28-135mm EF vs. 55-250mm EF-S, please help me understand crop factor.

[klavender]

Sorry for the newbie question but I've searched Google and couldn't really understand this. I have a 40D with a 28-135mm EF lens. I understand this is a APS-C camera and since the lens is an EF that the effective zoom is 44-216mm. I would like to get more zoom but the EF-S telephoto is 55-250mm. 250mm doesn't seem like much more that 216mm and I'm not sure it's worth it. I've also looked at the EF 70-300mm which would be 112-480mm. It's twice as much money and would think I would want it slightly wider at the low end.

Also, if I go with the EF-S 55-250 would the STM be worth it over the standard? I want a quick focus as this will be used mainly for wildlife. How does the standard and STM compare to the USM of my current lens?

[klavender]

TTMartin, those look great! Here's a quick squirrel trying to hide. Still happy with this $130 lens.

[ebiggs1]

Bob from Boston,

"I dunno, Ernie."

Like always, I try to stay true to, no matter what some derogatory remarks may be, what I see and I prefer.  I could not care less what others use or want to use.  I simply report on my findings. In my DSLR 101 classes, no body had the equipment I have.  So what, we used what they brought.  All were happy and so was I.

If it were me the lens would go back. There are too many good choices to put up with less than good gear.  I sent a Sigma 150-500mm back to SIgma three times to fix this exact issue. They couldn't. I sold it with the caveat that I didn't consider the OS (IS) to be working correctly.  I got $300 for it. Not saying anything, just saying.

The bottom line is to shoot good pictures.