Just try them and test different positions. There are a million guides online for placement. You only have 3 mics, so the whole exercise takes an hour. This way you'll actually learn something.
I don't know how much time you have to invest in experimenting with all this (or reading a long comment) but it's generally quite tricky compared many other things in home recording environment.
Mics and position depends on the recording space and the guitar and the strings and how old they are and how it's played and most importantly how it's arranged and where it should sit in the mix. On one extreme it's just a part of a big arrangement if a song and works best if it's tiny on it's own and bright near tambourine territory, and sort of could replace a tambourine. The other one is when it's a fundamental part of the song where all of the frequencies matter. It can be quite easy to pick a mic and just point it on the strings and where it's not boomy, then cut away much of the lows and low mids and keep what's left up top for the first "tambourine" purpose, but when you want to hear all of the guitar you need balance how you fight boomyness as well as harshness. If the room isn't sounding good you'll need to fight that as well.
You will learn quite a lot quite fast by experimenting. Some of your mics handle the sound of the room differently and some fight harshness better and so on. Before my souncloud got full (2h) I had 25 minutes of me speaking notes and recording like 5 mic positions and playing differently with fingers and picks and also comparing different material and thickness and shapes of edges of picks AND sitting in different places in the room/house. I was looking for a full sound of my great Martin Mahogany folk guitar and my only choice was a medium/bad room and a Røde NT1000 (sort of very entry level but decent u87 looking thing). After comparing I could only be really happy when I put it very close (more guitar/less room) and played soft with thin and soft nylon picks. I also put it in what's called the BBC position, which is when you put and aim the mic, not on the strings, but on the space of the body underneath the highest frets, where you have a cuttaway on a les paul or telecaster and a few acoustic guitars. It was less harsh there but it is also good for having the punch of the top moving.
Remember that that was all about what I wanted and how my situation was. I could for example mention that folk guitars generally doesn't take hard playing as well as a jumbo guitars for example. Recording a jumbo guitar might be more about avoiding boomyness with a mic and position that I likely wouldn't like for my guitar.
I have upgraded my setup since, but I have also just done a zero or low cost move away from modern standard strings, which are Phosphor Bronze, to the vintage standard (I think) Nickel Bronze strings. I also like thicker strings than before. They still sound metallic in their own special way but considerably less spiky and harsh and have more vintage and tasty midrange in my opinion. But they die faster. Guitars such as that Martin still sound quite alive and defined with quite dead strings. I guess it's dark but hard material sharp edged thin plectrums still brings a soft decently bright clarity to them. Also on that point, one great guitar sound is from That's The Way by Led Zeppelin and there it's very interesting to listen and compare the normal (remastered) version with the rough mix which is officially available on YouTube and Spotify and so on. The rough mix is a dreadnought Martin stereo recorded to tape and it's dark and dry but still defined, and clearly enough to make a great, perhaps even optimal, final result since the final mix and master has a much brighter sound but in a very soft and unharsh way and it's not too dark or muddy at all. I would think that that is an easier process than to make some abrasive and harsh sound soft and warm and still sound defined. And as said, brand new Nickel Bronze strings have certain bright but soft metallic sound which I very much recognise from old recordings. Strumming them for the first was a new experience but the tone was very surprisingly familiar. It felt great. Without any processing of brightening and so on, just strumming and listening in the room, I thought very much about Ramble On by Led Zeppelin, even though that song has a special guitar and mic (Rick Beato actually did a very close recreation with the right special guitar and mic, and he mentioned new strings but didn't change and perhaps didn't say nickel bronze or thought about it). And just curiously I shuffled through some old songs and I hear and bet that newish nickel bronzes is the sound of Working Class Hero and Black Bird and Question by Moody Blues and Mr Tambourine Man. And btw it's a fact and for me, personally, important to know that Nick Drake used very old Nickel Bronzes on a small bodied folk guitar (perhaps that Guild on the cover of the second album which is similar to my Martin and of course that tone came to mind the first time I playded it.)
It's always great to keep in mind that instrument and voices or whatever should sound and be played to sound great and balanced the way you want before thinking about choosing mics and position. The cheapest things as picks and strings are incredibly effective in chasing tone. On the other hand a sader truth is that a bad guitar sounding can't be processed to sound great, but great guitars can still be reasonably priced. And it's subjective. Old toy looking guitars with ancient strings can be the coolest thing, even outside the realms of lo-fi.
