Too much noise in my scans

[peter_haagerup]

<p>I have scanned a lot of negatives and slides (all 35mm) with my Canon 8400F using SilverFast SE Plus.<br>

I have tried a lot of different scanning options to get rid of noise - especially multi-sampling and multi-exposure.<br>

The noise problems are very visible on negative scans. Mostly in lighter areas. If the negative is very dark (overexposure) I get VERY noisy pictures - looks very grainy with "incomplete" colors. In scans of positives, I sometimes have problems with noise in the darker areas - underexposures get very noisy, but not as bad as the overexposured negatives.<br>

I think the negative scans really looks like a digital picture converted to a low contrast picture and back to a normal contrast picture. That gives a whole lot of distortion.<br>

Even if I use 16x multi-exposure, I still have noise problems for some of the "hard to scan" photos - the prints made at the time of processing is just fine. No grain, no noise. Another problem with 16x multi-exposure is the long waiting time and sometimes softer image because of scanner vibration/bad alignment.<br>

Do I need a new scanner or will it just be slightly better?<br>

I want better quality than the prints.<br>

Most of the pictures are from Kodak Gold 200 film. Cheap, standard film - but I suppose the quality of the film is a LOT better than the 8400F can give me. The prints does not look grainy or noisy at all.<br>

I would like to be able to scan as many frames in a batch as possible. With 8400F, 12 frames is max. 11 for me, because there is a scratch on the glass surface.<br>

The Epson V700 (or V750) will let me do a batch scan of 24 frames - that's really interesting if the quality is a BIG step up from Canon 8400F?</p>

<p> </p>

[bob_himmelright]

<p>post a sample so people can see exactly what the problem is.</p>

[peter_haagerup]

<p>OK - here is a 100% crop at 6400 dpi. Actually, i think it is 3200 x 6400 dpi, interpolated to 6400 x 6400 dpi - still looks better than 3200 dpi.</p><div></div>

[andylynn]

<p>Here's the thing. A flatbed may say "6400 DPI" but it doesn't really pull down that much data, it scans at somewhere between 1600 and 2000 DPI and interpolates. This scan appears to have some cleanup applied as well by the scanner software (grain reduction plus sharpening maybe) and the grain you see at 100% is actually an artifact of the original grain (which is probably not this pronounced) plus whatever noise the scanner made (noise isn't just for DSLR sensors) after all that processing.</p>

<p>Since you don't have 6400 DPI of real data, that image size is just eating hard drive. What does it look like if you scan at 2,400 DPI with minimal grain/sharpness processing? Using that as a baseline, experiment until you find settings you like, but don't be expecting miracles - this is a flatbed scanner, not a film scanner, and you're not going to see the same results at 100% that the guys using Nikon LS5000's get.</p>

<p>The reason your prints don't look grainy is that the shop that made your prints used a better scanner, and their software is configured with film profiles and auto settings optimized to give the image that will look best on their printer. Since they're running at 4x6 at 300 DPI, they only needed a 1200x1800 file, which is a bit ove 1200 DPI fom the scanner, which is really easy to accomplish when your software is automated for that. But even with the scans you've got, if you printed at 4x6 you would see little or no grain.</p>

[janne_moren]

<p>Make that, no grain reduction nor any sharpness applied. Scanner software sharpening is typically set so that the image will look crisp when printed straight from the file - which means it's horribly oversharpened for anything else. Just turn it all off, scan at the base real resolution of your scanner (probaly around 2400dpi), then do sharpening and other things in postprocessing. Also, even at base resolution a flatbed will typically not give you a completely sharp image at 100% (the individual ccd elements don't focus really well). If that's important to you for some reason, you can downscale the image further (say, to 70% linear size) to make it look good at full zoom, and save disk space.</p>

 

[peter_haagerup]

<p>Thank you so much for your replies. I will try to give some more information:<br>

The optical resolution of the scanner is 3200 dpi. Mechanical resolution of 6400 dpi. I still think the images are soft at 100% both 3200 dpi and 6400 dpi. The problem for me is not the resolution. It is still better than the prints and that's good enough for me.<br>

The problem is, that many of the scans (48 bit negative) is very dark with 80% of the histogram being totally without data. Sure, it is a color negative scan, the original negative is low contrast. Only 20% of the scan is usable for generating a digital positive image with normal contrast. That's not enough - and flat colors and a lot of noise shows up.<br>

Multi-exposure should be able to take two exposures - a normal and a lighter one? Then combine the two to get more information from the original negative. I doesn't look better.<br>

I suspect the scanner to have bad dynamic range and somehow quite noisy CCD's.<br>

I have problems with underexposured slides as well - if the slides are exposured correctly, there is no problems because slides have normal contrast and will give a full histogram - does not need much post-processing and so on.<br>

