How do you measure the back length of a violin
I have looked online on how to measure a violin, and many point to "how to determine violin size for oneself" which is not my goal.
Looking at some articles and its drawings - I think the back violin measurements are measured with a straight rule. However, this video I came by show that one measures with "fabric" measuring tape and includes the curvature/arch at the back. She specifically states "not a straight rule." This caused me some pause. https://youtu.be/S0xMzLZguks
If that is so, then my violin is 36cm [!] and conventional wisdom is that it would be "big" for my petite frame.
When measuring with a straight rule, the back of my violin is 35.4cm to 35.7cm depending on the time of day when I measure. Its difficult to measure for a consistent number.
Please - could someone advise what is the best way for getting accurate measurement? [for a non-luthier]
The conventional way is to use fabric or plastic measuring tape, and follow the instructions here:
You can use a flexible metal or plastic straight ruler, that's what I use
So the length includes the curvature and arch of the back?
"Bottom line — is the violin length a straight line from point A to point B, excluding the arching?"
According to my rough calculation if the arching is 1 cm deep the difference between the straight top-tail measurement and the curved one that includes the arching would be between 0.5 and 1 mm. In the overall scheme of things this seems pretty insignificant.
Some measurements are taken with calipers. More often, they are taken with a tape or flexible ruler. It's nice when they specify which was used...
@George Huhn - my brain "melted" when you stated measurements typically include arching.
I'm afraid this is a "grey area" - one of many in the violin business.
It seems obvious to me that what makes sense for "player sizing" is the straight-line distance from "point A" to "point B" (whatever those points are on the instrument and ignoring any "Einsteinian general relativistic corrections" for "space curvature" (:-)).
Unless otherwise noted, you can assume it was measured conventionally using a tape measure. Using a straight flat ruler to try to estimate the length by eyeballing it would be very inaccurate.
I always mention the size of my violas as "caliper", and not "LOB" (length over the back). Technical books will always be in caliper too.
It makes plenty of sense to me to measure over the arch with a measuring tape. Violins don’t have flat plates, and there’s no reason to treat them as if they do. Caliper measurements are useful as well, but most of the time it’s a lot less convenient to use them, and a caliper is not necessarily any more accurate than a caliper. Some posters or other technical sources specify the measurement tools or list both measurements, but when a back length is given, you should assume it’s taken with a tape unless described otherwise.
It seems to me that the primary reason for using the flexible tape is to avoid the parallax that one would suffer in aligning the marks of a rigid ruler placed along the arch with the edges of the back.
Cloth fabric tapes are notoriously inaccurate, that would explain the crazy numbers people are getting with them
@Paul - that was how I calculated it, until your last sentence that defeats me...
@George Huhn - thank you for clear concise clarification. I really appreciate that. Thanks for including that curvature measurements are for bouts as well.
Lisa wrote, "I also now wonder how one could transition from 360mm to say ?355mm and not lose muscle memory of left hand. Spacing would be different."
Sorry Rich but the volume explanation doesn't hold water for me. Among the violins that adorn my wall I have two that measure 362 mm; one of them indeed sounds quite viola-ish while the other doesn't. The former actually has the lowest ribs of all my violins (its arching compensates to some degree) while a third one with very high ribs that I wondered might be a tiny viola doesn't sound anything like one! The two UK dealers and one auctioneer that I've discussed this with are similarly unsure of the reason why half a centimeter in length is deemed to have such significance but are reluctant to swim against the commercial tide so tend not to stock or promote larger instruments.
@Lyndon Taylor & @Rich Maxham – I hear an echo here which is “my measurements are inaccurate.” For kicks and giggles, I went ahead and took a metal tape and measured. The metal tape hooked to wood tail end, touches the highest arch, and to the top imaginary line above the purfling. It is 354.5 to 355mm. The fabric measuring tape is 360mm. My human eyes “see” that metal and fabric tape correspond well side by side. 5mm is huge, so I double-checked - I was looking at the wrong line on fabric tape. DOH! It is ~355mm by fabric tape.
