altogether acceptable to a serious amateur photographer, especially one with perfectionist tendencies, like myself. I initially thought that the likeliest cause was the calibration strip not being 100% pristinely clean, but I would have thought this to be an unlikely cause, given that I've tested five ProScan 7200's, some of which were from different batches. Let me also point out that two of my Proscan 7200's also had an additional problem of dead pixels in the scanner head, causing one-pixel wide vertical lines to appear in my scans, at precisely the same locations in every scan, when viewed at 100% magnification (lines which did not deviate whatsoever to the left or right all the way down my scans). You could certainly make out these lines when printing at A4 size.

Each machine seemed to produce the banding at different locations in the scans, when comparing scans from machine to machine, and some machines were marginally worse, some were marginally better, but none of them were what I would call “within acceptable tolerance” for my own purposes. I have been without the Proscan 7200 for a few months now. I may decide to try another, as I do very much like the machine in all other regards but, like others have commented, I feel this banding is a limitation of this particular scanner and I expect that they will all produce the banding - to some degree. Question is – can I hope to acquire one which is has the banding to what I would call an “acceptable” degree? I want to be able to print scans to around A4 size. Ideally, I would obviously want any banding to be invisible altogether at A4 size, but at worst, I may be able to live with the issue, if the banding is extremely hard to spot over plain areas of images.

I have looked at competing scanners within the same price bracket (via the reviews on the ScanDig website), but do not wish to have to scan at very high resolutions in order to (eventually) capture all the detail I require, which takes more time, and then have to carry out further additional procedures in Photoshop, in order to reduce bloated file sizes. The Proscan 7200 is the only scanner in my price bracket which produces scans at a resolution that is acceptable to me, but without the complicated workflows of the other competing scanners in this price bracket.
Zuletzt geändert von D.Page am Dienstag 31. Dezember 2013, 14:47, insgesamt 4-mal geändert.
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Jossie
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Registriert: Sonntag 10. Februar 2013, 19:40
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Re: Reflecta ProScan 7200 - Vertical Banding Issue

Beitrag von Jossie »

Hi,

if the banding is always at the same place, this is most likely a flatfield problem, as stated earlier in this thread. I miss in your contribution a comment on the trick with turning the scanner off and on after some warming up time. Have you tried that?

The other issue is the resolution. You mention, that you need the high resolution (meaning that you have fine-grained film material?) and do not want to bother binning down to a managable file size. To my experience with my DD6000 the measured resolution can vary widely from scanner individuum to scanner individuum (my first one reached just 2000dpi instead of the 5000dpi advertised). So this would be another issue I would worry about. Have you measured the resolution of each scanner you got or at least compared their resolution relatively?

You mention printing the scans on A4-sized paper. This would mean that using a printer with 300dpi you will need 3500 independent pixels along the long side. Converting this to a slide size of 36mm, you need to scan at a real resolution of 2500dpi. If the ProScan7200 has, as the ScanDig test shows, indeed almost 3600dpi, this would be more than adequate for this printing purpose. Other printer resolutions scale accordingly, of course.

Hermann-Josef
DigitDia6000 (CyberView, SilverFast Archive Suite 8 & 9) / CanoScan9950F (ScanGear, VueScan Pro), Eizo CS240, xrite i1studio, Win11 (64bit), Intel i9 (3.4GHz), Speicher 64GB, Nvidia Quadro P2000
D.Page
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Registriert: Mittwoch 12. Juni 2013, 11:03

Re: Reflecta ProScan 7200 - Vertical Banding Issue

Beitrag von D.Page »

Hi Jossie.

As I say, I'm not in possession of the Proscan 7200 at the moment, but when I was in the process of testing out the five Proscan 7200's I had, I would frequently turn the scanner off and on throughout the (usually) several hours of testing each day. It did not seem to have any affect on the (consistently located) banding issue (for me). I remember that turning off and on did seem to (temporarily) cause the random-type banding to cease - that is, until the driver/firmware updates seemed to permanently clear this problem up for me. Let me point out that the consistently located banding issue was always quite subtle in its severity, compared to the random-type banding issue, which was always more severe, and prominent, in the affected scans.

