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Photo Forum / Digital Photography / DSLR Cameras / August 2006D200 plus AF-S Nikkor ED 300mm f/2.8 DII IF
Hi experts, My wife just got this lens (a used one) for her D200. In the docs I read that it is recommended to always use a filter (that is to be inserted in a filter pocket). Why is this recommended ? What filter should be used for general and low light sports shots ? Thanks, -Michael Many people keep a UV or "Skylight" filter on their lenses to protect them from accidental damage. It's much cheaper to replace a filter than a lens, should something come in contact with, and scratch it. As an added bonus, these filters sometimes improve the photos you take, but be careful that the changes are what you want. > Hi experts, > [quoted text clipped - 10 lines] > > -Michael > Many people keep a UV or "Skylight" filter on their lenses to protect > them from accidental damage. It's much cheaper to replace a filter > than a lens, should something come in contact with, and scratch it. > As an added bonus, these filters sometimes improve the photos you > take, but be careful that the changes are what you want. This doesn't even remotely apply to this lens since all filters are placed in the body of the lens near the rear. Rita > Many people keep a UV or "Skylight" filter on their lenses to protect them > from accidental damage. It's much cheaper to replace a filter than a lens, > should something come in contact with, and scratch it. As an added bonus, > these filters sometimes improve the photos you take, but be careful that > the changes are what you want. Read what he wrote. The filter goes inside the lens, not on the front, so it is not going to protect anything. Further, it's the docs for the lens that say that it was designed to have a filter installed, i.e. the optical calculations were performed with the assumption that there would be an optically flat piece of glass in that location, so it's not a matter of what "many people" do but of what the lens designers intended. >> Hi experts, >> [quoted text clipped - 10 lines] >> >> -Michael  Signature--John to email, dial "usenet" and validate (was jclarke at eye bee em dot net) I assume the recommendation to always have a filter in the lens (in the slot) is to make sure it's not left open as to prevent dust from entering the camera. Tnx, Guido > > Many people keep a UV or "Skylight" filter on their lenses to protect them > > from accidental damage. It's much cheaper to replace a filter than a lens, [quoted text clipped - 23 lines] > >> > >> -Michael It does shut close without the filter glass. So the glass thickness seems to be important. -Michael > I assume the recommendation to always have a filter in the lens (in the > slot) is to make sure it's not left open as to prevent dust from entering > the camera. Why do you assume this? >> > Many people keep a UV or "Skylight" filter on their lenses to protect > them [quoted text clipped - 33 lines] >> to email, dial "usenet" and validate >> (was jclarke at eye bee em dot net) Signature--John to email, dial "usenet" and validate (was jclarke at eye bee em dot net) According to Guido Zijlstra <mail@guido-zijlstra.net>: > I assume the recommendation to always have a filter in the lens (in the > slot) is to make sure it's not left open as to prevent dust from entering > the camera. No -- its thickness and index of refraction are a part of the lens formulation. it will be less sharp with no filter in place, because it will not be the entire lens which was calculated in the original design. It does not have to *do* anything -- and it is apparently shipped new with a do-nothing filter in place just to keep the glass optical path the same as the original design. The photo (which is all that I have been able to examine) seems to show a very dust-tight cover over the access point for the filter. I suspect that it will have an O-ring helping to seal it. Enjoy, DoN. SignatureEmail: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- > According to Guido Zijlstra <mail@guido-zijlstra.net>: > > I assume the recommendation to always have a filter in the lens (in the > > slot) is to make sure it's not left open as to prevent dust from entering > > the camera. > No -- its thickness and index of refraction are a part of the > lens formulation. it will be less sharp with no filter in place, > because it will not be the entire lens which was calculated in the > original design. Why would someone design a lens with the assumption that there's going to be a do-nothing piece of glass in the optical path, in addition to all the lens elements that actually do do something? Isn't that just needlessly complicated things? If you're going to do that, why not design it with the assumption that there are going to be *two* do-nothing pieces of glass in the optical path? > Why would someone design a lens with the assumption that there's going to > be a do-nothing piece of glass in the