bent toe wrote in post #15556044
I have a question... if anyone knows.
I stumbled upon some specs on this specifik USM model (it's VERY hard finding anything about this version.. it's all about MKII or V) and this seemed strange:
Physical properties EF 28-80mm 3.5-5.6 USM
Weight 330g
Minimum length 77mm
Maximum length 77mm
Maximum diameter 72mm
Mount material Metal
Barrel colour Black
Barrel material Type 2 plastic
Weather resistance No Source:
http://photonotes.org …1=EF+28-80mm+f3.5-5.6+USM
Max and min length... is that the barrell? Wouldent that mean that it is internal focusing with no extending tube?
It does say:
"Extends when focussing Yes ............... No, I believe this is wrong
Extends when zooming Yes
Focus type Internal or rear focussing
E-TTL II distance data Yes " I used to have one. It is a very good lens and and yes, the front element moves in and out as you zoom. The lens doesn't really get longer, it is just the front element that moves forward inside the front of the lens. I don't remember it rotating at all, just extending. It's has been quite a while since I had this lens, so when you get it, please confirm it for us.
Because of this movement you can't put on the original lens cap if the filter threads are retracted.
Later lens caps have a smaller profile and can fit inside the front of the lens as the front element retracted. The squeeze tabs are flush with the sides and don't get hung up and it will slide into the front of the lens when the front element moves.
http://www.bhphotovideo.com …8mm_Snap_On_Lens_Cap.html
This movement also makes it difficult to use a CPL. With some CPL's the outer ring is too large to retract into the lens and it gets stuck, while on others the CPL will slide in but then you can't turn the ring to adjust the polarizing effect.
I got around this by using a Cokin 58mm extension ring to extend the front filter threads out beyond the end of the lens. If you did this on a Full Frame camera you could get vignetting but on a Crop camera it is fine.
http://www.bhphotovideo.com …_Extension_Ring_58mm.html
Here is a review of the EF 28-80mm 3.5-5.6 USM:
http://emedia.leeward.hawaii.edu/frary/toolbox2.htm