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Thread: Alternative photos
09-02-2008, 01:01 AM #1038
I had bought Sigma Apo, Tamron, and Tokina lenses but ended up selling them or giving them away. The expensive Sigma Apo had its coatings turning cloudy and fogging all the glass elements and became unusable, which I had to throw away. The most expensive part of a lens is in the precision focussing mount, not so much the glasses. That is why brand name lenses are heavy and more a pain to carry around. They also can stand the test of time, weather, moisture, dust, etc.
09-03-2008, 07:59 AM #1039
Hi Taneepak, Sorry I don't quite understand regarding the focussing mount is the most expensive. But to my knowledge, I would say the glass & built quality are the most expensive part of lenses. Also the faster lenses (bigger aperture) thus bigger glasses will make the price increase astronomical... the Sigma you have, I think its not the coating turn cloudy.. normally thats because it grow fungus on the glass thus make it look cloudy
09-03-2008, 08:06 AM #1040
Anyway, I have to agree with taneepak this time. In terms of manufacturing or optical quality. No doubt, those originals are indeed better than those made by third party companies. Also, German made lenses are better than Japanese made lenses. I know, coz I'd made compairison between them in the past when I was young and green.
But I always think equipment isn't the key of getting "quality" pictures. In fact, it's all up to the one who use it!
So, just keep shooting!
09-03-2008, 08:17 AM #1041
09-03-2008, 08:19 AM #1042
Please correct me if i was wrong.
09-03-2008, 08:21 AM #1043
09-03-2008, 08:26 AM #1044
09-03-2008, 08:37 AM #1045
09-03-2008, 08:41 AM #1046
I wish I had a longer lens!
Took that shot while having an interview with a guy!
09-03-2008, 08:48 AM #1047
09-03-2008, 09:22 AM #1048
haha..ntg to do..
so decided to snap some photos and playing with my camera.
Last edited by george@chongwei; 09-03-2008 at 09:28 AM.
09-03-2008, 09:30 AM #1049
09-03-2008, 09:47 AM #1050
- I thought in post #1048, you were trying to show the before and after pictures of what happened to the trees...and
- your picture above, post #1049, was that taken in the parking lot of a car dealership??..
*btw, still waiting for your vacation trip pics, you promised to post here for us...
red00ecstrat (Stefan), i hope the interview didn't turn out to be a doozer..
Last edited by ctjcad; 09-03-2008 at 09:50 AM.
09-03-2008, 11:29 AM #1051
Normally a lens design has multiple elements, sometimes with one or two elements being cemented together. Each surface of each glass element, including the surfaces of cemented pairs, are given multiple coating layers to reduce flare. The layers of coatings can be as little as 2 to as many as 12. The Sigma Apo I had had most of the coatings turned greenish which clouded all the elements. I don't know why it happened.
Every lens has to be mounted on a mount. The mount must hold every element coaxial and with the correct separations, irrespective of ambient temperatures. Many thin, steeply curved elements cannot easily be fixed in a lens barrel. The provision of a focusing movement, and for elements to move axially as in a zoom lens design, greatly increases both production costs and difficulties. These difficulties are made even bigger by having to take care of the auto diaphragm mechanism and its coupling to the camera body. If you use cheap and light material like aluminium only instead of brass and a little aluminium for the focusing mount, you may save some costs but at the expense of quality and reliability. Even assembling the elements unto the mount must be perfect. If not the best lens scheme is useless. It is like assembling an intricate high price swiss watch.
For longer focal length lenses a long focusing mount, necessary for focusing near, is going to be heavy and expensive. Alternatively you can opt for a much shorter focusing mount, to cut down weight, length and costs, but this long focal length lens will not be able to focus very close up.
09-03-2008, 12:27 PM #1052
09-03-2008, 04:25 PM #1053
09-03-2008, 04:28 PM #1054
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