What's a "fixed" 2.8 lens mean?
Nov 27, 2023 11:40:16 #
R.G. wrote:
Is that to say there are lenses whose maximum aperture varies as the distance to the focus point varies?
Don't think so. Thanks BE SAFE!!
Tom
Nov 27, 2023 17:20:56 #
foathog wrote:
Canon has a refurb RF 100MM fixed 2.8 macro lens for sale. What do they mean my fixed? Maybe I'm not up on new terminology. It wouldn't be the first time
Harry
Harry
A fixed lens, as in this case 2.8, is a Lense that the aperture does not change. You will need to change distance shutter speed or ISO to change the settings.
Nov 27, 2023 20:10:14 #
frankraney wrote:
A fixed lens, as in this case 2.8, is a Lense that the aperture does not change. You will need to change distance shutter speed or ISO to change the settings.
Really?
Nov 27, 2023 21:58:41 #
frankraney wrote:
A fixed lens, as in this case 2.8, is a Lense that the aperture does not change. You will need to change distance shutter speed or ISO to change the settings.
What does SHUTTER SPEED or ISO have to do with it???? Thanks BE SAFE!!
Tom
Nov 27, 2023 23:38:55 #
tshift wrote:
What does SHUTTER SPEED or ISO have to do with it???? Thanks BE SAFE!!
Tom
Tom
If you can't change the the aperture, because it's fixed,you have to change something else to change the.exposure
Nov 27, 2023 23:39:50 #
frankraney wrote:
If you can't change the shutter you have to change something else to change the.exposure
Like, perhaps, the lens aperture?
Nov 27, 2023 23:45:03 #
CHG_CANON wrote:
Like, perhaps, the lens aperture?
Thank you Paul, I meant aperture. Because it's fixed you can't change it
Nov 28, 2023 05:06:19 #
frankraney wrote:
Thank you Paul, I meant aperture. Because it's fixed you can't change it
My 200-500mm Nikon is f/5.6 fixed aperture. It will stay that all the way from 200 through 500mm. BUT if I so choose I can set up any aperture from F5.6 to f/32. Thanks BE SAE!!
Tom
Nov 28, 2023 07:46:18 #
Orphoto
Loc: Oregon
There is a 3rd type of fixed aperture germaine to prime macro lenses which has not yet been mentioned.
Ordinarily macro lenses shift their effective aperture as they reach higher magnifications. There have been some rather esoteric designs that keep the aperture constant, ie: fixed.
I have no idea whether the model in question has this.
Ordinarily macro lenses shift their effective aperture as they reach higher magnifications. There have been some rather esoteric designs that keep the aperture constant, ie: fixed.
I have no idea whether the model in question has this.
Nov 28, 2023 08:14:33 #
My RF 100 2.8 may be fixed at 2.8 but it does not deliver a consistent exposure throughout its focus range. As you move closer and focus closer to an object you must either open the aperture or slow the shutter speed to compensate. Similar to bellows extension factor with a view camera. Could this lens be consistent throughout its entire focus range? Perhaps that is what is implied.
Nov 28, 2023 08:26:49 #
Orphoto wrote:
There is a 3rd type of fixed aperture germaine to prime macro lenses which has not yet been mentioned.
Ordinarily macro lenses shift their effective aperture as they reach higher magnifications. There have been some rather esoteric designs that keep the aperture constant, ie: fixed.
Ordinarily macro lenses shift their effective aperture as they reach higher magnifications. There have been some rather esoteric designs that keep the aperture constant, ie: fixed.
When I bought my first Nikon I bought 3 lenses. One of those lenses is an "AF Micro Nikkor 105mm 1:28 D". I was going to return the lens because I thought it was defective. I did some reading and found that a shrinking, effective aperture, was normal for that lens.
Many, many years later I still love this lens.
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Nov 28, 2023 08:57:50 #
frankraney wrote:
Thank you Paul, I meant aperture. Because it's fixed you can't change it
But, it's not 'fixed' ... Choose any value you desire between f/2.8 and f/32, as extensively discussed in the many, many replies to this thread.
Nov 28, 2023 09:17:19 #
CHG_CANON wrote:
But, it's not 'fixed' ... Choose any value you desire between f/2.8 and f/32, as extensively discussed in the many, many replies to this thread.
Nobody reads anymore....
Nov 28, 2023 11:41:07 #
tshift wrote:
My 200-500mm Nikon is f/5.6 fixed aperture. It will stay that all the way from 200 through 500mm. BUT if I so choose I can set up any aperture from F5.6 to f/32. Thanks BE SAE!!
Tom
Tom
I did not know you could still change the aperture on a fixed lens that's a great feature.. I'll have to look at that lens I've been looking for a long lens anyway.
Nov 28, 2023 11:51:19 #
frankraney wrote:
I did not know you could still change the aperture on a fixed lens that's a great feature.. I'll have to look at that lens I've been looking for a long lens anyway.
There are some rare lenses where both the aperture and focal length are 'fixed' in a nonchangeable way. None of the lenses in Canon's 30+ years of EOS technology are any of these rarities. The author of the advertising text that caught the attention of the OP failed at their task, as did everyone else involved in reviewing and approving that error before publication.
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