optical path, in addition to all the > lens elements that actually do do something? To allow for it's replacement with a real filter. > Isn't that just needlessly > complicated things? If you're going to do that, why not design it with > the assumption that there are going to be *two* do-nothing pieces of glass > in the optical path? Why not ? In case someone indeed needs two filters... -Michael According to Brian Trosko <btrosko@panix.com>: > > According to Guido Zijlstra <mail@guido-zijlstra.net>: > > > I assume the recommendation to always have a filter in the lens (in the [quoted text clipped - 9 lines] > be a do-nothing piece of glass in the optical path, in addition to all the > lens elements that actually do do something? That is so you can replace the "do-nothing" piece of glass with one which does the filtering which *you* specifically need at a specific time -- thus adding the filtering without altering the formulation of the lens. Note that you *could* simply mount a filter on the front of the lens, but a quick calculation shows that a 300mm f2.8 would require a minimum active diameter of the filter of 107.14mm, and a practical diameter of probably something like 115 or 120mm to allow for the ring and the mounting threads or bayonet. Have you ever *priced* filters this large? And note that the size used in the lens' internal mount is precisely the size used on a "normal" Nikkor 50mm f1.4 or f1.8 lens, so you should be able to use filters which you already own. Nikon did this so you don't have to spend a secondary fortune for the filters for the lens which already cost you one fortune. :-) > Isn't that just needlessly > complicated things? If you're going to do that, why not design it with > the assumption that there are going to be *two* do-nothing pieces of glass > in the optical path? Because a secondary one would not serve any real purpose. This first one does serve a purpose -- and it saves you money while it is doing so. Another example of this sort of design is the 16mm f3.5 fisheye which I have. It has a built-in turret with four filters -- clear, yellow, orange, and red, IIRC. This lens is too small to have a drawer for the filter, and the needed filters are very small in diameter back there. And you could *not* mount a filter in front of the highly curved front element without cropping out the edges. Enjoy, DoN. SignatureEmail: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- >My wife just got this lens (a used one) for her D200. > >In the docs I read that it is recommended to always use a filter (that >is to be inserted in a filter pocket). > >Why is this recommended ? I can only guess they mean as protection for the front element. In which case you want to get a decent multicoated UV filter to leave on the front of the lense. Personally, I'm not clumsy or careless with my gear, so damage isn't a major concern, so I don't use protective filters. >What filter should be used for general and low light sports shots ? In my opinion, none. The only filters I use with any regularity are graduated neutral density (ND) and polarizers. For just about everything else, you can do an easier, faster, and better job editing the photo to get the results you want. > I can only guess they mean as protection for the front element. In which > case you want to get a decent multicoated UV filter to leave on the > front of the lense. That is what we do with the other lenses. But according to the docs, this one has a built-in protection front glass, supposedly a "cheap" glass that is easily replaced. -Michael According to Michael Schnell <mschnell_at_bschnell_dot_de@aol.com>: > Hi experts, > [quoted text clipped - 4 lines] > > Why is this recommended ? Since this filter appears to be in the optical path within the lens, probably between elements, the thickness of the glass is included in the optical computation to form the lens element shapes, and having no filter present would render the lens somewhat less sharp. > What filter should be used for general and low light sports shots ? Looking at the PDF data sheet for the lens, I find the following line: ====================================================================== Attachment size of filter holder: 52mm NC filter provided ====================================================================== So -- it presumably comes with a filter which does nothing except provide the needed thickness of glass, and I don't think that you would need to replace that with any other filter for your intended usage. Only if this filter has been lost (possible with a used lens) do you need to find a filter to replace it -- something along the lines of a skylight filter or something similar which will have essentially no effect on your digital images. Enjoy, DoN. SignatureEmail: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- It would be very expensive to buy a filter for the front of this lens because of the diameter. For this reason Nikon places a filter