Fun with a QX5 digital microscope. A personal review.

by David Walker, UK

  Notes on its use both as a toy, and with modification, its potential as a cheap imaging route
for the microscopy enthusiast.

Ever since the Intel Play™ QX3 microscope was first released in Autumn 1999, it has become firmly established as a fun, affordable and educational toy to explore the world of microscopy. This is reflected in the extensive resources for teachers and students that have been developed for it and the enthusiasts of all ages sharing their experiences and images, (see below for a selection).

The QX5 has recently been released in Prime Entertainment's 'Digital Blue™' product range which from the maker's website is based on a QX3 with significant upgrades to both hardware and software. (The QX3+ model released after the QX3 had a software update.) The stated upgrades are:

• The sensor is now 640x480, (the QX3 sensor had 320x240 usable pixels interpolated to 512x384 pixels).
• The top and bottom lighting are now 'ultrabrite LED's' rather than tungsten bulbs.
• Facilities to measure samples are included.
• The video frame rate has been increased to 15 frames per second.

Typical selling prices for the QX5 in Nov.2004 are £70 in the UK and $80 in the US (from Amazon websites).

Although marketed as a toy, the QX3 has also proved popular with some enthusiasts seeking a cheap route for digital imaging on the microscopic scale. So the author shares his impressions below of the QX5 'as is', but for fellow enthusiasts includes trials on improving the imaging.

The QX5 is attractively presented, well made and looks fun and 'cool'! The microscope is ca. 10.5 inches high.
The accessories are similar to those supplied with the QX3. i.e. a sample slide, tweezers, stage clips, pipette,
two stage containers and two sample containers. Software on CD and set up sheet.The box states
that an activity booklet is included but was missing in the author's unit, but can be downloaded.
   

Out of the box: As the QX5 is based on the QX3 it's essentially identical in use. It has total mags of 10x, 60x and 200x (for a 15 in. screen) and focusing stage. The microscope body can be removed from the stage for 'on the fly' image capture to the extent of the USB cable; 10x is probably the highest practical mag for studies off the stand. The makers have thoughtfully incorporated a real time 'image flip' in the software, so that subject movements aren't inverted as occurs with compound microscopes. This improves the ease of subject manipulation on the stage especially at the highest mag. Younger users may have problems with the delicate 'touch' required for manipulating and focussing subjects viewed at 200x.

The rack and pinion works fine and the focus controls are large. Focussing is a little tricky at 200x with some lateral image movement but not unduly so. The turret lens change from 10x, 60x to 200x has a positive feel.

Software: The software supplied is very easy to use and offers a range of features. The unit is supplied with Windows software. The makers and third parties can offer Mac compatible drivers and/or software for the QX3, but unsure if these will work with the QX5.

 
Image capture menu, the software resizes the computer screen to 800x600 during use. Buttons for top or bottom light, time lapse (1 sec to 1 hour), still or movie capture are shown. The brightness control doesn't alter lamp intensity but presumably the gain of the sensor. The live video shows no lag on the author's laptop with Windows XP (Pentium PIII 866MHz with 256MB RAM). Images are auto saved when captured. The 'arrow button' bottom left takes user to image editing page below. 
 

Image editing menu. 'Collection' button accesses capture images and video (also some makers' samples). The last captured image immediately appears in editing frame. Buttons on right access: a simple but functional paint / editing program, special effects, slide show compiler, printing. Images are autosaved in a proprietary .smp ('sample' format) but can be exported as jpeg or bmp. Button top right exits program, button bottom right goes back to live image capture menu.
 

The hardware / software supplied of the author's QX5 didn't offer the 'sample measurement tool' on the maker's website. (The box the QX5 came in mentions the improved sensor and lighting but not the measurement facilities.) The maker's were helpful who informed me that the 'initial release' didn't have this feature but the 'latest version' does. Apparently it's an upgraded hardware feature not software (if buyers of the QX5 have this feature in their example, I would be interested to know what it is).

Still image captures exported using the QX5 software are 512x384 pixels in size i.e. the same as the QX3 after interpolation from 320x240. Videos exported from the QX5 software are 640x480. Images captured with the QX5 using the WIA support accessed by third party photo-editing software are 640x480 pixels and show the same field as the 512x384 captures, so presumably the QX5 software is downsampling (the maker's have confirmed this). The maker's may have decided to retain the QX3's 512x384 capture size to ensure the original mags are retained in the QX5. Another benefit of downsampling is that 'as-captured' images from budget sensors usually benefit from resampling and post processing.

The author did a quick comparison between VGA images captured via the WIA support in Photoshop Elements (appears in File / Import menu alongside TWAIN drivers for scanners etc owned) and the 512x384 exported .bmp images from the QX5 software, but all captures apart from lens tests below used the QX5 software.

