Getting the best out of your ScanWit and MiraPhoto
Including some useful
hints and tips

And, after you've grasped the basics, check out my Advanced Guide

"This thing cost me three'undred quid! You mean I've gotta learn how to use it as well?"

You've probably already viewed the sample scans on the review page, and I think you'll agree that they're pretty good, but how difficult is it to achieve results like that with the Scanwit?
My answer has to be that, straight from the box, Acer's scanner may not give you the best possible results; it needs a bit of work to get decent results from it. Surprisingly, it's easier to get acceptable results from negatives than from slides.

The early releases of Miraphoto invariably rendered slides too dark at the scanners default settings.
Now, Miraphoto Version 2 has gone a long way to remedying this situation, and rendered these instructions somewhat redundant, but you may still find the following techniques useful if you use one of the earlier versions.
It's also handy to know how to deal with slides which scan too dark, or with a colour cast.

These instructions aren't meant to be a substitute for reading the manual that comes with the scanner; just some extra guidance that I think is sorely lacking in the makers documentation.

Getting it right, from the start
If you haven't already done so, calibrate your display before you go any further. Most monitors can do with a bit of help in showing correct colour and tonal range.
The little bit of time spent calibrating your monitor now will make matching your printer to your screen easier, and save you a lot of frustration, re-scanning and adjustment later on.

Check out your present monitor 'gamma' with my my exclusive 'Gamagic' estimator,
or with this link to a clever Java applet by Hans Brettel.
To use the estimator below, sit well back from your monitor and half close your eyes.
Then look for the place where the squares lose their colour, and are most closely matched to a neutral grey tone. The number beneath that section tells you the approximate gamma of your monitor. 

The "Gamagic" gamma estimator.
(You saw it here first folks!)

If the gamma of your system appears to be outside the 'norm' of 1.8 to 2.2, then you should take a little diversion to my gamma setup page.
The gamma page also tells you a bit more about gamma, and why it's important.

"A little free gif' for you"
If you've set up the gamma of your monitor correctly you should be able to distinguish most of the steps of this greyscale from their respective black or white backgrounds.
If not, it's back to the drawing board I'm afraid; or at least another shot at setting up the gamma.
As a last resort, try winding the brightness setting of the monitor up a bit, although you shouldn't have to.

A well adjusted monitor, viewed in subdued light, should reveal the left-hand greyscale down to 10 or below, and a difference in the lighter tones right up to 255.

You can also download this GIF file by right clicking over it and selecting "save image as....".
Then you can use it to check out your printer's ability to render a full tonal range as well.

Setting up MiraPhoto:
Now, if you haven't used MiraPhoto before, you must go through the MiraPhoto software with a fine-tooth comb and set it up properly, dealing with scan area and resolution, scan mode and calibration.

From now on I'll abbreviate MiraPhoto to Mira for my convenience as much as yours.

You must have the scanner connected and switched on; Mira will not open if it can't find the scanner. Insert the negative carrier into the scanner as well. (The reason for specifying the negative carrier is that it enables all six frames to be set up. At this point it doesn't matter if you actually have any negatives in the carrier.)
Open up the image editor of your choice, select Mira as the TWAIN source and open Mira.

I'd recommend initially setting the scan area to full-frame, the resolution to 1350dpi, and the mode to high-speed for each frame. This will enable you to quickly check your other settings without waiting too long for each scan.
You do this by clicking on each of the small preview frames in turn and then selecting the resolution and scan mode from the drop down menus situated beneath the row of frames. After you've done this, make sure the "Auto save config" option under the File menu is ticked, then close Mira.

