Instruct: Classify a given review into positive or negative sentiment.
Query: canon extender won't interface with Tamron lens used on Canon 30D

How disappointing! I expected the Canon 1.4x extender would fit my Canon 30D with Tamron 18-200 lens which I have used with 2 Canon cameras but alas the mount for the lens has a part sticking out so that the Tamron which fits on Canon camera won't fit on Canon extender lens. It seems it will only fit with a Canon fixed focal length lens. Would be nice if the ad makes that clear before ordering.