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 #1 Advice please on 200mm+ lenses Posted 01/04/2009 @ 19:27 |
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Took my 40-150mm lense to it's limit photographing wildlife in Sri Lanka, not everything will pose for a photo while you get closer enough, going back later this year. And plan on doing two day national park tour.
So after a lense around 200-400mm for example.
Any recommendations? Got my eye on a Sigma 135-400mm f4.5-5.6 DG APO which is around £400
As I use an Olympus (Four Thirds) it does limit the lenses. |
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Still Loving my Nidecker Platinum
Karl Goldsmith
Biofuels The Myths and Lies! Food Crisis - What a bloody surprise.
I Want Those Flashing Lights |
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| #2 Re: Advice please on 200mm+ lenses Posted 28/05/2009 @ 13:03 |
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| In reply to post #1
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A second body like the panasonic micro 4/3rds that has the electronic viewfinder will let you use practically any lens by using an adapter.
Plenty of adapters on ebay, although it will all be manual for obvious reasons.
There's plenty of nice manual 300+ lenses out there. |
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| #3 Re: Advice please on 200mm+ lenses Posted 28/05/2009 @ 13:14 |
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| In reply to post #1
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I don't know anything about that format.
If you can get the quality you need out of a zoom, then that's all good.
You may find that wide-range zooms are pretty poor at the limits of their range, especially the long end of a tele zoom.
Iff you're shooting wildlife then you don't generally want a zoom at all; you just need as much length as you can get. Most bird photogs will use a 300, 400, 500, or 600mm (35mm sizes) and a 1.4 or 2x convertor. 300mm is great for hand-holding and for things which aren't too far away; 600mm is about as much as you can deal with in practice. So a 300mm with a 2x is a common combo at 35mm.
None of this is a lot of use for snowboarding, although 300mm is good for shooting slalom racess if you don't want the background. |
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| #4 Re: Advice please on 200mm+ lenses Posted 29/05/2009 @ 13:28 |
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| In reply to post #3
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QUOTE (philw - 28/05/2009 @ 13:14) I don't know anything about that format. If you can get the quality you need out of a zoom, then that's all good. You may find that wide-range zooms are pretty poor at the limits of their range, especially the long end of a tele zoom. Iff you're shooting wildlife then you don't generally want a zoom at all; you just need as much length as you can get. Most bird photogs will use a 300, 400, 500, or 600mm (35mm sizes) and a 1.4 or 2x convertor. 300mm is great for hand-holding and for things which aren't too far away; 600mm is about as much as you can deal with in practice. So a 300mm with a 2x is a common combo at 35mm. None of this is a lot of use for snowboarding, although 300mm is good for shooting slalom racess if you don't want the background.
The equivalent 35mm is double the Two Thirds standard, so Sigma 135-400mm would be like using a 270 - 800mm lense on a 35mm.
Although as WillyPete said I am also looking at using an old lense with an adaptor. |
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Still Loving my Nidecker Platinum
Karl Goldsmith
Biofuels The Myths and Lies! Food Crisis - What a bloody surprise.
I Want Those Flashing Lights |
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Republic of Ireland |
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| #5 Re: Advice please on 200mm+ lenses Posted 29/05/2009 @ 20:21 |
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what are you looking to photograph?
if it's sports or things that require a fast shutter speed to freeze the action you need a lense which collects a lot of light (ie has a low f stop). a lot of convertors will reduce the effective f stop of the lense you are using.
i don't know too much about cameras, formats, specific products etc, but when researching to buy a relatively cheap superzoom (prosumer?) camera that was the advice given and it served me well. |
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| #6 Re: Advice please on 200mm+ lenses Posted 29/05/2009 @ 21:42 |
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| In reply to post #5
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QUOTE (rog-g - 29/05/2009 @ 20:21) a lot of convertors will reduce the effective f stop of the lense you are using.
They all must, if you think about what f-stop is.
Ok, it's focal length divided by the opening size, so as you can't increase the opening by sticking an extra bit of tube on it, double the focal length and you're going to double the f-stop... lose two stops of light. |
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| Posts: 444 |
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| #7 Re: Advice please on 200mm+ lenses Posted 30/05/2009 @ 10:22 |
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Revision #1 (Last edited: 30/05/2009 @ 10:23) |
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i have a raynox 2.2x convereter for my fz20. it does not reduce the f stop. it fits on the outer end of the lense (fixed lense) hence not the use of all. it does it by being big to collect more light. |
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| #8 Re: Advice please on 200mm+ lenses Posted 30/05/2009 @ 15:35 |
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QUOTE (rog-g - 30/05/2009 @ 10:22) i have a raynox 2.2x convereter for my fz20. it does not reduce the f stop. it fits on the outer end of the lense (fixed lense) hence not the use of all. it does it by being big to collect more light.