"Oh no, not gamma again!"
Your next task should be setting the monitor gamma in Mira. Don't worry, this isn't the same thing as calibrating your monitor all over again, what it actually does is calibrate the MiraPhoto software to your monitor, and not vice versa. Doing this makes the preview window in Mira more closely match your final scan.
Go to "setting" at the top left of Mira and click on it. A drop down menu appears with "monitor gamma" as one of its options. Click on this and the calibration box pops up. You might already be familiar with this type of interface from setting up your system gamma previously. Ticking the "sync" option locks the slider controls together.
Matching the rectangles won't necessarily get the preview looking anything like the final scan!
Ignore the rectangular patterns, set all the sliders to 1.0 and close the box.
If you later find that the preview doesn't match the scan, then readjust the settings by comparing a scanned image directly with its preview. (The effect of adjusting the sliders can be seen directly on the preview window.)

Having done all that, Mira should be set up for your first scan.
Select the appropriate carrier and load it with some slides or negatives.  Make it easy on yourself, and choose well exposed slides, or negatives with easily recognizable colours that you know will print well.
The detailed procedures for slides and negatives are quite different, so I've made separate sections for each.
The scanner's colour response is slightly different for each of the various makes and types of film, so I recommend you choose the type of film you most commonly use when initially setting up the scanner.

Getting started:
Insert the carrier and open up Mira from within your image editor of choice. Select the frame(s) you want to scan by either clicking the red/green dot at the top right of the frames in Mira (green is selected; red is unselected) or highlighting the numbers in the little frame-number bar.

Now click on "Preview" and after a short focussing routine the scanner should start displaying the little thumbnails in the slide-frames at the top of the window. Clicking over any of these small frames will transfer its thumbnail to the slightly larger preview window.

Negative film users should skip to this link now.

Using Mira's curves tool:
I'll assume that what you've got from your scanner now is disappointingly dark, and possibly with a colour cast.

"Lighten up, dude"
Let's deal with the density problem first.
You might be thinking that this is simply a case of adjusting the overall brightness of the scan.... WRONG!
The brightness control is an almost useless function; in Mira or any other image manipulation software.
All that increasing the brightness does is turn what should be black to grey, and remove the detail from the brighter parts of the image. So don't touch that dial.

Here's what you actually have to do:
Bring up Mira's adjustment toolbar by clicking on the yellow button with the red, green, and blue dot symbol on it.

Now open up the "curves" tool by clicking on the little black and white graph-like symbol in the vertical toolbar.
You should now be seeing a screen like this:

As you move the mouse cursor over the straight line graph, it should change to a cross-hair sight. If you now press the left mouse button while the cursor is on the line, you'll be able to drag it upwards into a curve. Release the mouse button, and the line stays curved, but now it has a little dot on it, and the image should look a little brighter. (see opening animation).
If you make a mistake you can put the cursor back over this dot and shift it again, or even drag it off the end of the curve to get rid of it altogether. You can repeat this procedure at multiple points on the curve; re-arranging the shadow, middle, and highlight tones until the image looks right. The graph is a bit small, and this makes accurate adjustment a bit fiddly, but it gets easier with practise. If you make a complete mess of it, you can always click "reset", and start again - no harm done.

"Cast out those blues.....and greens"
A colour cast can be dealt with in a similar manner to the density, by clicking the red, green or blue selector and manipulating the curve for the relevant colour(s). For instance, a green cast will only need adjustment of the green curve, but a yellow cast will require adjustment of both the red and green curves.
By way of example; the slide in the illustration has a Cyan (greeny-blue) cast in the shadows. This can be corrected by adjustment of the green and blue curves as follows: Open the Green curve graph and place the mouse over the bottom left-hand corner.  When the cursor changes to a 4 way arrow, click the left mouse button and hold it down. You should now be able to drag the bottom of the straight line to the right. The green cast will reduce as you shift the line to the right. When the colour looks correct, release the mouse button. Now select the blue graph and do the same with that.
Don't worry if this all goes horribly wrong and the line curls up into a curve, if you keep your finger on the button you should be able to drag the curve back into the corner and straighten it out again.
The curves window is really a bit too small for accurate adjustment, but all it needs is a bit of practise to get used to it. As I said before, if you get into a mess there's always the reset option. (Unfortunately, this resets all the colours and the master curve, not just the one you've got selected, -  pah!)

