could this be dust in the lens?

[jann1033]

#1 after IS, pcb and key repair, cleaned adjusted to fac spec

#2 before repair , before started sticking i think ( not postive exactly when i first noticed that)

i posted these 2 photos to see if anyone knows if the softness in the top one could be caused by dust in the lens...realize it's not the best representation but i tried to find one before and after fixing that had roughly the same contrast in the sky vs the object ( the metal and wood). just want to know if that is possible or not. it seems to me there is a lot more weird discoloration beside the edges of the uprights in the top one...is this chromative abberation?.
ok pic #2 is f4.5 1/60 28mm, #1 is f4.5 1/500 38mm it seems ( the 2 closest before and after repair i could get to that had at least somewhat similar subject..it would seem if anything the first should be sharper given the faster shutter speed..the jetty is probably a 1/2 mile or so long and i was maybe 2/3 down it ( guesstimation) but you can see the beach clearly while the bridge is maybe 100 ft long( probably less but i stink at gauging distance ) and even the trees on the side are soft. any thing else that would account for it except the repair that wasn't a repair( 28-135 is)IS is on for both, i checked the one after the repair( photo#1) since the whole day's shots were so soft i thought maybe i hadn't turned it on , i was standing roughly the same distance from the rails in both photos, where i first noticed the softness as well as the planks in the flooring( snow one the wood was bare, no ice etc on it) top one was raw so all i did was convert to jpg. bottom was jpg already so it's right from the camera( it says 1 on photobucket cause the first download didn't finish but it's not recopied or edited)

 

[mabas9395]

Its difficult to compare the softness of two photos taken at different apertures. I'm not sure which lens you were using, but most lenses will be softer and have more abberation wide open and the top one shows a f/4.5. The bottom one shows an aperture of f/8 which is the sweet spot for many lenses.

 

[jann1033]

deleted this post as i changed the photos and this no longer applies but mabas is not hallucinating... that post dealt with the initial photos

 

[tinksdad]

That's an interesting problem. Doesn't look like dust to me, too consistant. Looks cold, had the camera had time to adjust to the temp change?

 

[jann1033]

That's an interesting problem. Doesn't look like dust to me, too consistant. Looks cold, had the camera had time to adjust to the temp change?

yes i was out for about 1/2 an hr here and later about the same time( other times jumped in and out of the car) and it was cold but camera should have been ok, i've taken other stuff outside with different lenses and not had a problem.. hadn't been using this lens much period lately due to it sticking

looking at the two together, it almost looks like the first has some kind of haze on it but i know it wasn't fogged cause i had tried a cp filter to see if i could cut down on the glare when i took the river a few shots later and would have seen any fog when i put them on and off. i 'd just like to be able to tell them more definite than "the pictures look funny since the repair"

 

[tinksdad]

i 'd just like to be able to tell them more definite than "the pictures look funny since the repair"

Oh, I hadn't made the connection that was your repaired lens!! Sounds like you might have a problem.......

 

[mabas9395]

...which from what i understand should be sharp (f22)

Most people are aware that lenses tend to be soft wide open, but lenses also suffer from softness at really small apertures as well (like f/22). I think its something called lens diffraction. You can read about it here: http://www.luminous-landscape.com/tutorials/understanding-series/u-diffraction.shtml

But I'm sure others (Groucho, Oblio, MarkB, etc) can explain it in easy to understand terms for all of us.

Allthough, I see now that you switched out the 2nd picture, so all of this doesn't apply to this topic anymore (but usefull nonetheless).

 

[jann1033]

Most people are aware that lenses tend to be soft wide open, but lenses also suffer from softness at really small apertures as well (like f/22). I think its something called lens diffraction. You can read about it here: http://www.luminous-landscape.com/tutorials/understanding-series/u-diffraction.shtml

But I'm sure others (Groucho, Oblio, MarkB, etc) can explain it in easy to understand terms for all of us.

Allthough, I see now that you switched out the 2nd picture, so all of this doesn't apply to this topic anymore (but usefull nonetheless).

that is interesting as i thought i remember something different but obviously the brain was once again in hibernation. i did go back and change the f22 stuff though just to not add any confusion since i changed the initial photos( incase anyone looking is wondering "what f22? is she talking about"

 

[Groucho]

FWIW, dust on your sensor will usually appear as slightly darker circles on the photo - in my pictures, even severe dust was really only visible in big patches of solid color, usually the sky. I think in the film days, I think they called marks like them cigarette burns.

 

[jann1033]

thanks, i think that was just a ploy to give me less money for this lens since i have since read that pretty much any lens has dust in it since they aren't made in clean rooms, the zoom action sucks it in etc...i couldn't see dust but then again i can't see alot of things i'm shipping it back to
canon along with links to the 2 photos i posted and see what they can do to undo what they did do that made my lens a pile of doodoo ( well helped since it wasn't l glass before now was it )