Lyndon, I agree cloth tapes are inaccurate. Would it be possible to take a sheet of paper, place or on the back of the violin, mark the 2 points on the paper, remove it from the violin and then measure them with an accurate ruler? Would this account for the arc?
that would add the arc, might as well just use a flexible ruler or tape measure
I think that the most indicative measurement from the violinist's point of view is the linear one taken with the caliper, as this determines the distance from the hand to the violinist's neck (which is linear, not curved) and so the needed extension of the left arm. Of course it is more handy to measure with tape, but if the arching is very high the measurement is decidedly stretched, and therefore distorted. As a luthier, I consider the measurement with the caliper to be the only reliable one, the one with the tape only serves to have a very inaccurate general idea, which generates a lot of confusion for a luthier that is always dealing with linear measurements.
The problem with cloth tapes is that they're stretchy. A flexible metal tape would be better but then you risk scratching the instrument trying to follow its contour.
Paul - I get it. Violinists worry about fractions of a mm but violists think in inches...
There seems to be a lot of misunderstanding here about how the measurement is taken. First of all, the points used for determining back length are not on the highest points of the arching, and they are taken from the edge, which is not the lowest point, either. The amount that the arching changes the numbers is nowhere near what is being hypothesized, because the thought experiment is being conducted with improper assumptions. Violins don’t have flat plates, so there’s no reason that they ought to be treated as such in measuring them.
I certainly understand why luthier David Sora would find caliper measurements more useful, but as Rich Maxham points out, tape measurements are the convention among players and dealers. Buyers want to know the LOB by tape measurement to compare instruments.
As an incorrigible sceptic I don't buy the "harder to play" argument against larger violins either. People aren't all the same size (arm lengths must vary by at least 10cm across the adult population, finger lengths by a cm or two) so I fail to see why it has become the default assumption that one violin size fits (nearly) all.
Steve, If you were a small person or a young person stepping up from a three-quarter size to a full-size instrument, a smaller violin or even a seven-eighths size might be more comfortable to play.
Rich - you say "the back length can be compensated for by shortening the neck". Surely this will result in the same problem as I have with one of my longer violins, which is having to stretch the hand further to reach higher positions. When my thumb rests in the crook of the neck I expect my fingers to fall naturally in the fifth position. With my problem violin I'm a semitone flat which throws me rather badly in some repertoire.
Rich, you're correct - you wrote "viola-like" and I said "darker," which is the tone quality that it is popularly assumed that fiddlers prefer. However, I have never heard a fiddle player say that they prefer a body length that is more "viola-like" unless it was for a 5-string violin.
Rich - or you could leave the neck in its usual proportion to the body length and ask the player to extend their elbow about 1 degree more in first position. Seems like a small thing to ask.
Tape measures are useful to have but can be inaccurate. My mother had a good cloth one dating from about 1960 or earlier. I've bought a few on Amazon from China. The best are fibreglass nowadays(?) but some of the cheaper plastic ones can be a good 10% out. I compared them with a steel rule and threw the really bad one away.
Steel rules can be pretty out too. There was a batch made in India and sold by a big woodworking store a few decades ago that were awful.
Calipers can also be inaccurate. Not all of them are made to the same tolerances and one can easily come up with conflicting readings if the tool isn’t used properly or consistently placed in the same spot. A lot of people assume that, because calipers have dials or digital readouts, that they must be infallible. That’s not the case.
Steve wrote, "Violinists worry about fractions of a mm but violists think in inches... " It's taking every ounce of my restraint to avoid responding with "British humour."
Many a true word... I'm currently playing a 16.25" viola while in the past I've used a 17" and a 15.5" for long periods. Switching between them didn't bother me too much, but of course I probably never went above 5th position. For violinists 14" is fine but 14.25" is apparently too big.
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