I don't quite understand your point about ScanDig's report on the Proscan 7200's resolution: Its review states that this scanner reaches around 90% of its quoted maximum resolution, in practice (around 3250ppi in practice, rather than its quoted 3600ppi). Where did you read that it reaches only 50% of its nominal resolution? 3250ppi equates to around 14MP equivalent - more than adequate for my purposes.
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Jossie
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Re: Reflecta ProScan 7200 - Vertical Banding Issue

Beitrag von Jossie »

Hi,

sorry, I mixed up your scanner with another one, but soon after, I corrected my contribution. So you must have read it during the half-hour, there was still the uncorrected version online :oops: . I also added the calculation of the required resolution, if you print on A4-paper.

For this consistent vertical banding I saw no other physical explanation than the CCD's flatfielding properties. If, however, as you point out, all ProScan7200 suffer from this, there might also be an electronical problem involved. Did you contact PIE directly concerning this issue (reflecta ProScan7200 seems to be their PrimeFilm7200)? They have been quite helpful upon my inquiries in the recent past. You better try their US-support, not their Taiwan web page.

Best wishes

Hermann-Josef
DigitDia6000 (CyberView, SilverFast Archive Suite 8 & 9) / CanoScan9950F (ScanGear, VueScan Pro), Eizo CS240, xrite i1studio, Win11 (64bit), Intel i9 (3.4GHz), Speicher 64GB, Nvidia Quadro P2000
D.Page
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Registriert: Mittwoch 12. Juni 2013, 11:03

Re: Reflecta ProScan 7200 - Vertical Banding Issue

Beitrag von D.Page »

Hi Jossie.

Yes, this is one of the areas that I consider to be very impressive about the ProScan 7200, the fact that it achieves, in practice, most of the resolution that Reflecta quotes the scanner is capable of, which is not altogether common, if you read other scanner reviews on ScanDig’s website!

I don’t pretend to be anything other than a relative newbie to the whole area of film scanning, and, no, I didn’t compare the resolutions of scans from machine to machine, with any kind of resolution reference chart which may be available, to accurately determine resolution. I do have many examples of scans from each of the five ProScan 7200’s I was in possession of, and will always keep them for reference. If you expect there to be, possibly, wild variation in achieved resolution from one ProScan 7200 to the next, I suppose I am unable to accurately determine this now, simply by closely examining the scans made, in Photoshop and at high magnification, from machine to machine? I did do a scan, with each of the five machines, of a blank negative (from the leader of one of my rolls of film), for the purpose of examining it in Photoshop, where you can clearly see the locations of each machine’s banding issue by playing about with each corresponding machine’s blank scan, which I have saved on the PC, using Curves, Levels etc.

Would you say it is quite possible for every ProScan 7200 which comes off the production line to suffer this issue as a result of your theory of it being caused by a flatfield problem? Would you be kind enough to elaborate on what ‘flatfield’ is, for me, or, alternatively, point me to articles about this online? I’d be very grateful.

My ProScan 7200 supplier, themselves, contacted Reflecta about the issue but I gather Reflecta was not really prepared to investigate the issue, being more content with telling my supplier to just repeatedly supply me with replacement machines. Like you say, it may be a good idea to try to contact PIE about the problem.
Zuletzt geändert von D.Page am Dienstag 31. Dezember 2013, 17:02, insgesamt 2-mal geändert.
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Jossie
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Re: Reflecta ProScan 7200 - Vertical Banding Issue

Beitrag von Jossie »

Hi,

no, I did not want to state that with the ProScan7200 there is also this variation in actual resolution. I just wanted to point out, that this is my experience with my DD6000.

