Digitising tablets

[chiz]

I'm looking into buying a second hand digitising tablet for a research project, but having always used 'company' ones I'm unsure about the best places to look, and what to look out for/watch out for. I imagine a new unit will be out of our price range. Obviously it needs to be a reconditioned/recalibrated unit to ensure my squares don't come out rhomboid!

Anyone out there got any experience of buying these, new or second hand? What kind of spec of unit do you need for digitising basic archaeological plans? Rough costs or good models? Minimum size is to do A3 plan sheets, although will also be doing large numbers of old Group Plans so A1 would be preferable although not essential.

Any advice gratefully received!

[Oxbeast]

You could just get an A3 scanner and digitise the plans in CAD/illustrator/CorelDraw. You can set up a grid in your mapspace and snap your grid points to that. If you're a research project, you may be able to get OS plans and overlay your illustration onto them (i'm assuming that its summat urban).

[chiz]

intersting idea, and probably cheaper, but wouldn't scanning take as long as digitising for some plans? Its not just the cost of the unit, but of the time taken, I think we used to have to digitise 100 plans a day, except I used to plead RSI and get someone else to do it...

[oldgirl]

It might take slightly longer, in that you're scanning and then doing the digitising on screen instead of straight onto a digitising tablet. I've got a feeling, however, that there aren't many digitising tablets around now. (Come to that, A3 scanners aren't that common either!)

On the plus side with scanning you have a digital 'image' of the original as a scan, in case of coffee spills etc.....

[BAJR Host]

For me, I did as Oxbeast ... I have an Wacom pen tablet (cos I like it..!)
http://dpnow.com/2145.html not cheap but very very good

scan, digitise in Corel... also means you have a digital copy of your site plans

"Entrepreneurs are simply those who understand that there is little difference between obstacle and opportunity and are able to turn both to their advantage."
Niccolo Machiavelli

[ecmgardner]

As hosty says Wacom are far and away the best tablets... but also the most expensive. For what you're talking about you need to make sure you get a puck so it'll be compatible with CAD. It's CAD that does the calibration for you to ensure your squares are square.

As an archaeological illustrator this is kinda my bread and butter. The best solution for you will depend on your on site survey methodology so you can tie everything in accurately. (e.g. is everything planned by hand or do you have access to gps survey kit?)

As Oxbeast mentions you can get OS plans. But best practice for illustration is to ALWAYS tie drawings into the OS grid.

A tablet is an expensive extra but can be useful if you are looking to remove distortion in plans as you can take three known points on a plan using the tablet and with CAD calibrate it so it will remove any distortion within those points. (Gotta be 3 as it needs to remove distortion in two planes... 4 is better, obviously but it can extrapolate the fourth from three.)

Time wise there's going to be almost no difference as you've still got to digitise the plan whether you scan or not. By the time you've calibrated the tablet for each sheet as you go, it'd take the same time (or longer) than scanning.

I could write essays about all of this... if you want to drop me a line I'd be more than happy to try and help. Also checkout the AAI&S (Association of Archaeological Illustrators and Surveyors) Facebook page (hope the shameless plug's allowed?) as you should get some handy hints from the discussions there too.

[chiz]

thanks for all the replies, an A3 scanner would indeed be a useful bit of kit for illustrations as well, but costs a fair chunk, and an A3 Wacom tablet, well I could dream I suppose! Its down to versatility I guess, which is more useful for more tasks.
Out of interest anyone know if you can get a puck for the new Wacom tablets? I assume they are USB and there's no problem if the software/drivers are compatible?

The whole idea of scanning (it does take a while) then opening in Corel, tracing over etc etc, just seems a faff, rather than just doing it all in CAD, but I suppose that's what I'm used to when I had a choice of three A0 tablets...I guess you just trace one plan while the next one is scanning.

I'll have a look at prices for reconditioned A3 flatbed scanners and see how they compare to a reconditioned A3 tablet....
thanks again

[shavedmonkey]

You could try a trace programme like Corel Trace or GTX to convert raster to vector. It takes some faffing with the settings at first to get nice clean traces, and it will always need checking (but then so do all the others) but can be very effective when you get used to it.

[chiz]

Hadn't thought of that one, but think will keep it simple...I've mucked about with Corel Trace for converting line illustrations and figures to vector, and to be honest its too much faff for me for digitising plans though its great for one offs.
The plans would mostly be single context plans, or 'group' plans, and all need to be digitised as polygons for use in GIS. I think it would be far easier and quicker to just scan and trace/digitise without getting more programs involved, my pooter is slow enough already....

[BAJR Host]

have tryind corel trace.. nt impressed.. I found that I could trace quicker and mor accurately... so much faff spent tyding it all up...

get scannin!

"Entrepreneurs are simply those who understand that there is little difference between obstacle and opportunity and are able to turn both to their advantage."
Niccolo Machiavelli