Hi,

I had the same problem and yes it will spread to the whole plant and all your tomatoes. It's a Fungus, and it will kill you plants very fast. Thanks to Sharon Love Joy's book Trowel & Error, I found a recipe for diluted milk that saved my plants. I used a 3:1 solution(3 parts water, 1 part milk). First I trimmed off all the affected leaves/branches ( this will make your tomatoes look like scarecrows, but it's the only way)-Dont compost the diseased foliage.
Then spray with diluted milk for several days. I do it in the shade but early enough that the plants have time to dry before evening coolness sets in.

My plants are saved! I cant believe it worked!

BTW I live in coastal (June Gloom) CA, in case you were wondering about the plants locale.

Hope it works for you,

Ziggy

No it's not septoria leaf spot.

Here's a picture of what septoria looks like on tomato. You'll find lots of photos and info if you search on google.com with the phrase
"septoria leaf spot tomato"
but without the quotes.

http://hflp.sdstate.edu/images/Septoria%20leaf%20spot%20on%20tomato%20leaf2.jpg

Beyond that, the plants/leaves look in tough shape overall. Are they in the ground or containers. What do you do for water, fertilizer, etc? And how often?

Can you post an overall photo?

Here is a link that might be useful: {{gwi:1295331}}

I can't answer your tomato question, but It doesn't look like septoria leaf spot to me either.
As far as the pepper plant, you might be overwatering. Peppers do not require large amounts of water, much less than a tomato plant. In fact I usually don't water my pepper plants unless they are so dry they start to droop slightly. An overwatered pepper plant will not do well at all. If the plant is small, you might also consider picking any flowers or peppers started on their until the plant is put on a little more size and looks more robust.

kendra