I agree the Peak Model 1 is good, but I still prefer the Micromega Critical Grain Focuser it will work from any point on the easel and has a great diopter so that I don't need my glasses once it's set. It is also made of metal so I don't have to worry about it distorting in extreme heat. I still have my Scoponet and Microsite III both work well, but the eyepiece is fixed and will only work from the center of the negative. which is fine until you start working on 20x24 or larger.
I have used most of them and I can't say the focus I can find with my eyes is any different from that found with a focuser.
Try it yourself: focus visually, then put in the focuser and see if any adjustment is needed. If not, then there isn't much point in the focuser. OTOH, I am 3 to 4 diopters myopic; if you are farsighted then the things may be a God send.
Not my experience. Maybe, my eyes are not as good as yours, but my grain focuser does a better job than I can do with the naked eyes. Having said that, I'm not sure that I actually need the accuracy of the grain focuser, because the depth-of-field blurs the difference between the two focusing methods.
I'm on the lookout for a new grain focuser. I have a plastic Paterson job, and it doesn't do a good job. It's pretty dim (being made of plastic) and doesn't really help focus anything. It's REALLY hard to tell when it's focused.
Can anyone recommend a good focuser, one that will last? The ones we have in our lab at school are all-one piece of metal, and they seem to do the job well.
I have two grain focusers, one that costs me $50 at Calumet about 12 years ago (1st image below) and one that costs me more than $250, five years later (2nd image below).
I mainly use the cheaper one, because it has a higher magnification (20x) and is very reliable. The other is better for focusing into print corners (the cheap one cannot do that), but I almost never need it anyway, and it's 10x magnification fails to resolve my film grain (MF and LF Tmax100 or 400 in D76 1+1 on 11x14 paper), which kind of misses the entire purpose.