Sharpening for prints - what USM radius do you use?

[richard_arthur]

I've only recently started printing some of my photos, and I'm not

sure what's the best radius to use for the unsharp mask. When I do

the sharpening for the on-screen version I almost always use a

radius of 0.5 and sharpen between 25% - 100% (this is for Canon 10D

photos).

 

But it seems like I read somewhere that when you sharpen for the

purpose of printing you're supposed to use a larger radius and

you're also supposed to oversharpen slightly (sharpen beyond what

looks good on the monitor).

 

What radius and percentages do you typically use when sharpening for

prints?

[richard_arthur]

I forgot to mention that at this point I am primarily interested in making 4x6 prints, not larger ones.

 

(And yes I realize there is no specific "answer" and that the appropriate parameters depend on the particular image, the printer used, etc., but I am looking for a good general set of numbers to use as a starting point, if possible. Most of my pictures are highly detailed landscapes, BTW.)

[jbs]

It really depends on the Image and what you are trying to express.

For a general starting point I start at a radius of 3....;)....J

[fattfreddie]

As has been stated, it depends a lot upon the individual picture (I don't call them "photos" anymore).

 

I just fired up my Photoshop, and it was on 1.8 (radius).

 

Cheers,

 

Brett

[jbq]

I typically use a radius that will match 1/100 inch - 2.4 for a 240 dpi print (from a 10D, this is letter-size), 5 for a 500 dpi 4x6.

 

My nominal settings also involve 100% sharpening and 6 values of threshold for USM, and a 1-radius median filter when scanning film at 2400 dpi. I only deviate from those when appropriate (e.g. I increase the radius of the median filter when scanning ISO 800 film and when I know that I won't enlarge a lot).

 

For screen output I use a plain "sharpen" command instead of USM.

[mitz_molo1]

I found 100% radius 4 and threshold 10 is a good starting point then work it up or

down and found it equally sharp as what its on the slide. This is from after scanning

from 2900 dpi and resolution of 4000x3000.

It all depends on the resolution as so for a res of 3000x2200 radius good starting

point between 2.5 and 3.

[richard_arthur]

Thanks to all of you for giving me a few values to try as starting points.

 

Is it correct to say that, in general, for 4x6 prints you need to use a larger radius than if you were making large prints?

[richard_arthur]

Well, for what it's worth, I tried a few parameter sets and ended up deciding that radius=2.0, amount=150%, threshold=0 was best (out of what I tried). This produced as sharp an image as I've ever seen printed, but not too sharp.

 

This is for 4x6 prints of Canon 10D images professionally printed at a Fuji store in Bangkok, and it worked well for a set of 150 photos of extremely varied subjects (including people and landscapes).

 

radius=1.0, amount=150% kind of looked like the 4x6 prints I've typically seen from 35mm film cameras. Ok, but not as sharp as it could be.

 

radius=2.0, amount=250% was too much and looked unnatural.

 

radius=3.0, amount=200% was also too much.

 

I still need to experiment with radius=1.0 and a higher amount of sharpening (maybe 250%) to see how it compares, and also radius=3.0 and a lower amount of sharpening (maybe 100%).