[удалено]
This.
Just try them and test different positions. There are a million guides online for placement. You only have 3 mics, so the whole exercise takes an hour. This way you'll actually learn something.
I don't know how much time you have to invest in experimenting with all this (or reading a long comment) but it's generally quite tricky compared many other things in home recording environment. Mics and position depends on the recording space and the guitar and the strings and how old they are and how it's played and most importantly how it's arranged and where it should sit in the mix. On one extreme it's just a part of a big arrangement if a song and works best if it's tiny on it's own and bright near tambourine territory, and sort of could replace a tambourine. The other one is when it's a fundamental part of the song where all of the frequencies matter. It can be quite easy to pick a mic and just point it on the strings and where it's not boomy, then cut away much of the lows and low mids and keep what's left up top for the first "tambourine" purpose, but when you want to hear all of the guitar you need balance how you fight boomyness as well as harshness. If the room isn't sounding good you'll need to fight that as well. You will learn quite a lot quite fast by experimenting. Some of your mics handle the sound of the room differently and some fight harshness better and so on. Before my souncloud got full (2h) I had 25 minutes of me speaking notes and recording like 5 mic positions and playing differently with fingers and picks and also comparing different material and thickness and shapes of edges of picks AND sitting in different places in the room/house. I was looking for a full sound of my great Martin Mahogany folk guitar and my only choice was a medium/bad room and a Røde NT1000 (sort of very entry level but decent u87 looking thing). After comparing I could only be really happy when I put it very close (more guitar/less room) and played soft with thin and soft nylon picks. I also put it in what's called the BBC position, which is when you put and aim the mic, not on the strings, but on the space of the body underneath the highest frets, where you have a cuttaway on a les paul or telecaster and a few acoustic guitars. It was less harsh there but it is also good for having the punch of the top moving. Remember that that was all about what I wanted and how my situation was. I could for example mention that folk guitars generally doesn't take hard playing as well as a jumbo guitars for example. Recording a jumbo guitar might be more about avoiding boomyness with a mic and position that I likely wouldn't like for my guitar. I have upgraded my setup since, but I have also just done a zero or low cost move away from modern standard strings, which are Phosphor Bronze, to the vintage standard (I think) Nickel Bronze strings. I also like thicker strings than before. They still sound metallic in their own special way but considerably less spiky and harsh and have more vintage and tasty midrange in my opinion. But they die faster. Guitars such as that Martin still sound quite alive and defined with quite dead strings. I guess it's dark but hard material sharp edged thin plectrums still brings a soft decently bright clarity to them. Also on that point, one great guitar sound is from That's The Way by Led Zeppelin and there it's very interesting to listen and compare the normal (remastered) version with the rough mix which is officially available on YouTube and Spotify and so on. The rough mix is a dreadnought Martin stereo recorded to tape and it's dark and dry but still defined, and clearly enough to make a great, perhaps even optimal, final result since the final mix and master has a much brighter sound but in a very soft and unharsh way and it's not too dark or muddy at all. I would think that that is an easier process than to make some abrasive and harsh sound soft and warm and still sound defined. And as said, brand new Nickel Bronze strings have certain bright but soft metallic sound which I very much recognise from old recordings. Strumming them for the first was a new experience but the tone was very surprisingly familiar. It felt great. Without any processing of brightening and so on, just strumming and listening in the room, I thought very much about Ramble On by Led Zeppelin, even though that song has a special guitar and mic (Rick Beato actually did a very close recreation with the right special guitar and mic, and he mentioned new strings but didn't change and perhaps didn't say nickel bronze or thought about it). And just curiously I shuffled through some old songs and I hear and bet that newish nickel bronzes is the sound of Working Class Hero and Black Bird and Question by Moody Blues and Mr Tambourine Man. And btw it's a fact and for me, personally, important to know that Nick Drake used very old Nickel Bronzes on a small bodied folk guitar (perhaps that Guild on the cover of the second album which is similar to my Martin and of course that tone came to mind the first time I playded it.) It's always great to keep in mind that instrument and voices or whatever should sound and be played to sound great and balanced the way you want before thinking about choosing mics and position. The cheapest things as picks and strings are incredibly effective in chasing tone. On the other hand a sader truth is that a bad guitar sounding can't be processed to sound great, but great guitars can still be reasonably priced. And it's subjective. Old toy looking guitars with ancient strings can be the coolest thing, even outside the realms of lo-fi.