[TPIN] am I missing something

[scharcass at aol.com]

Recently I have been looking at some of my trumpet heros pictures..Usually, they are holding a trumpet (showing)..I noticed that some 

of their pictures show..the main tuning slide adjusted to about 1 1/2"  ....I guess 

I'm lacking in knowledge regarding the use of tuning slides to that extent...???

Please help me regarding this question.....

thanks again for your help

Rick s