Setting up and using the operating software was intuitive; the set-up sheet was easy to follow but was printed in a tiny font. The software includes a help guide but no operating guide. The downloadable QX3 student (and parent) activity guides on the maker's website are excellent.

Objectives in use and characteristics: The three objectives are parcentral within an image capture field (ca. 2 mm off from 10x to 60x, and ca. 1mm off from 60x to 200x in the author's unit) so only the smallest subjects may need scanning to find a feature.  As for the QX3 the objectives are protected from fingers and dust by a replaceable flat plastic plate.

The bottom cowling of the main unit extends beyond the optics so working distance for manipulation is quite small. (ca. 9, 5 and 3 mm for 10x, 60x and 200x respectively). Smaller subjects benefit from being placed on a glass slide or piece of paper to manipulate with the fingers away from the cowling.

The test subjects below show that the lenses give a good account of themselves.

Lighting: the LED's give a good white light source, and although the author hasn't used a QX3 for comparison, should offer a cooler and better colour balanced source than the QX3's tungsten bulbs. The author's captured images didn't show any evidence of the pink cast noted by some QX3 users. The life of LED's are usually excellent but can be replaced by the user.

The implementation of the top and bottom lighting seems identical to that in the QX3. Thus the top light is mounted to one side giving oblique light. The bottom light is to one side of a white receptacle below the stage with a diffuser fitted in the stage. The light source is selected from the software, but top and bottom lighting can't be used together.

The top light at all mags. gives plenty of light for image capture although can benefit, as noted in the maker's guide, from additional top lighting. An LED torch in a simple stand would be a good choice to match the colour balance of the unit's lighting. For the user seeking an evenly illuminated capture area an additional top light is vital as the side mounted fitted light gives some light fall off.

The bottom light is sufficient for the 10x mag but is getting noisy at 60x and not intense enough at 200x for the sensor to work at its best. There's no easy way for the parent or youngster who doesn't want to pull the unit apart to improve the transmitted lighting.
 

Underside of stage with cowling removed showing the bottom LED, painted cowling and stage diffuser.
The limitations of using an offset LED and coarse diffuser is especially apparent at 200x mag.
The author has tried extending the LED legs to bring it central but this gives a hotspot.
 

The Molecular Expression's web site describe a selection of condenser designs to improve the QX3 lighting. Their side by side image captures show the dramatic improvement in quality when the bottom light is upgraded. The QX5 should respond to similar lighting upgrades.

Trial at improving the QX5 bottom lighting: Admirably, the microscope is predominantly screwed together, not glued, so ideal for the careful adult enthusiast to dissect, explore and improve upon.

To improve the bottom light the built-in stage diffuser needs to be removed. The upper and lower halves of the stage have to be split which isn't for the feint hearted as in the author's unit they were still firmly held together even with screws removed. Gently inserting one and then two thicknesses of stiff plastic card prised them apart but the stage plastic is brittle so requires caution.

With stage diffuser, bottom LED and light cowling removed, the enthusiast can experiment with any bottom light sources to hand that may suit (but beware of hot lamps near plastic). The author sat the microscope on a small 'cold' light box used for viewing 35mm slides and this offered a very even white light and bright enough to be used up to 200x (shown right). With care, perhaps with some securing lugs for the microscope base, this is a practical set-up for youngsters using safe low voltages (the next size up light box to the one author used would be stabler).

For the user who may be more interested in even, color corrected light than the youngster, improving the bottom lighting is worth doing. The captured images at all mags with the light box the author tried are much more pleasing as the light is brighter, even and unstructured, the built in diffuser gives a very coarse background to subjects placed on the stage. It also enables a mix of top and bottom lighting to be used where appropriate.

One of Molecular Expression's design improvements to the bottom light did suggest a simple two lens Abbe condenser and prompted the author to try a LOMO Abbe condenser which sits neatly in the underside of the stage with elastic band to secure, but for the most part, for practicality the author just used the light box. 

  Image gallery 1: Built-in bottom light cf external cold light box.
(The turret lens mags of 10x, 60x, 200x are used for the image descriptions below, but aren't true mags which are dependent on crops,
resizing, screen size and resolution.)

Three sets of three images of ca. 1 cm square of plastic gauze at 10x, 60x and 200x. Resized to 350 pixels wide from 512 pixels.

Line 1) using built-in LED bottom light, has a blue cast, structured background and lack of light at 200x gives noisy images.

Line 2) External cold light box used as shown above. Even, unstructured neutral lighting and less noisy images at 200x now possible.

Line 3) Line 2 images where masters before resize have Neat Image noise reduction algorithm and adjustments to tonal levels.

