Contact Sheets! Focus or No Focus

I was taught many years ago to focus the light on the baseboard when making contact prints. I raise the enlarger head, focus the light on the baseboard and make sure the paper will be full covered by the light.

But I just saw a printer on YouTube who de-focuses the light when making contact sheets.

What do you guys do? Does it matter? I've never noticed any issues but I'm curious what the consensus is.

What is there to focus on?
You don't want a negative in the negative carrier - otherwise there would be an over-lying image.
And the edges of the empty carrier should be outside the area of the photographic paper.
I guess if you are focusing somewhere near where the negative would be, you are assured that you won't be imaging the light source with your contact proof sheet, but I've never had problems with that.
If you standardize your contact proof sheet process - set the enlarger to a particular height and use the same carrier and lens and aperture to the same settings each time, focusing on the edge of the carrier will help you ensure that you are using the same effective aperture each time, so that is one argument for focusing.
But outside of that, I just normally set it up to cover just a bit more area than the proofing easel, and go ahead.
When I'm being methodical, I add an enlarging meter (Ilford EM-10) and the other variables to set the light level to a standard and then work from that.

Dave Gustafson said:

I was taught many years ago to focus the light on the baseboard when making contact prints. I raise the enlarger head, focus the light on the baseboard and make sure the paper will be full covered by the light.

But I just saw a printer on YouTube who de-focuses the light when making contact sheets.

Click to expand...

With a glassless film tray it does not matter. If there is glass you may project some dust on your contact sheet. Then it could make sense to get the glass out of focus.

Sanug said:

With a glassless film tray it does not matter. If there is glass you may project some dust on your contact sheet. Then it could make sense to get the glass out of focus.

Click to expand...

+1

Most even coverage will be with the lens stopped down. Putting a negative carrier in and focusing will help you determine that you are in the center of the lens field.

Yeah, I stop down the lens, put the enlarger at a set height, then focus... but the only reason is to have a repeatable exposure time. Not with a glass carrier. Reminds me that I have a bunch to do!

I use a light bulb hanging above the contact print frame and the negatives are laid in contact with the photo paper. There is nothing to focus.

When I use my Omega D2V enlarger as a light source for contact printing focus is first set on the negative carrier glass and then the negative carrier is removed. With focus set on air no spots will be projected.
BUT it is still possible to get spots! Once when making a small contact print from a thin negative that needed dodging and burning I had to set the enlarging lens to f45 to get an extended exposure time. The added
depth-of-field of the lens was able to reach up into the condenser system and project images of tiny dust flecks that were on the glass condensers. Spots only happen on skies and faces ... of course.