what are the magnification sizes of tele converters?
Jun 25, 2015 11:23:34 #
OzarkGuy
Loc: Southwest Missouri
Please excuse any spelling errors. I am interested in knowing if there are any TCs with a factor smaller than 1.4x. A 1X would be ideal.
I do not know he correct way to continue this discussion so here goes.
If I could mount a 1x tc permanently I could effectively seal the sensor from contamination. Could change lenses under most normal conditions with only the possibility of contaminating the tc. All that would be required is a tc type attachment to both the camera and the lens with a clear glass lens in the tc.
does any of this make since?
I do not know he correct way to continue this discussion so here goes.
If I could mount a 1x tc permanently I could effectively seal the sensor from contamination. Could change lenses under most normal conditions with only the possibility of contaminating the tc. All that would be required is a tc type attachment to both the camera and the lens with a clear glass lens in the tc.
does any of this make since?
Jun 25, 2015 11:26:32 #
Jun 25, 2015 11:31:29 #
OzarkGuy wrote:
Please excuse any spelling errors. I am interested in knowing if there are any TCs with a factor smaller than 1.4x. A 1X would be ideal.
The factor is what the lens focal length is multiplied by. For example a 400mm lens with a 1.4x TC would give 560mm. With a 1.7x TC it would be 680mm. and with a 2x TC it would be 800mm. A 1x would offer no extra reach 1 x 400 = 400.
Jun 25, 2015 11:32:36 #
Why would anyone want a TC that doesn't add magnification to a lens. A 200mm lens with a 1X converter
would be a 200mm lens.
would be a 200mm lens.
OzarkGuy wrote:
Please excuse any spelling errors. I am interested in knowing if there are any TCs with a factor smaller than 1.4x. A 1X would be ideal.
Jun 25, 2015 11:40:50 #
They are called extension tubes and will allow you to focus closer.
Jun 25, 2015 11:53:59 #
Leitz
Loc: Solms
OzarkGuy wrote:
Please excuse any spelling errors. I am interested in knowing if there are any TCs with a factor smaller than 1.4x. A 1X would be ideal.
If you put a 1X on, say, a 200mm lens, your effective focal length would be 200mm.
Jun 25, 2015 12:21:30 #
OzarkGuy wrote:
Please excuse any spelling errors. I am intereste... (show quote)
Somewhat of an idea .........could not be made without moving the lens further away from the sensor than what it needs to be - and, so acting like an extension tube preventing infinity focus. You could put glass in it such as to retain infinity focus - but there would be a significant loss of IQ.
Jun 25, 2015 12:56:01 #
Leitz
Loc: Solms
RichardTaylor wrote:
They are called extension tubes and will allow you to focus closer.
In fact, tele converters are generally called tele converters.
Extension tube are generally called extension tubes.
Jun 25, 2015 13:06:29 #
OzarkGuy wrote:
Please excuse any spelling errors. I am intereste... (show quote)
While I understand your intent, I contend your concerns may be over-zealous. These things are made to have the lenses changed. Granted, precautions need to be taken, but it doesn't render the camera useless if some dust gets on the sensor, and cleaning the sensor is not that big a deal.
Jun 25, 2015 13:41:26 #
Now that I think about it, Canon made just such a thing - a 1.2 TC built into their FD to EOS adapter to be used only with telephoto lenses 300mm and longer ....
Jun 25, 2015 13:42:06 #
imagemeister wrote:
Now that I think about it, Canon made just such a thing - a 1.2 TC built into their FD to EOS adapter to be used only with telephoto lenses 300mm and longer ....
and allowing infinity focus .....
Jun 25, 2015 13:51:43 #
Jun 26, 2015 05:58:24 #
after rereading your post I get it. how about trying my cure, I carry a clear lastic bag that came with something I bought, in my camera bag. I put the camera and the new lens in the bag ,swap lenses and then return the swaped lens to my camera bag. no expense and no loss of light.
Jun 26, 2015 06:37:39 #
The Sigma SD series of DSLR cameras have a dust barrier just behind the lens.
Dust-Aid makes a dust shield for Canon cameras that seals off the mirror chamber from dust when changing lenses. Here is the website:
http://dust-aid.com/dust-shield/
Dust-Aid makes a dust shield for Canon cameras that seals off the mirror chamber from dust when changing lenses. Here is the website:
http://dust-aid.com/dust-shield/
Jun 26, 2015 07:23:22 #
Boentgru
Loc: Boston, Massachusetts, USA
imagemeister wrote:
Like, for what ???
The writer seems to looking for an optically neutral cover for the body of his camera; to seal it while changing lenses.
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