Is it better to use a slide copier setup with a DSLR, macro lens, take 5 exposures of each frame and combine them? It could be used for both negatives and slides. Or - will it be better using a better scanner? I need som advice.<br>

Again, the resolution is fine for me. 10MP or higher is fine for 35mm. It is noise and bad dynamic range that's my problem.</p>

[andylynn]

<p>I think you're actually having software problems. Does the Canon software have anything for exposure control? If not, have you tried it in Vuescan?</p>

<p>Otherwise, another thing you could do is use Photoshop or another program with levels adjustment to fix the histogram. Yes, you'd be throwing away 80% of your data, but sonce you scanned in 48 bit which has 256x as much data per channel as 24-bit, and you're going to end up printing at 24-bit anyway, you can afford the loss.</p>

[mattb1]

<p>Over and under exposed films are not easily scanned, even a drum scanner can not produce files that are what you want. The reason is the grain structure in the film is not good. The grains will be much larger and irregular and show up as what you may think is noise. Even doing manual HDR will usually produce a result that is less than optimal. The problem is the film, not the scanner or technique.</p>

<p>I'd suggest you try what the other posters have said, try scanning at low resolution and see how it goes. You may be limited to what size prints you can make with the over/under exposed film, even with traditional printing. So, you need to adjust both your expectations and approach.</p>

<p>Are you scanning to get a good histogram or for what you think will print OK? I liked the idea of scanning for a good histogram, and then adjusting in photoshop. That is, for transparencies scan so the highlights are near the right side of the histogram, but not much over. Then adjust the curves to get a good distribution of pixels and as few peaks and clumps as possible. Then in photoshop (or whatever you are using) adjust the file to how you want to see the image. The idea is to get as many different pixel values as possible to give you more tones to work with latter. Negative film is opposite, scan for the shadows.</p>

<p>IMO the epsons will not help you in this situation, or any. The canon should have more range and better optics.</p>

[peter_haagerup]

<p>I haven't tried Vuescan. I do not own a copy of Photoshop - usually, I use GIMP. GIMP does not support 24bit, so I need something else.<br>

What I really want is a automated process that will make the scans look like the prints, except higher resolution and higher dynamic range. I don't want to do small adjustment to each picture - the prints are fine and made automatically I assume. I want about the same solution - for digital images files instead of prints. One could say "Why don't you just scan the prints?" - My answer will be loss of dynamic range and low resolution.<br>

I have a lot of film to scan - I feel like I'm wasting my time because the quality doesn't match the prints.<br>

I understand it is hard to see the grain at the standard 10x15cm print size - I except to see film grain at my scans, and I do - but the grain is some kind of amplified with some really nasty red/purple noise. The prints look smooth, sharp and with solid colors - not flat and noisy at all.<br>

It cannot be true that I will need a dedicated high priced film scanner or a VERY expensive drum scanner to make scans that match the prints. If that's true - it's not worth it for me.<br>

If the Epson V700 scanner does the job, I will get that one and be able to scan a lot more in a batch. I would like to continue using Silverfast making the 48-bit scans and then use something else, fully automated for post processing making consistent results. I have tried Silverfast HDR for post processing, but it does not give me consistent results. Two almost identical frames can have different color temperature, contrast, you name it - while the prints are just fine.<br>

The reason I mention the Epson V700, is that I believe from reviews, that it is the best filmscanner for the money - flatbed or not. To get a little higher quality, you will need some of the very expensive Nikons, but it is not worth the extra price unless you will make really large prints. If that's not true - please correct me.</p>

<p> </p>

[janne_moren]

<p>Do the negatives look vaguely OK? Then you have some software issue with your scanning software, is my guess. It's for some reason severely underexposing your negatives as it scans. You should be getting a vaguely usable, but rather flat and perhaps washed out image by default, not something that is very, very dark the way you describe it. And if it's underexposing heavily, then pulling the brightness way up afterwards to compensate will also amplify the noise along with it, and that would easily account for the noise you see.</p>

<p>Also, have you checked that you're doing everything right with your hardware? Is the white sheet in the lid removed so the light can shine freely on the negatives? Do you see the light shining from the outside as you scan? Are you using the supplied holder for your film format - some scanners autodetect the holder and sets itself up accordingly.</p>

<p>Gimp is fine. I use it. That's not an issue. One tip (if it's Linux you're using) is to use UFRaw as a postprocessor for scanned images. It's meant for RAW files of course, but it can open TIF files (of the right kind) and is actually much better for setting levels and color adjustments than scanner software typically is.</p>

<p>As I wrote above, the optical resolution may be 3200dpi, but you're unlikely to get 3200dpi woth of scan data from a flatbed. Most likely your results are equivalent to about 2400 dpi or so - if they look a bit soft at 3200 it is completely natural. I have the V700 and it's true for that one as well. I scan at 3200, then downscale to about 2500dpi afterwards (with MF it's still way more resolution than I need anyhow).</p>