Concerning the flatfield:
Each CCD is an individuum and each pixel of a given CCD has ist own sensitivity. So if you scan an homogeneously illuminated source with a CCD, the resulting raw image is not flat or homogeneous at all! Such an image is called a flatfield image. This describes the sensitivity variations from pixel to pixel. What one does is dividing every image by such a normalized flatfield, thus eliminating any sensitivity variations. Now, if a pixel's sensitivity is e.g. temperature dependent, the flatfield taken when you turn on the scanner (or initialize the software), may no longer be valid after the scanner has warmed up. This is why you might get vertical banding. Turning off the scanner will force a new flatfield be taken and the banding is gone. So far the theory. There is an entry in Wikipedia about flatfield correction http://en.wikipedia.org/wiki/Flat-field_correction, but it is not entirely correct, because it mixes into the flatfield also optical effects like vignietting, which is of completely different origin. Admittedly, it is difficult to disentangle the different contributions in praxis.

Hermann-Josef
DigitDia6000 (CyberView, SilverFast Archive Suite 8 & 9) / CanoScan9950F (ScanGear, VueScan Pro), Eizo CS240, xrite i1studio, Win11 (64bit), Intel i9 (3.4GHz), Speicher 64GB, Nvidia Quadro P2000
D.Page
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Registriert: Mittwoch 12. Juni 2013, 11:03

Re: Reflecta ProScan 7200 - Vertical Banding Issue

Beitrag von D.Page »

Thank you, Jossie. Very interesting.

Let me quickly make the point that I used to own an Epson V700 film scanner. This machine also incorporated a flatbed document scanner. I had to return it because I could not get one which did not have small white particles of dust stuck to the underside of the glass platen. I only discovered the ScanDig website after I had returned the Epson, and probably wouldn't have bought it in the first place if I had known that it was only capable of around 2300ppi, in practice (according to ScanDig's review). One thing which was useful, however, is that I still have many scans made with the Epson and I have examined them closely and cannot detect any problem whatsoever with vertical banding. So, it confirms to me, that one should not expect to have to put up with such banding, even with scanners that have been manufactured for the domestic market, and are relatively inexpensive.
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Jossie
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Re: Reflecta ProScan 7200 - Vertical Banding Issue

Beitrag von Jossie »

Have you seen this thread: viewtopic.php?f=7&t=27294?

Sensitive tests for banding problems can be made either by skewing the histogram to bring out dark parts bright (this is how I detected a mis-behaving pixel and problems at both ends of the array in my previous scanner). Another possibility is to use imageJ and stack all image rows in an image with not much structure in it (like an unexposed dark slide from the end of a film spool) to increase the signal-to-noise-ratio and bring out fine deviations.

Hermann-Josef
DigitDia6000 (CyberView, SilverFast Archive Suite 8 & 9) / CanoScan9950F (ScanGear, VueScan Pro), Eizo CS240, xrite i1studio, Win11 (64bit), Intel i9 (3.4GHz), Speicher 64GB, Nvidia Quadro P2000
D.Page
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Registriert: Mittwoch 12. Juni 2013, 11:03

Re: Reflecta ProScan 7200 - Vertical Banding Issue

Beitrag von D.Page »

Thank you for the link, Jossie.

I cannot speak German, however(!). I will endeavour to get the info translated, and hope that I can get an accurate translation. Thanks.
D.Page
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Registriert: Mittwoch 12. Juni 2013, 11:03

Re: Reflecta ProScan 7200 - Vertical Banding Issue

Beitrag von D.Page »

Having been in conversation with Reflecta via email, they have disclosed to me that they are, indeed, aware that some ProScan 7200’s exhibit a banding problem. They told me that they will ‘re-engineer’ (as they put it) the ProScan 7200, presumably so that it eliminates (or at the very least, minimises) any banding issues.

However, rather than recalling the current stocks, the ProScan 7200 is available to buy right now, presumably with many of these units liable to exhibit the banding problem(?). Could it be possible that Reflecta’s strategy is to keep this banding problem hushed up, and continue to sell all the current stocks of this scanner, and then revert to selling stocks of ‘re-engineered’ or updated ProScan 7200’s – without anybody having any knowledge of when the stocks of the ProScan 7200 have changed over to the updated units?
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