View single post by Eric
 Posted: Fri Sep 15th, 2017 04:31
Eric



Joined: Thu Apr 19th, 2012
Location: United Kingdom
Posts: 4435
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I think this proves that you can get away with a lot of defects on the front lens provided there isn't any stray light....and that protection filters on the front only protect your investment....and not necessarily your image.

The 18-105 was a good all round lens. The only problem I encountered was getting sharp focus at 18mm in certain situations. For the life of me I can't recall what they were, but after discussing with David at ACS he told me it was down to the lack of infinity overrun (or something like that) which consumer lenses don't have, if you look at the 17-35 when focused on infinity the lens can still be rotated a fraction more with no change in focus. This is to allow heat expansion in the larger size glass of pro lenses. The lack of this , can cause a small degree of soft focus with IR at certain extreme settings. Well that's what he told me ....if only I could remember the settings when it occurred.

Incidentally, you said the lens was even hotspot free when wide open....wasn't certain if you meant focal length or aperture? In my experience the more stopped down, the more obvious the hotspot....so I wouldn't expect any distinct hotspot evidence if the aperture was wide open..

I also found that the longer the focal length, the less obvious the hot spot.

When having to use some of the Fuji lenses that had hotspots (as they were all I had with me) I was constrained to using apertures of f3.5-5.6 rather than the f8 I preferred for IR landscapes and zoomed into 35mm rather than the 18-20mm I also preferred.

The other arguement is that although the hotspot is more obvious with smaller apertures, it's smaller and more easily removed, whereas larger more diffuse hotspots are harder to correct as they influence more subject areas.

Ps I likeed the colour shots with the 16mm lens...it's about the right width to get expansiveness without distracting distortion. I often used my 14-24 lens at no wider than 16mm for that reason.

.......I do however think your lawn needs cutting.

:lol:

Last edited on Fri Sep 15th, 2017 04:40 by Eric



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Eric