Buy A Slide Scanner Or Use A Service?

Written by The Slide Converter

Mar 10, 2020

DIY Slide Scanning Vs. Our Service

This page gives you the low-down on DIY scanning  vs our Unique service. It tells you what the adverts for scanning machines do not.

We look at the quality considerations and time taken to complete a scanning project using different types of scanner and we also compare this with using a scanning service and in particular what we believe is unique about our own service:

Comparing Scan Quality

In the world of consumer scanning machines, Dots Per Inch (DPI) are marketed as the indicator of quality.  However its many other factors such as dynamic range, focus, exposure and quality of the optics which govern the final quality.  

Below we put the available scanner types into perspective,  costs range from £50 to £3000.  There are broadly 3 types:

Scanners For The High-End Enthusiast

These are predominantly One-slide-at-a-time-scanners e.g. Nikon Coolscan 5000/8000/9000 ranges. Some will accept a carrier for a few slides to be loaded at a time e.g. Nikon LS-ED5000. These were considered top-end consumer scanners and gave good quality scans for between  £1500-£3000.  Nikon stopped making and supporting these scanners around 2009 so you may consider second-hand but do read the warning about second-hand scanners further down.

These scanners will typically complete a single slide scan in around 2-5 minutes depending on your scan settings. If you go mad with the quality and multi-pass settings you can wait 15 minutes or more for one scan! In the manual for these slide scanners, it will mention doing pre-scans to get correct exposure levels and focus for each slide as well. The software used with these scanners is complicated and prone to crashing. Just look up Nikon NX2 or VueScan software problems to see how many people are pulling their hair out over these issues. These consumer scanners are sometimes used by slide scanning companies which charge a premium for the quality but also to cover the costs of loading one slide at a time.

Flatbed Scanners (e.g. Epson V Series…)

So what about using a flatbed slide scanner? These are typically cheaper £300 – £600. A lot of the slide scanning companies use these, they are good for scanning Photos and large transparencies. It seems quick and easy to just “photocopy” your slides right? BUT these machines are not what they seem, they are SLOW. How about 1 hour to scan 12 slides at full quality! Scanning companies can buy 5 or 10 or these scanners and manage to get an effective throughput of slides or use very much reduced resolution to speed up image capture.

But what about quality…… Well, these scanners typically post headline Dots Per Inch (“DPI”) of 6400, 7200 or even 9600, in testing the actual resolved detail is much much less.  A typical example, the acclaimed Epson V750 (circa. £600) can scan 12 slides at once in around 80 minutes at a claimed DPI of 6400. However according to tests, he detail measured in the captured pictures was only 2300 DPI; this is equivalent to a lowly 7 Megapixel camera. This means you are throwing away half of the detail available in 35mm slide film.

This type of scanner is multi-purpose, it must be able to scan an A4 page in a few seconds or slowly scan 12 slides in 10,000 thousanths of an inch increments.  When you dismantle a typical flatbed scanner and realise the image collector is moved by a rubber belt you realise that the technology is being stretched and this unavoidably reflects in image quality.

But putting aside the issue of DPI as very much a marketing tool, lets go back briefly comparing the flatbed with the “one slide at a time scanners” costing £1500 – £3000 which I mentioned above.   Remember the manuals on both types of devices talk about pre-scanning each slide for focus and exposure settings to get the best possible scan?  So what happens on a flatbed slide scanner when you lay out 12 slides all with different exposures, focus and colour casts.  Well the software lets you perform an inital pre-scan and then adjust the exposure for each slide in the prescan, the subsequent real scan will take this into account.  If you are scaning a large collection this is completely impractical and you will almost certainly end up doing what I suspect most slide scanning companies who use flatbed scanners will do; just scan everything on the same default average settings and then sort out the picture electronically afterwards.  Electronic tweaking will never match the quality of properly exposed picture and will never do justice to the original picture.  These scanners have no apperture adjustment, no light intensity adjustment and often have fixed focus which is an issue because not all slides have the same thickness mounts.   Just imagine taking photographs with a camera and never changing the exposure settings but trying to correct this electronically instead!

