How to make a Comparator Mirror (PART 1) 

Hi Susan, We have just posted your kit. Check your email for a tracking number and some detailed instructions. Best Wishes, Chloe.

This is a brilliant post, thanks for sharing this knowledge. We'd really like to encourage folks to experiment in any way they like but it may be handy to say that we expect delivery of 1000 first surface mirrors just the other side of Christmas which we will be giving away (plus the cost of p&p)

There is the following of my experience... You see, I'm a maker more than a painter, so I tried my best to get a good tool... - Dimension of the boards: Since my printer can do some A4 (21 x 29,7 cm) I wanted to be able to reproduce two pages, so an A3 (42 x 29,7), so I opted to something just a bit larger to leave room for the tape : 35 (depth or the floor board) x 45 (large). It happens that 45 x 45 would have been better, since at least 5cm are unusable at the hinge (too parallel to the mirror to see any reflection), and the page should not be too close of the mast of the mirror. - Fixing the too boards; I used shelf brackets, but they were not perfectly square so I could not get a fix image. 1 degree of, and you spend hours to find where is your problem. I used some thick paper under one side of the bracket, and used a big set square! I first used a small one and could not get a good enough result : all this to say that I really believe that an approximative solution might bring you disappointments. - Diameter of the mirror: First I tried a 5cm, but it's too large. There is always a slight deviation from one side of the mirror to the other. The bigger the mirror, the bigger the deviation. With a 2,5 cm mirror, the deviation is much less visible, so you can compare on any side of the mirror without having the feeling that you missed the alignment the previous time, not remembering which side you used. - Mast holding the mirror: that was my biggest effort. I realized very soon that a mispositioned mirror of a few millimetres was inducing dramatic deformation of the resulting image. So I used a rigid mast (an aluminium tube, diameter 6mm), and used my 3D printer for the foot of the mast, and the mirror holder. My first foot was rather small, held by a single magnet. but the positioning was not precise enough. If you have touched the mast, no way to reposition it exactly to retrieve your reference. So I designed a system with two screw to millimetricaly position the mirror in height (and so get the 45°), and the azimuth to be strictly perpendicular to the front board. The tuning is done with a square page on the front board : if you get a trapeze on the floor; your angles are wrong! - I'm trying now to reproduce the "girl with a pearl" of Vermeer... Quite pretentious of me, but still his simplest composition, I think... And if I'm please with my system, I will publish my 3D plans on Thingiverse. - Oh, one more thing: I found that inclining the board was very comfortable to work seated instead of bending over the masterpiece... And it's also very useful be be able to juge the daub from a distance, where you see all your mistakes: one reason more to have a sturdy system to hold the boards and the mirror!

Even when I bought a first surface mirror, from an optics firm, they were only about 12 dollars on ebay. But I actually used 2" squares or rounds from Amazon, and just cleaned them off with paint stripper.

Great stuff Ben. I'll be posting a booster kit assembly video in the next few days.

@@paintinglabofficial Awesome! 😁

Hi jon, just email us at contact@paintinglab.com and we can get a kit to you. Thanks muchly for your comment!

Thats a very good idea Julio. left field, but very good!

This is a great comment, thanks Hondo. If the mirror is slightly off the source will swim in the mirror which is not ideal but still workable... if you try this youll see what i mean. In every other aspect we salute you! Best wishes PL

Hi Jane. Last point first. You don't have to centre the magnet perfectly but it always makes me feel better. As for the base magnet you will find that it is a tight fit but it will go. I would not advise hammering the magnet in but a little pencil lead should do the trick. Perhaps I'll demonstrate this.

Hi Jane. I have mentioned this in the new video (episode 8)

Sure, the wood doesn't need to be exact dimensions but I'm using about 12 inches by 9. at least one machine cut edge will be really helpful in achieving that right angle corner though.

@@paintinglabofficial Wow! That was fast! Again thank you!

inches. About 30 x 25cm

Hi there, the maximum size possible with any comparator set up is about 24 inches. However you can paint at any size going section by section or (as Tomas demonstrates in episode 5) you can use the comparator to paint small sections of detail into a larger canvas.

I tried that also, remembered them from my backpacking days. But maybe the color in the first surface mirror is actually better. First surface mirrors were cheaper, as I just got a 12 pack from Amazon, for the same price they were charging for a backpacking mirror. And then removed the coating of the plain mirror with some paint stripper on a rag.

If you are after an optical mirror there are many online retailers (although you'll be hard pushed to find one for less than $50). Our kit, which includes a mirror, is available by emailing us at contact@paintinglab.com. This kit is free although if you think it's useful we welcome donations and we will explain how this can be done in our first email to you. Many thanks for the question!

Everything starts with an email to contact@paintinglab.com. just send us your postal details and we'll send you a kit. If yould like to make a donation we'll also tell you how you can do that.

we certainly do. we ship to anywhere Sean. thanks for your comments btw.

@@paintinglabofficial Awesome. I sent you an email. Can't wait! Thanks

Same here. I likely saw that same video you did by James. I've never seen this before, although I use other "truing" devices and methods such as grids, proportional dividers, etc, when going for exact realism or portraits. I'm definitely going to get one of these comparator mirrors. Very intriguing!

Try it and find out.

Thanks Cesar, you have hit on the central question I have been asking for a decade. Have a look at my 'power of paint' documentary and see what you think.

​ @Painting Lab I don't believe it's cheating, it's more of a tool. Many famous portrait artists have always used grids and projectors.

My art teacher told me that there is no such thing as cheating in art. Use whatever means, methods, tools you can to create your own ORIGINAL artwork. The important thing is to MAKE ART. I wonder if the impressionists thought tubed ready made paint was cheating? Or if riding a bicycle to make a journey faster, easier, possible even was cheating. I'm the kind of person who is always looking for a better way to do ANYTHING ie easier, faster, cheaper, more accurately or effectively. This mirror idea excites me, along with augmented reality drawing aids.