Can a Magnifying Glass and Prism Create an Ignitable Rainbow?

[Graze]

Can combining a magnifying glass and a prism make a rainbow capable of ignition?

 

[Drakkith]

The magnifying glass would recombine the colors, at least to some extent, so you would probably have a white spot or stripe instead of a rainbow one. Also, to get the rainbow effect you must typically allow only a small strip of light into the prism, which would greatly reduce the amount of light available, possibly too low to ignite anything.