Bulk scanning services using flatbed scanners are cheap because the scanners themselves are cheap so you can employ multiple machines to increase throughput.    Its even possible to scan more speedily in low resolution (2400dpi) and since these scanners do not typically reach their claimed theoretical resolution anyway there is little point making the scanner go through the motions of a HI-resolution scan when it is not adding any detail anyway

Other Cheap Scanners

There are some much cheaper slide machines, as low at £50, sold by high street names who you think would have more respect for their customers’ precious memories.   I would classify these devices as “gadgets” or to be really unkind “novelty toys”, rather than scanning machines.  Quality is dire, just read a few reviews if you are considering one of these.   It’s a case of you get what you pay for and the slide collections we see get the correct treatment to extract and preserve the full colour and clarity available from slide film.   If you have been unfortunate enough to have used one of these machines to scan hundreds of slides, you may even think this is the best image you can get from such a tiny slide, but I implore you to send us a few test slides to scan for you.  Its FREE just post it to us along with your email address and return details.    Alternatively have a look at our example scan page where you can get some idea of the clarity and depth of detail possible using the right equipment and knowledge.

Continues below…

For all DIY scanning solutions a major factor affecting the end-result is how much research / trial and error scanning you are prepared to do.  Expect to fiddle with settings, hit compatibility issues with later versions of windows (later than Windows XP!).  After the scanning you will want to crop out any slide frames, orientate the image, correct age related colour casts such as blue snow in Kodachrome slides or red colours in Agfa slides from the 60s and slides which have gone purple.  All of this takes a huge amount of knowledge, time and enthusiasm.

I do genuinely want this article to be of use to DIY scanners, as I was once, I’ve been though the same learning curve!  My tip is to run trial runs till you are happy with your process; not just the scanning machine part but the whole end to end process. Start with 10 varied slides and work up to some larger batches, all of these are for testing only.  Repeat the whole process right from removing dust or debris, scanning at the best settings, cropping, rotating, examining and correcting. It is really important to go all the way through to the final media e.g. If you are scanning to use the pictures for a DVD video or upload to Facebook, you need to ensure you have the correct image resolution and type.  For example, some DVD players will stall if given an image which is too large for the player to process or will show strange colour effects if the image is not restricted to “TV safe” colours when processing.  If you want to print or order photos online then send off for a few test prints.  In a professional setup, the scanner, monitor and print devices are colour calibrated and use profiles to ensure that what you see it what you get but this is not usually the case when DIY scanning.

In this way, you can avoid the heartbreak of spending weeks scanning only to notice all your slides are affected by a colour cast or are slightly softly focused. I’d suggest as a minimum, you need to experience scanning 100 slides, taking them through the whole process of cleaning, orientating, pre-scanning, scanning, fix defects, adjust colour faults and output to target format. And finally…if you are able to, project the original slide and compare it with the scanned copy. The acid test is, “Are you now prepared to thow away the original sides?” If the answer is yes, then you have succeeded although you may want to keep them for sentimental reason or a backup of sorts.  Although they will continue to slowly degrade over time you have arrested the degradation and captured the best available image.

Refining the end-to-end work process before you start is the best way to ensure you don’t end up re-scanning the whole project due to learning about a vital setting halfway through the scanning process. As part of this process I would recommend investing in a colour calibration tool to properly set up your monitor, this will ensure that the colours you see on your screen will be the same when printed, its a huge mistake to change colours to look good on an un-calibrated monitor. 

Conclusion on quality of DIY scanning:   

High quality single slide scanners work out very expensive per slide and making them worthwhile means scanning multiple 1,000s of slides which will take 100s of hours not just in scanning time but in post processing to get the finished image.

Flatbed scanners, in quality terms are the equivalent of using a low resolution camera and will rely heavily on electronic processing (e.g. Photoshop) to improve images.

 For both types of scanner, the software and settings are complex and there are lots of stability and usability issues reported.


Time Investment


We tend to focus on the scanning but this represents only one part of the total time to process an average project. 

