hi all
i apologise if this has been asked before, i could not find an appropiate answer in the forums.
is there a guide or mini tutorial on the techniques used to create alphas from photographs and scans in photoshop. I have tried and not got brilliant results.
any help would be greatly appreciated.
Best regards
tak…
It really depends on the nature of the photograph that you’re using, and the way that you intend to use the alpha. There really is no “one size fits all” solution because any two photographs can be wildly different from one another, and alphas can be used in so many different ways.
In other words, the more info you provide, the more readily people will be able to help you.
i have some hi res photos of skin and i want to take portions of the image and extraxk the surface detail to use as an alpha. So i want to get a pore alpha and wrinkle alphas etc. also i have photos of concrete and leather etc that i want to make into cracked skin and such.
hope this helps.
thanks once again.
Import your Photo : Menu Texture / import
Menu Texture / Make Alpha
You have your Alpha 
Use it with some Zadd or Zbub, Normal brush, Texture Enable, Alpha choosed, Stroke Drag Rectangle enable
Have Happy Zbrushing! 
Pilou
i dont mean how can i get my image into zbrush i mean what techniques do you use to clean up a photo make to make it useable as an alpha map.
for example
http://www.zbrushcentral.com/zbc/showthread.php?t=12480
this dude has made some lovely alphas, presumably from photographs, what techniques were used to do this in photoshop.
thanks again…
Hi Tak,
In the link you provide to the Polaris30 thread about seamless alphas he says he uses I-Tek (which is his favorite utility next to ZBrush) to create his library.
Sven
Take any photos
Change it in grey level
Play with contrast-light-egalize-saturation
That all 
Pilou
Ps You can also try that :rolleyes:
Pss Or the more simple : Create your own Alpha texture directly in Zbrush !!!
Take Any Alpha (there are some inside the prog (or draw anything and grabb it with the Mrgbz grabber(Auto Crop disable) = Alpha brush
After :
Normal brush + Alpha brush (here alpha n° 25) + Stroke Drag rectangle + Enable RGb & Z intensity = 100
Use the Tilde “~” for move the image inside the canvas for a tiling image (in french keyboard the key “%” )
Draw some brushing and move with the tilde and voila ! 
10 second realized (and it’s a tiling image / alpha now) Zbrush is the best crazzy prog for make speedy alpha-texture 
thanks for the comments, but i really was just looking for tips on how to turn a photo into a good alpha map.
Play with contrast-light-egalize-saturation, is a good start.
i was specifically interested in any levels, contrast etc tips.
has anyone been successful in creating alphas from photos of skin etc…
thanks.
tak
Like this anybody will be ask you more precisely!
Pilou
The problem is that every photograph is different, and each needs to be handled accordingly. The general tips you’ve been given already are probably as detailed as anyone can get on this subject. Settings that work for one image will not work for another.
ZBrush does offer features in the Alpha palette that can help:
Blur and Noise can smooth out or add artifacts to the alpha. Max will maximize the values between black and white. Radial Fade will soften the edges of the alpha. Perhaps most powerful is the AlphaAdjust curve. Using this, you can modify the alpha in some really powerful ways, and then use the Make Modified Alpha button to make your changes permanent.
To add to the excellent info you have already been given,
you can take any texture (photo) in zbrush and create an alpha from it. I find it does a much better job of creating the alpha than I can get from photoshop. Then you can use the settings in the alpha palette that Aurick mentioned or take that alpha into photoshop to further add level changes etc if you prefer.
edit…you also have the wonderful option of intensity settings, and focal shift and alpha curves etc etc etc!!!
Mostly tho…i get away with taking…say a skin texture…loading it into the texture Palette, in that palette you have the option of creating an alpha, from there I use ref settings to soften the edges and use max to max outhe ranges for more detail and not have to bother with taking it into photoshop. I have created a great many pore and wrinkle alphas this way.
And as Frenchy pointed out…Zbrush is fantastic in it’s own right for creating alphas for skins or whatever you desire. It is really a fantastically self-contained program…there is almost nothing you can’t do in Zbrush.
experiment! That’s more than half the fun anyway!