og Posted July 1, 2003 Share Posted July 1, 2003 While doing some horse-riding in Bolivia (hum... I must say that I was very concerned just about staying ON the horse at that moment), the front element of my lens Vivitar 19-35 got some bad scratches. There are some deep scratches (into the glass, 5mm long) and several areas with a LOT of smaller scratches... You don't need a flashlight to check them - they are here to stay, and they speak loud! I can see the result (flare, very low contrast..) all the time, even on small prints, with the hood, no sun around... I will try to use some black ink on the scratches, however I heard about the possibility to use some liquid (ammoniac ?) in order to spread the coating left back onto the small scratches... An idea about this ? Link to comment Share on other sites More sharing options...
stephen hazelton Posted July 1, 2003 Share Posted July 1, 2003 Sounds like time for a new lens! Link to comment Share on other sites More sharing options...
alex_lofquist Posted July 1, 2003 Share Posted July 1, 2003 Deep scratches can be helped by filling in with India Ink. I wouldn't bother with coating abrasions as you won't have any way to build up the 1/4 wave thickness needed in single coating (not to mention multiple coatings). If it bothers you may be worthwhile to have the front element replaced. To retaliate on the horse, you could enter him in a local race and see if it gets "scratched". Link to comment Share on other sites More sharing options...
carl smith Posted July 1, 2003 Share Posted July 1, 2003 With that lens its far more cost effective to just buy a new one rather than get the front element replaced. Link to comment Share on other sites More sharing options...
douglas_green1 Posted July 1, 2003 Share Posted July 1, 2003 Ohhhhh Whilllbuuurrrrr! What's that glue factory truck doing near my stall? Link to comment Share on other sites More sharing options...
frank uhlig Posted July 1, 2003 Share Posted July 1, 2003 I hope the lens did not scratch the horse, hee-haw, hee-haw ... Link to comment Share on other sites More sharing options...
og Posted July 1, 2003 Author Share Posted July 1, 2003 Alex: I wouldn't be able to hurt that animal. I love horses... Especially roasted with a good sauce (French habit ; ). I guess, I will try the ammoniac thing and tell you more about the results... Link to comment Share on other sites More sharing options...
phule Posted July 1, 2003 Share Posted July 1, 2003 I feel your pain and all but this is one of the funniest subject lines I've seen in the photo.net forums. Link to comment Share on other sites More sharing options...
lee_brand Posted July 2, 2003 Share Posted July 2, 2003 I guess that the proof would be in taking a few shots. You are probably going to notice it fairly badly on that focal length though -are you going to mount a UV filter on your new lens?:-) Link to comment Share on other sites More sharing options...
og Posted July 2, 2003 Author Share Posted July 2, 2003 I'am back... and as expected, the Ammoniac didn't do much. then... On sale: Vivitar 19-35mm + photoshop plugins 'blur' and 'flare' included WITHIN the lens (unique feature): 1000$. This will allow me to invest in a 17-40 f/4 WITH UV filter. Cool! Link to comment Share on other sites More sharing options...
aardvarko Posted July 2, 2003 Share Posted July 2, 2003 i'll give you $5 for it :) Link to comment Share on other sites More sharing options...
h._p. Posted July 2, 2003 Share Posted July 2, 2003 I once had the bonnet of my car danced on by a cow - that put a few dents in it, I can tell you. To get back to Olivier's lens, the clever thing to do would be to take some really moody shots emphasising the effect of the scratches and sell the prints at £100 a time. Soon pay for a new lens! Link to comment Share on other sites More sharing options...
colin carron Posted July 3, 2003 Share Posted July 3, 2003 A haze of fine scratches is bad news. The big scratches often don't seem to make much difference. Try a repairer for advice then if the answer is a thumbs down claim on whatever insurance you have. Many household insurances cover photographic kit etc even when used outside the home. Oh..and can we have your assurance that no animal was hurt in this incident. Link to comment Share on other sites More sharing options...
og Posted July 3, 2003 Author Share Posted July 3, 2003 Colin, thanks for the advice, I'll check my insurance. Sorry, but I can't confirm that no animal was hurt during this experience: my back & bottom got their toll! The horse was fine, though... I have to say, that I really enjoyed that horse-riding in the Canyons of Tupiza. Yep! Link to comment Share on other sites More sharing options...