When you're finally satisfied with the look of the preview, click the OK button to apply the correction.
If you look at the bottom of Mira's toolbar you'll see a funny little red symbol like a Zulu shield with four spears sticking out of it. This is the "apply all" tool and clicking on this will transfer the correction you've just made to all four slides. Do this now if all your slides appear equally dark.

You're ready to do your first proper scan now. Check that just the frame you're interested in is selected for scanning, and click on "Scan". A progress bar will appear, and shortly after it reaches the end of its travel, the full-size image opens on screen, most likely hidden behind Mira. Move Mira's window to one side and compare the full scan with the preview in Mira. If there's a noticeable difference, you must adjust Mira's monitor gamma settings again, but this time use the sliders to match the preview as closely as possible to the scan proper. Now you can close Mira and admire your scanned image.

There are probably improvements still to be made before the scan is finally to your satisfaction, but this should at least have got you an acceptable scan, and any final tweaks can be done in Photoshop. Once you get more confident and competent with Mira's curves tool, you'll be able to get very decent images straight from the scanner. There's really not much that you can't correct by manipulating the curves.


Curves versus Levels
I have to say at this point that you can also use the "Levels" or Histogram tool to arrive at more-or-less the same result, so don't take the above procedure as the absolute one and only way to do things. It's simply that, to my mind, the curves tool is more flexible and easier to understand, but it's really a matter of personal preference.
For a really thorough tutorial on the use of the levels tool, go to Wayne Fulton's website.
Don't be afraid to try out all the other tools. After all, you won't break anything just by playing with the software.
Of course you can also use Photoshop to do all your image adjustment, but I've found that it's quicker to use Mira for the sort of corrections that I've outlined here. Plus, all the settings are saved automatically with Mira, ready for use next time, or you can build up your own library of customised "config" files.
Also, I find there's some small satisfaction in getting a nice scan "straight from the scanner".

Scanning negatives:
In my experience with the Scanwit, negatives don't give the same problem of over-dark scans as slides, but getting the colour right can be a real headache. It's a lot easier if you've got a good print as a reference, so I suggest for your first few scans you choose some negatives where you've got some good prints to work to.

"A good reference eases you into the job"
Here's a flatbed scan of a print from the negative that I'll be using as an example.

I'm sorry, but that's the best I can do by way of a reference over the web!
You'll just have to take my word for it that it's a reasonable match to the original print (at least on my monitor)
The colour's fairly accurate, but a lot of shadow detail that was visible in the print has been lost in the scan.
Even so, it's better than guesswork in trying to get the colour of the final scan right.
As you get more experienced you'll need visual prompts like this less and less, but for the purpose of this tutorial I'll assume you're new to scanning, and need all the help you can get.

OK, you've got some nicely exposed negatives, and decent prints from them to refer to.
Load up that negative carrier and let's get scanning!

When loading the negative carrier, it's important to align the spaces between the frames with the dividers fairly accurately. Otherwise Mira's automatic assessment of the negative gets upset.

At this point I'll refer you back to "Getting started" to avoid repeating myself.

Now you'll need to select the most suitable film type from the menu, by clicking on the little film symbol at the right-hand side of Mira's screen.

Choose the type that matches the make and speed of the negative in the carrier as a starting point. You'll need to click on OK and close the menu in order to see the result, and it might not necessarily be the best possible colour rendering.  If the colour is way off, choose another type from the same maker and try that. You may need to try several types before you find a suitable match. As a last resort select generic and you'll just have to adjust the colour by hand.
If all this sounds a bit hit-and-miss, it's because it is. Even apparently identical films sometimes give better results using different film-type settings.  It's not the fault of the scanner, it's the fact that batch-to-batch variations of colour negative film are much wider than with slide film.
I used to have the same sort of problems making conventional photographic prints from colour negatives, but believe me when I tell you that scanning is far easier.

Having got close to the right colour, open up Mira's curves tool to make finer adjustments to the density and colour of the image.

