Look on the following web site. I believe this is bacterial spot. Symptoms: Bacterial speck is widely distributed. Symptoms may appear on any plant part. Leaves of infected plants are covered by small, dark brown, irregular patches of necrotic tissue that are surrounded by yellow halos. Disease severity is increased by leaf wetness from sprinkler irrigation, rain, or heavy dews. Control: Minimize wetting of the leaves by using drip or furrow irrigation. Copper sprays provide effective control. Joe Here is a link that might be useful: Texas Tomato disease site

Doesn't look like disease. More like an environmental glitch.

The white stuff are whiteflies and their eggs, we have an infestation problem with them in South Florida. Whiteflies are from the tropics and can carry a disease called tomato yellow leaf curl virus. Leafhoppers also carries it. Once your plant is infected with leaf curl virus, the plant will almost stop growing and not produce anything, there is no cure. I'm not saying whiteflies definitely carry the virus, they may not, but it is something I've very wary of. I was not able to grow tomatoes for the most of 2015 because of them. Whiteflies like warm temperature so there are much less of them during the cooler months. They prefer shade, warmth, and protection from wind. They are attracted to nightshade plants, the virus infect nightshade plants such as tomato, pepper, goji, potato, basil. But they are attracted to a wider variety of plants while not infecting them, like the "bidens" plants (common lawn "weed"), brassica crops, banana and other type of leaves that may provide good shades. This season growing tomatoes in spring with the cooler temperature I have less problem with them. Also with mulching and keeping the plants healthy reduces my pests issues. I notice whiteflies like to attack the lower sick leaves, so I pruned them and maintain a good airflow in the bottom.

I'm not finding photos of necrotic blight, but other blights show darker spots with a circular pattern not seen on my leaves. Also my fruit is unaffected. Septoria Leaf Spot sounds and looks similar to what mine have. Either way, the treatment is removal of affected leaves and a copper spray. I will do both as well as a preventative spray on my other tomatoes. Thanks, Omni.