Black chillis

I have been growing some cayenne chilli peppers this year from seed so as to avoid the hassle that comes with supermarket chilli-buying - that is, buying three, using two, binning one.

They were grown from a Sutton's Seeds pot thing - it was basically a bit of compost, some seeds and a container to propagate in. I got pretty good results and potted them out and they've been doing nicely outside. I ended up with six plants, though two were so stupidly planted that they never made it.

Anyway, I currently have four quite solid plants. They've needed staking to stop them flopping down but they're otherwise grand. Many fruit have now been produced but I've noticed some black patches appearing on them. The Internet seems a bit vague on the cause of these but I think I've come to a conclusion. This is what they look like:

There's a sort of burnt-looking region on this chilli. Now, at first this was the only chilli showing this so I imagined some sort of defect. However, several now show exactly the same thing so I researched online to see what the cause was. Internet reckoned:

1. Darkening before ripening to red.
2. Rotting.
3. Sun burning.

They seem good and firm and the one I cut up tonight (the one above in fact) was perfectly fine so no rotting. I'm not convinced they are going red. So that leaves us sun burning. I happened to notice that the black areas only appear on a single side of the affected fruits and that side matches the direction of the sun at around midday to 2pm - the strongest time for sun exposure, plus this is a heatwave year. In fact, if you look closely at the picture you can see quite a clear line showing what would match the strongest sun exposure.

I therefore conclude:

Black patches on cayenne chilli peppers are due to excessively bright sun.