As I've already said, negatives don't scan nearly as dark as slides, and it's often necessary to reduce the mid-tones with the curves tool, as in this example. Avoid over-bright scans, as they'll simply make the colour look washed-out.

Please refer to the slides section for details on using the curves tool to correct colour casts.

Then when you're satisfied that the preview looks close to the reference print, click scan.

We're close, but not quite finished yet.
For a lot of applications this result would be more than satisfactory, but we can do better than that.

Finishing touches:
Scanned negatives sometimes don't quite have the "punch" that a slide has, simply because they have an inherently lower contrast. This low contrast can be an advantage, and enables negatives to cope with a far wider subject brightness than slide film, but it usually means that the colour saturation is a bit lower as well.
Photoshop can easily rectify this by boosting the saturation of colours either individually, or altogether.
In our example, both the sky and the red roof are a little weak, so we'll just give them some help.

Here's the Hue and Saturation interface in Photoshop:

We'll use it to select the red channel and increase its saturation, which sorts out the red roof, and then use the blue and cyan channels to give the sky a bit more colour. Use these controls sparingly, it's easy to get carried away. Notice the "load" and "save" buttons at the side of the control box, they can be used to automate the process for use on future negatives of the same film type.

Perfect! (well, nearly). All of the tonal detail in the original print has been retained, but the overall result is more vibrant, and much closer to the sort of impact you get from a good slide. Altogether an improvement on the flatbed scan from the print.


Having got a good scan from one negative on the roll doesn't necessarily mean that all the others will scan well at the same settings. However, it isn't too much of a chore to adjust the scans individually, once you get the hang of it.

Despite these minor problems with negative film, I personally prefer it to slide film. Camera exposure isn't quite as critical for a start, and you get a much wider tonal range out of it, especially shadow detail. It can also be a bit more creative, in that you make the colour the way you visualised it when you took the picture, and don't slavishly follow the way that a slide film has rendered it. In fact, I think digital scanning has let colour negative film really come into its own, narrowing the ease-of-use and quality gap with slide film to a very close call.


Last but not least....
We mustn't forget about scanning good old-fashioned black and white negatives.
But monochrome should be a doddle.... shouldn't it? After all, there's no colour balance to worry about.
Well, yes, .... and no.
With a carefully exposed and developed negative there's no problem at all getting a very acceptable scan.
At least Mira gets one thing right, since in most cases everything can be left at default when scanning B&W negs.
On the other hand, improvements can usually be made to a "straight" scan of almost any negative, and black and white photography is usually far more about creating a mood than getting a straightforward record of the subject.
Here are two examples and the respective curves I applied to them.
In both these pictures it was important to have good separation of the lighter tones, to give detail and modelling to  the busts and the eggs, hence the steep upturn in the curves at top right. The difference is that the still life with eggs needed good separation of the dark tones as well, in order to keep the detail in the jar and weights nicely visible, so I set a second breakpoint in the curve, preventing it from sinking down too low. The shadow detail in the other picture isn't quite so important, and in fact the harsh shadows help give a bright sunny feel to it; lending a bit of extra "sparkle" to the highlights by contrasting with them. All that needs to be done by way of afterwork is to tone down the bare lightbulb in the shed. (Later)

So, as you see, there are no hard-and-fast rules to follow.  When it comes to scanning black&white negatives, you'll just have to trust your own judgement. Play with the curves. The results are almost instant, and it doesn't even cost you a sheet of printing paper. Be creative and have fun!
It's just a pity that most inkjets make a poor job of printing black and white.

"I'm no expert, but....."
I hope that what I've shown you here will be of some help in improving your results from the scanner, and save you some of the frustration and trial-and-error that I've experienced.
A little perseverance, and experimentation, will pay dividends in the quality of your results and the ease with which you can achieve them.

Known Issues with MiraPhoto:

How did defects in computer software and hardware come to be called "issues" anyway? It's such an innocent sounding word. Other goods would simply be called faulty or shoddy, and you'd be demanding your money back.  Maybe half the fun is outwitting the programmers (not difficult) by finding workarounds for their crappy handiwork.
Anyway, enough of that. Here's a list of the "issues" that I've found in MiraPhoto, and the solution, if any.