slot further back in the lens barrel requring a smaller diameter filter and they provide a filter holder to place this fitler into the light path. The lens is designed to work properly with the correct thickness of glass in the light path. That's why they suggest that a filter is installed. Images won't be as sharp without this filter.The filter size is 52mm. There should already be a filter installed as original equipment in the lens. If not you can find an inexpensive replacement from just about any phtoo store. A daylight or haze filter is the best bet, but for different purposes you can install whatever fitler you want. I'm assuming you received the lens holder with the lens. Hope this helps Don Harper The Edge Photography Studio Leesburg, Va. 20176 > Hi experts, > [quoted text clipped - 10 lines] > > -Michael > It would be very expensive to buy a filter for the front of this lens > because of the diameter. [quoted text clipped - 20 lines] > The Edge Photography Studio > Leesburg, Va. 20176 This is all correct (along with DoN. Nichols post). But be aware that the placement in the optical system could mean increased reflections if you use any filter. It is best to use multicoated filters. On my canon 500 f/4 L IS lens, which has a similar filter holder, the filter that came with the lens is so well coated that at first I couldn't even tell there was a piece of glass there at all! Most (all?) super telephotos from at least Canon and Nikon use the small filter in the lens. For a polarizer, I had to buy canon's special polarizer which has a thumb wheel on the outside in order to turn the polarizer in the tube. Roger >The lens is designed to work properly with the correct thickness of >glass in the light path. >That's why they suggest that a filter is installed. Images won't be as >sharp without this filter.The filter size is 52mm. Interesting. My 300/2.8 AIS came without a filter when I bought it 2nd hand. Even without a filter, it is very sharp wide open. (Of course designs may differ). SignatureThat was it. Done. The faulty Monk was turned out into the desert where it could believe what it liked, including the idea that it had been hard done by. It was allowed to keep its horse, since horses were so cheap to make. -- Douglas Adams in Dirk Gently's Holistic Detective Agency > *From:* Michael Schnell <mschnell_at_bschnell_dot_de@aol.com> > *Date:* Sun, 30 Jul 2006 22:30:59 +0200 [quoted text clipped - 13 lines] > > -Michael Lenses with rear filters need a filter in the slot because the lens was designed for it. Any light passing through the filter at an angle is refracted, and the rest of the lens is designed for this. So not having a filter in place can make the result slightly blurred. A UV or even plain glass filter will be fine. > Hi experts, > [quoted text clipped - 10 lines] > > -Michael No reason to use a filter unless you need one. What the instructions are implying that it is better to use a small filter in the filter holder at the rear of the lens than some enorumous filter on the front. Filters to fit the front of this lens are very expensive (100's of USD+). But, you only need one when you want one. You certainly don't want to use anything when shooting low light (with Digital with White Balance control). In the old days of film, then you might want to insert a color correction filter in here when shooting under flourescent, or mecury vapor lighiting. PS .. I am jealous.. OK.. I would love to have such a lens! SignatureJim <jen....not....home..remvdots...@....yahoo According to <Jim>: > > Hi experts, > > [quoted text clipped - 18 lines] > don't want to use anything when shooting low light (with Digital with > White Balance control). As several of us have already pointed out in this thread, the formulation of the lens *assumes* at least a clear piece of quality glass in this place (it is between elements of the lens, so its presence or absence makes a difference in the paths of the light rays, and the lens will be marginally less sharp without at least a plain piece of glass there when you don't need a filter otherwise. And ideally, such a plain piece of glass should have antireflection coatings. But they *supply* such a default non-filter with the lens. It is only a problem with a used unit, in which the original owner lost track of the original filter. But -- yes -- the reason that it is designed in there is to keep you from having to purchase those very expensive front filters -- and Nikon from having to make and dealers from having to stock them. And -- Nikon was kind enough to make the internal filter size the same as the filters which fit the default "normal" lens on 35mm full frame Nikons -- 52mm. So the odds are that you already have the necessary filters if you need them. > PS .. I am jealous.. OK.. I would love to have such a lens! As would I. Enjoy, DoN. SignatureEmail: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
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