peter_mcm. Posted July 3, 2003 Share Posted July 3, 2003 In all these posts, I'm surprised no one has mentioned the precaution of keeping a simple, inexpensive UV filter on the lens at all times. It's a piece of advice I received when I first purchased my camera. Not only does it protect the lens, but also aids in better exposures. Replacing a $15 filter when it gets damaged is much less traumatic than a $200 piece of equipment being rendered useless. Link to comment Share on other sites More sharing options...
og Posted July 4, 2003 Author Share Posted July 4, 2003 Peter, I have an UV filter on most of my lenses. But here, it was about buying a $30 filter(77mm) for a lens that I would sell at the end of my trip for less than $100. I decided to take the chance, and not buy the filter... I lost! : ( I am not sure about the improvement in quality. I read several times that UV filters are not really efficient, and that you should take the filter off in order to increase resolution and contrast. Hum ? Link to comment Share on other sites More sharing options...
hique Posted July 4, 2003 Share Posted July 4, 2003 "...but also aids in better exposures" When did you get this from? Some sorts even afirm that UV filters decrease contrast and sharpness. I never heard about UV making better exposures. But yeah, protective. Link to comment Share on other sites More sharing options...
douglas_green1 Posted July 4, 2003 Share Posted July 4, 2003 A really EXCELLENT UV filter does NOTHING, except protect the front element of the lens. A less than excellent UV filter will degrade the performance of the lens. Link to comment Share on other sites More sharing options...
david_h._hartman Posted July 6, 2003 Share Posted July 6, 2003 <em>"I read several times that UV filters are not really efficient, and that you should take the filter off in order to increase resolution and contrast." -- Olivier GALLEN<br> </em><br> <rant><br> <br> This is like the dogma of religion for some. Ive never seen any proof from anyone holding this view. UV filters do what they are designed to do. They filter UV light within certain wavelengths specified. From a reliable source I read that most modern lenses have some UV absorption in the cement used to bond elements into groups. There are also may different degrees of UV absorption, may in gels perhaps a couple in readily available glass filters.<br> <br> The above statement is pure foolishness. I dont care who makes it. It is theatrically correct but in practice its much better to make sure the front element of your lens is immaculately clean when a camera is point into the sun. The easiest way to do this is to keep a filter on the lens almost all the time and wear out the filter cleaning it rather than the lens. Always use a lens hood even at night.<br> <br> I consider myself very lucky. In 33 some years Ive only dropped two cameras (cosmetic damage), trashed a 135/5.6 Componon-S (ouch!) and smashed a few filters. One filter was on a 24mm f/2.8 lens. This lens has a thin front element. If the filter had not taken the blow the front element would have and the lens would have been a loss. Todays replacement cost would be about $360.00 for the lens, the filter $24.00. The net savings: $336.00.<br> <br> Why people worry about the loss of image quality, a couple percent in contrast, a few lines per millimeter and then stop their lenses down to f/22, f/32 even f/64 in small formats is beyond me. The loss of contrast and resolution for stopping down is easy to see. You can measure easily the loss of contrast with an analyzer on an enlarger base board. You can see the softness in an 11x14 print. <br> <br> If your film is capable of 140~160 lines/mm and you already limit the image resolution to less than 68 lines/mm by stopping down to f/22 where the image projected on the film should be twice the resolution of the film are you really going to miss a few lines/mm? If anyone is that fanatical about contrast and resolution then they had best not stop down past f/5.6 and never open up more than f/4.0. Moreover if one is this fanatical about contrast and resolution they had better use only use 50/2.0, 50/1.8 or 50/1.7 lenses on 35mm. You loose more resolution by switching to a 105 or 24mm lens than adding a UV filter.<br> <br> A more sane approach is to put a UV, skylight or slight warming filter on your lenses, what ever you like. Keep that filter very clean and throw it out when damaged or worn. For apertures use something between f/4.0 and f/11. Shoot wide open if you need to and stop down more only if you are desperate for DOF. Macro may make you desperate but take care how desperate, a 55/3.5 macro lens set to f/32 and life size is really stopped to f/64. Now your resolution is limited to less than 23 lines/mm, a 55/2.8 or 60/2.8 to about 29 lines/mm. Use the best prime lens you can afford or select zoom lenses with short zoom ranges (2x to 3x).<br> <br> If a man or woman takes a photograph in a forest and the image resolution is 88 lines/mm would anyone know he had a UV filter on his lens?<br> <br> </rant> Link to comment Share on other sites More sharing options...
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