Taking an example 1,000 slides, which we would clean, orientate, professionally scan, crop, colour and exposure correct and burn to DVD for £255 including return postage and a free packing kit to send the slides to us.   

This is the time you might spend on the same 1,000 slides as a DIY scanning project.

  1. Researching and choosing a scanner.                      
  2. Leaning the scan software, experimental scans, 
  3. Fixing PC issues, trying other alternate software,
  4. Calibrating your screen for colour fidelity.

    Sub-Total = 20 hrs (at least)

    During the experimenting and learning curve stage you have to resist the urge to just get on and start or you will end up doing the whole lot again. Physical scanning works out 2mins – 6mins per slide, depending on scanner and the settings you choose.

    Sub-Total =  33hrs (For low-resolution scanning) OR 99 hrs (For hi-resolution scanning).

    5. Rotating the image
    6. Cropping off the black border,
    7. Colour correction
    8. Saving back to disk.  

    These jobs depends on how much of a perfectionist you are but a rule of thumb is that an average of 1.5 minutes per slide, based on you having had some previous experience with the likes of Photoshop or similar software.

    Sub-Total =  33 hrs

    Total Project Time = 78 – 144 hrs plus cost of scanner

If you are looking for a good quality result, that can be achieved using equipment available to consumers, it’s easy to see that the cost of the scanner doesn’t stack up.

You would have already made an investment of anything between £350 and £2000 and then will have to work for up to 144 hours as well.  

You can cut some of the costs by selling your scanner at the end of the project and you can save a bit by also buying a second hand scanner.  This is where I have to give a warning though:  If you have considered buying a used scanner, and selling it on later, be careful.  Scanners are mechanical devices prone to internal wear and ingress of dust and debris and they do require servicing from time to time which means big bills from authorised service centres.  Any sellers claiming they have a nearly new £2000 scanner “only used to scan a few hundred slides” are almost always going to be concealing the fact they brought it second hand themselves and you will be the next in a long line of prior owners to take on the ticking repair time-bomb.  They can also be damaged in transit.

The Slide Converter saved me so much time. At first I thought it might be cheaper to buy a scanner and digitise the slides myself. But I wasted a lot of money on a machine, that could only copy a low number of slides per hour. I didn’t know how to colour correct my slides either and the quality was poor compared to what I recieved after asking the Slide Converter to do them for me. Thanks so much Daren! 
Rupert M.

Our Unique Service

At the start I mentioned that our service was unique and I believe it is….here’s why….

We convert all our customers slides at true 4000dpi. We do this using a custom designed and built industrial scale machine which automates the entire process of cleaning, handling and scanning the slides; this is not a scanner that one can just go out and buy. We load up to 1,200 slides in a batch, after mechanical and air cleaning they are scanned. The process is automated and fast. The machine makes adjustment on each individual slide for focus, exposure, white balance. We get an exact digital copy of the slide under ideal lighting conditions using a purpose built lightsource based on remote phosphor technology for even light distribution and high colour fidelity. Crucially, there are no mechanical moving parts involved at the moment of scanning, the image is acquired in its entirety in one brief exposure of the remote phosphor beam.

We take time to review the resulting images for colour changes in the slide caused by ageing of the dyes which occurs at different rates for different colours and is also dependent on the type of slide type and chemicals used in developing. We correct those defects using profiles we have developed through experience.

The machine and the full editing proces we have refind over many years enables us to offer the quality of a hand scanned “one at a time scanner” but we dont need to charge the same rates due the the automation. In fact, we can match or beat the many services which are using the flatbed scanners we mentioned earlier.

I hope this article has been thought provoking and if you are interested in our service please have a look at the rest of the site.

References: Scanner reviews Epson flatbed V750 https://www.filmscanner.info/en/EpsonPerfectionV750Pro.html


The reviews say it all!  

"I have just had my first batch of slides from ‘slideconverter’. Great quality and service. My first viewing was like stepping into the Tardis and going back to my early twenties. That you very much for the trip and the excellent service and quality. Highly recommended…”

– A. Bailie

"Converted about 100 old family slides, quality much better than expected, very happy with results, worth doing.…"

– Robb