> --- "R.Sriram" <[EMAIL PROTECTED]> wrote: > > Hi all, > > > > I recently had an opportunity to buy a used Canon 28-70/2.8L at a > > good price and have been playing with it for the past couple of > > weeks. This lens was intended to replace my old 28-105/3.5-4.5. > > > > I was highly impressed by the optics and build quality of the lens. > > My first test roll on Provia delivered what I expected from this > > lens and it is very very good even at f/2.8. > > > > However my question is about flare. On some other lenses I've tested > > flare makes itself visible in the form of hot spots or starbursts. > > With the 28-70 I don't see this happening, however, this lens seems > > prone to "smearing"/"haze", i.e., it looks like haze over large parts > > of the image, resulting in loss of contrast and colour. Of course, > > this > > only happens when I point the lens at light sources / the sun / etc. > > > > The lens has always been used with the hood. I've tested it with and > > without a filter. The filter is an expensive B+W which is very clean, > > btw. > > The flare seems more prominent with the filter on. > > > > I was quite surprised when I compared this to my old 28-105 which > > showed > > much less flare or "haze" effects under the same circumstances. > > > > Question : Is this normal with this lens? Has anyone else experienced > > this? Should I be concerned about anything? > > > > Thanks! > > > >
> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Alex Z > Sent: Tuesday, March 09, 2004 5:02 AM > To: [EMAIL PROTECTED] > Subject: Re: EOS Flare on 28-70/2.8L. > > > Hmm, interesting issue indeed. > I shoot with 28-70L for almost year a half already (it imemdiately > became my main lens followed by 70-200/2.8L), so far had never > experienced any prominent flare even in potentially flare-prone > invironmental shooting. However I had never ran any tests shining > directly into the lens specifically to reveal it's flare resistance. > I also always use its hood and it is fitted with Hoya Super HMC UV[0] > filter on permanent basis, so far no specific issues with flare. > > Perhaps I can burn out a few frames specifically to test that soon, (I > plan certain environmental session) to check it out... > > Alex Hi R.S., The older B+W filters were not very well coated and even the new MRC coated B+W filters are not much better. B+W's MRC coating was developed to resolve the issue of B+W's coatings wearing off when cleaned. Hoya's high-line Super Hoya Multi Coated filters are superior to even B+W's newer MRC line filters. The Hoya S-HMC filters are 99.7% Tran missive, B+W's MRC coating is probably in the normal range of 93%-96% transmissive. The problem is that 3% lower transmission in B+W's filter is bouncing off and could be causing or aggravating the flare. If you having a flare problem with the filter mounted take it off. If the flare is localized you may have a thin layer of oil or possibly fungus developing on an internal element. New fungus is hard to see though I think you can get it into fluoresce with the right kind of light. There is also the possibility that one or more of the lens elements are chipped or fractured and causing the flare. HTH * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
