Originally posted by V.rider Wow, thanks for all the quick replies. A lot of love here for the 55-300, and it does look like a great lens. My only reservations with it are I really wish they had put the silent DC motor in it like the 18-135 and I'm not sure how well I will be able to shoot hockey indoors with it. Can anyone tell me at what focal length you lose the f/4 aperture at?
When you zoom with the 55-300 or any lens there is not a "step change" in the aperture in reality but.....
......the controls of the body only show 1/3 or 1/2 stop so yeah it changes as you zoom in is step values.
I did my own experiment the 55-300 non WR and concluded it was certainly 2/3 to 1 stop "faster" than any of the other Pentax superzooms and any of the "bigma/bigmos" Sigma offerings.
f4 from 55 to about
120mm
f4.5 from 120 to about ?? - I'm not sure where it reads f5.0 from, but its closer to 200mm end.
f5.0 from ?? to about 210mm
f5.6 from 210 to 260mm
f5.8 from 260 to 300mm
Compare this to the 18-135 WR. f4 is only up to 28mm and the 18-250 is f4 only up to 40mm.
Anyway, varying aperture zoom tend to annoy me a bit so when I use these 2 lenses I tend to stick them on f8 for half decent sharpness (or f5.6 if I need a bit more shutter speed) so effectively they become constant aperture zoom lenses.
If i had a DA*60-250 i'd use it for sports etc but wouldn't take it on holiday due to the weight/bulk. The cost might limit the holiday budget also.
The 55-300 is definitely the best value for money with decent IQ in this range.