Photomatix Pro is a Mac program that helps you merge multiple photos which were taken with different exposure levels into a single HDR picture. The utility features a comprehensive help manual, provides you with a wide range of output settings, and provides you with the quality images you need within moments.
You can import multiple pictures that were taken with various exposure levels or load a single image. Afterwards, the app lets you choose the preferred picture alignment and cropping options, reduce noise level and other adjustments for preparing the image for the processing. Click the "Align & Merge to HDR" button and the program will immediately generate a new picture.
In addition, Photomatix Pro will give you access to several visual effects and various output settings (Contrast, Blending, etc.) to help you get the exact result you need.
In my testing, the app offered me a quality output file after processing 2 images taken with different exposure levels. I easily configured the output settings even if I have zero experience in advanced image editing.
My only problem with this utility is that it supports a limited amount of image formats. For example, you cannot import RAW images or export to other formats than JPEG or TIFF.
Briefly, I'd say it's worth buying this app for your Mac only if the aforementioned flaw doesn't mean much to you and you plan on using the program often.