 

[peter_haagerup]

<p>I thought of making a little automated script with imagemagick to take the raw 24-bit scans and convert them into 24bit positive looking like the print. Then refine it, and then use that script for ALL pictures shot with Kodak Gold 200. Then I could make another with slight changes that will work for other films as needed. Simply bypassing Silverfast's NegaFix and such. But I think it will be too complicated for me.<br>

Is it possible that you could send me some scans you made with the Epson V700? I would really like to see what this scanner can do with negatives. I don't care about slides because I know they will look just fine. Maybe I'm asking for too much... I would love too see what the Epson can do with normal color negatives.<br>

I actually use a combination of Windows XP, Linux (newest Ubuntu) and Mac OS X.</p>

[mendel_leisk]

<p>I'd concur regarding the optimistic resolution: flatbed scanners typically advertise scan resolutions that are doable but there is a lower practical ceiling on resolution, likely around 2000 dpi.</p>

<p>Try it out: scan at different resolutions and examine the results.</p>

[peter_haagerup]

<p>If it is true that my Canon scanner is fine, then it must be a software problem. Silverfast HDR post processing software is not doing what I want.<br>

Of course I could by the Epson V700 and scan twice as much in a batch, get a little more resolution and so on. But I will still have the post processing problems unless I get some better software.<br>

I have tried UFRaw - I don't think it will let me do negative to positive conversion - I found out that it will not open 48 bit TIFF as well.</p>

[janne_moren]

<p>Peter, first, you use the scanning software to invert the image and remove the effect of the orange mask. I'm sure Silverfast can do it. In fact, if it's not doing it, that indicates that you haven't set up the software. Have you actually set it to scan "color negative", for instance? If the software thinks you're scanning a print, not a transparency, then it will neither invert the image for you, nor will it activate the scanner backlight, which would explain why your images are very, very dark.</p>

<p>UFraw will open 48 bit TIF files. I use it for that. But it is picky about the exact file format. From Vuescan I specify 48 bit file, no compression, no profile.</p>

[mattb1]

<p>No offense Peter, but you may want to send the film to a scanning service. Scanning film is very labor intensive and will take alot of learning, and learning what under exposed images can not be scanned satisfactorily. You may be more productive if you leave the scanning to a service. I think I'm going to do that, I have many rolls of film that I can not find the time to scan.</p>

<p>IMO you would take a step backwards in IQ with an Epson scanner and cause yourself more post scan work. I did the same thing, and only have a hand full of 35mm scans to show for it and no MF scans. Contrast that with what I got with a Minolta 5400 II and latter with a Cool scan, which number well over a thousand 35mm and hundreds of MF. Also, the Epson resolution is not real resolution, just marketing. IMO the Minolta 5400 II and any of the Cool scans are the best you can find for under $3,000.</p>

<p>HDR processing is not a miracle, it can add dynamic range but it can not make up color tones/graduations/detail that is not there on the film. So, you may be asking too much. As a test, take a few of your favorites and send them to a drum scan service and get a custom scan. The result should be about as good as you can get from the film. This will give you an idea of what to expect.</p>

[peter_haagerup]

<p>Thanks for all the responses so far.<br>

I can invert the image and remove the orange mask in my raw 48-bit scans using Silverfast. The problem is, Silverfast doing too much guessing how I want the image to look - even when I'm not using auto adjusting. Changing the crop area of an image is enough to make a world of difference. I do not trust that. That means that pictures taken at the same scene, the same day at the same time will have different color temperature and so on. That is the software problem.<br>

I might be satisfied with the quality of the scanner, if the software stop messing up my images.<br>

Simply, I need a tool that can invert the image, remove the orange mask and restore the contrast, without doing any guessing and auto adjusting. Of course I want some kind of auto adjusting, but not with that much difference between images that should look the same.<br>

Some of the images look cold with some kind of magenta color cast - others will be warm and have a yellow/green cast. I begin thinking that it is completely random how SilverFast HDR is converting my images.</p>

[david_f._stein]

<p>I've worked with some of these "simple" scanners for 35mm film (Epson 2450, 3200, V500) and it takes a quality 35mm color negative to get maybe decent results. I did much better on real flatbeds with quality optics (i.e. Umax in the olden days.) I would pare back and start fresh, trying to get the best you can out of that scanner and the Canon software. Silverfast is not a beginner's scanning software, even the SE version. Start over, Canon's own software, simple mode, etc. and see what your scanner can do. It's often better to learn and work to the limitations of whatever we own rather than chase after ... Sadly, development of and competition for dedicated 35mm film scanners has basically stopped. The last Canon and Minolta were reportedly good, but only Nikon to my knowledge still makes a pro level 35mm scanner.</p>