(sic)
You can't increase the diameter of the entrance pupil by sticking things on the front of the lens; the limitation is still there inside your lens. Hence increasing the focal length reduces the amount of light reaching the sensor.
It's simple to confirm by checking your exposure. If you don't know how to do that then stick the camera on manual, expose for the lens with the TC off, then stick it on and use the same settings.
If you do find you've got a convertor which doesn't reduce your aperture, then you've got an amazing product which photographers world wide will bite your hand off for  |
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| #9 Re: Advice please on 200mm+ lenses Posted 30/05/2009 @ 18:29 |
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Revision #1 (Last edited: 30/05/2009 @ 18:32) |
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QUOTE (philw - 30/05/2009 @ 15:35) If you do find you've got a convertor which doesn't reduce your aperture, then you've got an amazing product which photographers world wide will bite your hand off for
by adding a larger diameter lense to the front of an existing one the convertor does not reduce the f stop. perhaps try googling Raynox DCR2020 pro, and check to see whether it maintains the full aperture when fitted (my camera is a Lumix FZ20 and does indeed maintain a full f2.8 with the covertor fitted).
by being larger that the existing front lense the convertor does actually collect more light by virtue of it's area (parallel light waves arriving at a larger area at a preset luminous intensity = more photons collected). it then focusses this light on the existing front lense. this increased light intensity then allows the f stop to be maintained even at a higher zoom level than the original lense.
like i said in my first post, i'm not a photographic expert or anything, but that all seems relatively straight forward. |
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| #10 Re: Advice please on 200mm+ lenses Posted 03/06/2009 @ 12:44 |
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Negative.
The light is from a MUCH smaller field of view, so it is not the same amount of photons or anything.
If you can set the speed and aperture manually, then take a shot with just the regular lens, then a comparison shot at same speed and aperture, but with the tele mounted in a wider focal length so that the field of view matches then you will have a true test of whether you lose light or not. |
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| #11 Re: Advice please on 200mm+ lenses Posted 04/06/2009 @ 19:56 |
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| In reply to post #9
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QUOTE (rog-g - 30/05/2009 @ 18:29) (my camera is a Lumix FZ20 and does indeed maintain a full f2.8 with the covertor fitted).
Your camera is probably unaware that you put something in front of the lens, so the lens aperture reads the same as it does without the thing on the front. That doesn't affect the fact that you have a smaller field of view... |
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| #12 Re: Advice please on 200mm+ lenses Posted 04/06/2009 @ 23:52 |
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| In reply to post #11
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so according to the manufacturer:
"There will be no reduction of light value (F.Number) when this conversion lens is attached on the camera's lens."
http://www.raynox.co.jp/english/dcr/dcr2025pro/index.htm |
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| #13 Re: Advice please on 200mm+ lenses Posted 05/06/2009 @ 11:42 |
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QUOTE (rog-g - 04/06/2009 @ 23:52) so according to the manufacturer: "There will be no reduction of light value (F.Number) when this conversion lens is attached on the camera's lens." http://www.raynox.co.jp/english/dcr/dcr2025pro/index.htm
Nor does it imply the "increased intensity" of light reaching the sensor that you refer to a few posts up.
Remember, focal length is NOT a factor of actual lens length. |
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| Posts: 444 |
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| #14 Re: Advice please on 200mm+ lenses Posted 05/06/2009 @ 13:08 |
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Revision #1 (Last edited: 05/06/2009 @ 13:09) |
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like i have said i'm no expert. I'll just repeat what i said to start with.
some convertors will not reduce the f stop of the camera you're using.
this is not what you think, however when refered to manufacturers statements regarding this you seem to ignore it.
pete and phil, not being funny but i was trying to give a bit of advice, i guess you guys know best so i'll just shut up. |
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| #15 Re: Advice please on 200mm+ lenses Posted 05/06/2009 @ 18:34 |
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Revision #1 (Last edited: 05/06/2009 @ 18:35) |
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I think the manufacturer made a mistake, or more likely were mistranslated (see below). Or they have a special deal with the devil to get around the laws of physics.
You will of course still be able to set your your lens to its maximum aperture. That's completely unaffected by things you may fasten to the front of the lens. I think this is what the manufacturers are trying to say. The error's been copied and repeated across the internet, but there's no other source of this rather astounding fact.
But your wide-open lens sees a lower intensity of light, because of the reduced field of view of the longer focal-length lens. The f-number equation takes this into account... the number on the lens is unchanged, but the f-number of the combination is altered by a factor of 2.2. If you were manually exposing this would be obvious. On an auto camera the exposure system will simply compensate by reducing shutter speed or increasing ISO or both. |
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