Lifting other fingers while practicing vibrato.
I've been practicing my vibrato a lot lately and I've noticed that I tend to lift my inactive fingers off the fingerboard more than usual. It happens especially when I vibrate on my second finger, my first finger unconsciously raises about an inch or maybe an inch and a half off the fingerboard. This wouldn't be so much of a problem except that it messes with my intonation when I need to use my first finger again. Do I work around this or do I need to correct it and how would I go about doing that?
I'm not a violin teacher, but I would say correct it. It's causing a problem (that problem being throwing off your first finger intonation), so needs to be corrected. I feel anything more than a centimeter or two (two centimeters is quite far) is too far - the further the finger needs to travel the more effort and delay there is until the next pitch.
It may not be an issue. When you practice vibrato, going from finger to finger keeping the vibrato as continuous as possible, does this cause a problem for the finger you are moving to? Practice this not just on adjacent fingers, but going from 1st to 4th and back - This can show you what adjustments you need to make to your hand, and lifting your fingers may be part of what your structure needs, or it may just be an affectation - Maximum relaxation should guide you.
Lifting fingers not actually in use should improve both vibrato and intonation. 1 1/2 off the wood sounds excessive; try 1/2 inch. If vibrato is throwing off your intonation then maybe the posture of the left hand is being distorted. Or, maybe it is time to renovate your intonation; scales, the broken-thirds scales, the harmonic minor scales, and arpeggios, all with one finger down at a time. jq
Play scales and arpeggios with vibrato on each note. Over time, increase the tempo. Insist on correct intonation. This will bring your fingers back down towards the fingerboard.
If you want to practice vibrato while keeping fingers close, or down, it's good to vibrate with two fingers at a time. E.g. counting in 4, place 1 on beat one, leaving 1 on, place 2 on beat two, leaving 2 on, lift 1 and place 3 on beat three, leaving 3 on, lift 2 and place 4 on beat four. (You can also leave more fingers on.) This is also a good way to practice continuous vibrato in a rhythmic exercise. Start with eighth note vibrato, proceed to triplet eighths, sixteenths, etc. Make each finger vertical on the beat, making sure the placement of each new finger happens precisely on the beat and in the same phase of vibrato motion. It's also good to practice various double stop vibrato exercises in a similar manner.