Image gallery 2: Built-in top light.
Images resized, no other adjustments. Stamp detail at 10x, 60x and 200x. Apart from light fall-off in top corners at 10x,
the built-in light works well, neutral colour and still bright enough at 60x and 200x.

Improvements to image quality: The use of even lighting makes a dramatic improvement to overall image quality. The built-in LED's and external cold light source used required little if any colour cast correction. 'Raw' image captures from a microscope can often benefit from adjustments to contrast, brightness, and tonal levels. Some noise is seen in as-captured images from the QX5 but resizing images from native size with a little resharpening if needed can give a smoother look. The author extensively uses the Fred Miranda WP Pro v1.1 plug-in for Photoshop Elements for downsampling. Various software packages can significantly reduce noise in digital images without undue loss of detail e.g. Neat Image and Noise Ninja. The author owns Neat Image and has used it in all the images below. (A 'Device Noise Profile' was created for each mag.)

Image gallery 3: Various subjects, mixed lighting using light box, post image noise reduction before downsampling and tonal adjustments. Slight sharpening to correct resize softening.

Image gallery 4: Video / Time lapse
Real time video can be captured or single frame with time lapse can be set in the QX5 software from 1 sec to 1 hour.
Progress is shown on the screen. The video is saved in avi format at 15 fps using Indeo 5.1 compression.
This is such a versatile feature I'm hoping to explore its potential in more depth and
share a video gallery at a later date. Here's a quickie.   

Alternative budget digital imaging routes for the enthusiast: Although like many enthusiasts, I own a variety of imaging routes for macro and micro, I was struck with how easy imaging from 10x to 200x is with the QX5. The field of view of the QX5 (0.9 -20mm) overlaps that of typical stereo and compound optical microscopes and digicams in macro, so is versatile in this respect. I would normally have bits and bobs on tripods, homemade gizmos dangling on the end of microscopes etc. The QX5 is particularly useful for 'around the house' type subjects. The stylus sequence above for example I have no single device that can achieve that mag range.

It is a toy of course, so the limitations of its lighting and lenses are seen when fine detail needs to be captured e.g. of prepared thin section slides. A better bet for the enthusiast in this case would be a digicam with macro or webcam / digital eyepiece (VGA models sell for a similar price to the QX5) on a compound microscope. An old but trusty favourite of mine is a lensless security style camera with 'C' mount attached to a microscope and using a video capture box.

For the enthusiast or parent seeking a more professional and versatile microscope, for about twice the cost of the QX5 there are optical microscopes supplied with dedicated digicams such as the Motic DigiScope 150 and 300. If megapixel images are required, the QX5 is clearly not suitable and devices to add a consumer digicam to an optical microscope would be one option.

One final thought .... digital microscopes are great fun and for easy image capture, particularly time lapse, but the images can't compare with the crisp visual images from a student optical microscope at 60-200x or good quality hand lens or monocular at 10x. In my view, if introducing youngsters to the macro and microscopic world, a digital microscope should be a complement to, but not a replacement for, simple and easy to use optical microscopes and hand lenses.

Comments to the author David Walker are welcomed.

Acknowledgements: To judge how the QX5 performed and operated compared with the earlier QX3 model and as a basis for my own trials of the QX5, the author is heavily indebted to the many who have shared their experiences and images from the QX3 on the Web. Notably past Micscape contributors' articles and Molecular Expression's superb QX3 resources.
Thanks also to Digital Blue's Customer Service Department who were very helpful with queries regarding the still image capture size and the 'sample measurement tool'.

Resources:

1) Digital Blue - the maker's website provides resources such as student and parent activity guides for the QX3 which are also applicable to the QX5.

2) Molecular Expressions Intel Play QX3 computer microscope - impressive and very detailed resources; these include the microscope's construction, mechanical and optical features, modifying to widen its versatility, interactive Java tutorials and many image galleries.

3) ' Using the digital microscope' by Brian J Ford. A manual written by the noted author and scientist for 'Science Year 2002' (UK). A beautifully presented and informative book on using the QX3, includes many project ideas. Purchasable as a book or the first edition (36 pages) can be freely downloaded in pdf format. 

4) Micscape contributor's articles on various aspects of the QX3 - includes images and videos. Type 'QX3' into search box.

5) Yahoo group QX3 - QX3 owners discuss the microscope and share images and tips.

6) ' Small beginnings - introducing digital microscopes in physical science' - a 24 page illustrated downloadable booklet in pdf format with practical advice on the uses and limitations of digital microscopes in a classroom environment, includes discussions on the QX3. Produced by 'The Science Enhancement Programme' (SEP).

7) ' Using the QX3 microscope' - web page on the '3D Photography' website describing how to take 3D images with examples.

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