When is a RAW scan not a RAW scan?
Answer: when it's done with MiraPhoto.
The RAW mode should scan a slide or negative exactly as the scanner CCD sees it, but this doesn't necessarily happen in Mira: The automatic black-point and white-point correction is turned off, but none of the tools or filters are zeroed.  Doh!!!
With difficult slides or negatives, it's sometimes necessary to get them scanned into Photoshop before they've been messed about with in any way, so that you can make your own decisions about white and black points, gamma, etc. What you don't want is for filter, colour, and density settings to be left active.

The only workaround is to painstakingly open all the tools and make sure they're reset before you attempt to do a raw scan. Then save that configuration as "Raw.cfg" or whatever, for future use (don't forget to click "Apply All" before you save it).

Incorrect file size
MiraPhoto version 1.009 (the first release) reports the size of 36 bit scans incorrectly. It gives the 24 bit file size regardless of what mode you're in. Version 1.10 was supposed to correct this, but still managed to be a cock-up. It gives the 36 bit size all right, but every application capable of bit depths greater than 24 works in 48 bit mode, so the file size is still out by a third.  Are all programmers complete idiots?
Workaround: You just have to multiply the reported 36 bit file size by 2 (or one-and-a-third in version 1.1).

Automatic cast removel (sic) does not work
This function has no effect, whether the tick box is checked or not. Version 1.10 corrects the spelling mistake, but it still don't work, so whether it'd be of any use or not remains to be seen.
No workaround.

Monitor gamma setting is faulty
Matching the rectangles in the 'monitor gamma' setting of Mira will almost invariably result in a mismatch between the preview window and the actual scan.
In fact, the gamma should nearly always be set to 1.0 for correct matching of the scan to its preview.
The default setting of 1.5 for monitor gamma in version 2 of Mira is totally ridiculous.
Workaround: Ignore the patterns, and set the gamma purely by matching a preview to its final scan.

Auto buttons in brightness and contrast tool always give overbright results
The 'Auto' option in the brightness and contrast adjustment menu seems to always give ridiculously high brightness levels for slides, and has almost no effect at all for negatives.
No workaround. They are useless functions (all versions).

Symbols for RGB colour correction and Hue/Saturation swapped over on toolbar
Not exactly a bug, but it annoys the hell out of me.
And why didn't they make the Hue and Saturation control work like the one in Photoshop? As it stands, this control is just a fiddly duplication of the colour correction tool. Another waste of space! And that stupid 36 bit mode nag screen in Version1.10. Aaaaargh!

Workaround: I have to chill out more.


Some essential hints and tips:

Always make sure that your negatives or slides are spotlessly clean before scanning. A little time spent cleaning your film before it goes in the scanner will save you a lot of retouching work. Negatives are more susceptible to dust than slides, since any dust shows up as bright white spots on the scan. I recommend a rubber bulb type blower to puff away any loose dust and lint. More stubborn dirt can often be removed with a clean, dry cotton bud wiped gently across the film while it's still in the carrier, followed up with another blast of air.


When you use the slide carrier for the first time, leave four sturdy plastic mounted slides in it for a week or so, (when it's not in use, of course). This'll stretch those dreaded plastic spring-clips, and reduce the risk of breakage. It'll also make the slide carrier much easier to use, and less likely to distort slides in card mounts. .

You'll find that professional negative films, such as Kodak's Portra, Pro 100, or Vericolor 3 are easier to scan, and give superior results to film that's aimed at the amateur market, like Gold 100. The quality of processing makes a big difference too. Run-of-the-mill high street processors can give very variable results, and since it isn't easy to see bad processing on negatives, some of them get away with murder (of your film). If you persistently get poor scans from negatives, treat yourself to a roll of professional film, get it developed at a professional lab, then see the difference.

