Liveview and the Hoya R72

I tried the Hoya R72 with the EF 24-70 f/2.8L this morning only to find out that it wasn't quite enough light for liveview, although shooting outside instead of through my office window might make the liveview bright enough to see. I had heard that the EF 50mm f/1.4 had a hot-spot problem, but I decided to try it anyway to see if I could get liveview working. In fact, liveview worked brilliantly with this lens and I found that I could zoom and focus as usual through the Hoya R72. I took this setup outside and shot the image of our wall above using an exposure of 30 seconds at f/2.8 and ISO 400. There was indeed a hot-spot in the image, but it was very mild and a large, gradual exposure adjustment brush with a value of -0.60 fixed the problem in Lightroom. For processing, I did something new based on an article I found here. I used a custom DNG profile I created based on the article to help me find a neutral white balance in Lightroom and then moved things over to Photoshop CS3 only to switch the red and blue channels. An excellent video tutorial on creating your own custom DNG profile was linked in the article and can be found here. Based on these results, I may very well use the EF 50mm f/1.4 for IR images and I'll give the EF 24-70 f/2.8L another try in more light.