If you don't want any unpleasant surprises in your scans, stick to slower speed films of 100 ISO or under. Anything over 200 ISO is likely to exhibit an effect called "grain aliasing". This nasty phenomenon causes the film grain to appear magnified and exaggerated in the scan. It's often mistaken for CCD noise, except that it affects mid tones more than shadow or highlight areas. It's particularly noticeable in sky and skin tones, and can completely ruin the picture. I've attempted to explain exactly why in this article: The grain aliasing page

I've noticed a growing trend for high street processing labs to give a generous development to colour negatives lately. In other words they overdevelop the film. They do this to boost the contrast and colour saturation, thus making the finished prints more attractive to the unwashed masses. Unfortunately, the side effects of this are blown out highlights that cannot be scanned or printed, and a drastic increase in the graininess of the film. Avoid processors that use this trick like the plague. For scanning purposes, it's better to have a slightly underdeveloped negative than an overdeveloped one, and better yet, one that's correctly developed.

Adobe Photoshop is arguably the best image editor around, but quite frankly its memory management is terrible. Open 2 or 3 large image files at once and it'll cripple your computer. The only remedy is to save the files, close Photoshop, open it again and work on the files one at a time. For the same reason, don't use Photoshop for batch scanning at high bit depths and resolutions. By frame number 4 the whole operation will've ground to a standstill. It's faster to batch scan in JASC Paintshop Pro, save the scans from there, and use Photoshop for editing only.
Note: PaintShop Pro can only save files in 24 bit format!

Target your image adjustments to the final use of the scan. For instance, it's better to make the image a bit lighter for web usage, since the majority of uncalibrated monitors show images too dark. For inkjet printing on matt paper you might need to increase the colour saturation, while glossy paper may need a different colour and tonal balance altogether.

When printing; always judge the final result in a good light, preferably daylight, and for the most critical applications allow 24 hours drying time, before you make a final judgment on the colour. Give your eyes a frequent break from staring at the monitor, especially if you're trying to make a decision on colour balance. Go easy on the colour saturation; colour perception is a very individual thing, and one persons pastel yellow may be another's dayglow orange!

Some slides and negatives just refuse to give their best straight off the scanner, and need extensive work in Photoshop. In these cases it's best to scan at 36 bit depth, and do all the work you can at that colour depth before changing mode to 24 bit.  The 36 bit depth allows you to alter the tonal curve of the image far more drastically, without the colour gradation becoming coarse.

If you intend to do further work on your images, don't use the JPEG file format to save them. Saving and re-saving files as JPEGs quickly results in an unacceptable loss of quality. Using TIFF, or Photoshop's own PSD format won't degrade the image every time it's opened, worked on and re-saved. Only use JPEG for storing your final images, and only then if small file size is the most important consideration.

If you're using the scanner for archiving old or valuable negatives or slides, there's a strong argument for saving the files to hard disk and/or CD before any manipulation is done to them, and in the highest possible bit depth. For the moment, this means 36 bit scans from the scanner, saved in 48 bit TIFF format. Yes, the files are big, but blank CDs can be had for about 50p each these days, and a 20 gigabyte HD is less than eighty quid! There's an interesting article on West Coast Imagings' website, it makes convincing reading.

Further reading:
I thoroughly recommend that you have a look at the Scantips website as further reading. It's packed with tips, techniques and FAQs on scanning and scanners. Go see.

Minolta have a very good site devoted to the basics of scanning, and although it obviously has a slant towards their own scanners, much of it is applicable to the Scanwit and scanning in general. Minolta's How2scan pages.

I've just discovered Acer's Scanwit manual download , in PDF (Acrobat) format.
It's in colour, and seems to be an improvement on the pitiful offering that was provided with my scanner.
It's on Acer's Taiwanese site, and the connection can be rather slow. Still, it's only 1.4Mb big, and I think you'll find it's worth the download time.

Adobe's website contains a whole mine of information about many aspects of using Photoshop, and they also have an excellent tutorial on Colour Management.


The Advanced user guide's still a bit rough round the edges, I'm afraid.
The Advanced User Guide


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Last updated: July 4th, 2001