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Thread: Tamron SP 300mm f2.8 LD IF

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    Default Tamron SP 300mm f2.8 LD IF


    Description
    This is a popular super-telephoto lens in Tamron's "Super Performance" (SP) line. The current model is the 360E (auto focus) and 360B (manual focus) and at the time of this writing they cost about US$2800 at B&H. Its "LD" designation means that it includes "low dispersion" glass elements. The "IF" designation means that it is an "internal focus" lens so the lens body is a fixed length and the front element does not rotate. The lens body is all metal and seems very rugged.

    Unfortunately, this lens is not available with a 4/3rds mount. To use it with a 4/3rds camera you must purchase the manual focus version with Tamron's universal Adaptall-2 mount. The Adaptall-2 mount does not connect directly to a camera. Rather, you add one of Tamron's Adaptall-to-camera adapters. In this case you must use their Adaptall-OM adapter and mount it to your 4/3rds camera via one of the OM-to-4/3rds adapters (like the Olympus MF-1).

    This lens has attracted recent attention as a possible "low-cost" alternative to the Zuiko Digital (ZD) 300mm f2.8 ED lens. The ZD lens is considered one of the finest available and it is priced accordingly (about US$6000 at B&H). Of course, you must give up any idea of automatic control with the Tamron 300mm. Since it is not a 4/3rds lens, you must operate your camera in either Manual or Aperture Priority mode, set the aperture manually on the lens, and focus manually. As such, it may be a poor choice for action shots that require rapid changes in focus (although an E-1 equipped with a third-party split-prism focusing screen can help quite a bit). Even still, I wouldn't recommend this lens if you plan to snap quick shots of birds in flight owing to its manual focus.

    This is a large and heavy lens. It includes a "palm holder" (visible in the first photo above) that connects to the built-in tripod mount to make it a little easier to shoot by hand. However, don't expect to shoot by hand for very much time unless you're a body builder. Besides, you will need to shoot at 1/600th second or faster in order to avoid motion blur unless you have very steady hands.

    Since this lens has been in production for quite a while, many used ones are available. Previous models can be purchased at a fraction of their new cost. For this test I purchased a used model 60B in excellent condition for US$489 on eBay.

    The big question is, how does it compare to a comparable ZD 4/3rds lens? Remember that all versions of this Tamron 300mm lens are designed for film cameras so its image circle is sized for a 35mm film frame. With a 4/3rds camera, only half that diameter is used and, as a result, you can expect the image to be slightly less bright compared to a lens that focuses all of its light onto a 4/3rds image sensor at the same f-stop.


    Specifications (model 60B )
    - Focal length (FL): 300mm
    - Angle of view (AOV): 8 degrees (4 degrees on a 4/3rds camera)
    - Aperture range: f2.8 to f32
    - Lens construction: 7 groups, 10 elements
    - Coating: BBAR multiple-layer coating
    - Minimum focus: 8.2 ft (2.5 m) from the focus plane
    - Filter size: 112mm (front), 43mm (rear)
    - Length without hood: 9 inches (225mm) with front filter
    - Length with hood: 12.75 inches (324mm)
    - Weight: 4.7 lbs (2.1 kg).

    The following photo shows the hood off the lens so you can see the lens by itself. I also removed the front 112mm Tamron "Normal" filter. Also shown are two teleconverters. The smaller is the 140F 1.4x teleconverter that normally ships with the lens. The larger is an SP 2x teleconverter that is also available. An SP 2x high-performance teleconverter (200F) also exists but I was unable to acquire one for these tests.

    All three of these teleconverters were designed by Tamron exclusively for this and their 500mm f8.0 mirror lens. They mount between the Adaptall-2 mount and the Adaptall-to-camera mount. That means you have to remove the Adaptall-OM adapter each time you want to add a teleconverter. It doesn't take very long to do so but it is annoying because it requires that you carefully align the aperture scale pins (the teleconverters each include a second aperture scale which displays the true aperture value with the teleconverter).


    The next photo shows the 43mm rear filter that mounts onto a sliding filter frame. A "normal" filter is provided with the lens and should always be installed unless it is replaced with one of several optional filters.



    Measurements
    My measurements are based on the Imatest system (version 1.6.3). The lens was mounted on a tripod and located an appropriate distance away from each of several precision test targets. All tests were performed with my Olympus E-1 with an MF-1 OM adapter and an RM-CB1 remote shutter release cable. My E-1 is outfitted with a Katz Eye Optics (KEO) split-prism focusing screen and an HLD-2 battery grip. The mirror was locked up (anti-shock mode) for each shot.

    During the sharpness tests the lens had to be located a sizeable distance from the test target. Since I tested several lenses on the same day (some with focal lengths as high as 1000mm with teleconverters) it was necessary to perform these tests outdoors. Fortunately, the sky was overcast, transforming the sun into a diffuse light source.

    Sharpness - The easiest way to measure the sharpness or resolution of a lens is with a camera. However, this makes the camera a part of the measurement. That means we are measuring the lens and camera together---the camera cannot be removed from the measurement. For this reason it would be best to use a camera whose image sensor has the highest available resolution. That's why PhotoZone uses an E-300 for its 4/3rds lens measurements. I don't have an E-300 or E-500 (both 8 megapixel cameras) so I used my trusty E-1 (a 5 megapixel camera). Therefore the values I measured will not be the highest possible.

    Fortunately, this should not present a problem because we are not making absolute measurements of the lens' optical resolution. What we are doing is making relative measurements where we compare one lens to another on the same camera. I chose to use my award-winning ZD 150mm f2.0 ED lens for these comparisons because: (1) it is recognized as a very high quality, high resolution lens, (2) it should be comparable in quality to the ZD 300mm f2.8 ED lens and (3) it is the best telephoto lens that I own.

    There are several measures of image sharpness and before we can compare results, we have to make sure that we use the same measure. I chose to measure MTF50 in lw/ph. The MTF50 is the "modulation transfer function" or spatial frequency where the contrast drops to half (50%) of its low-frequency value. I know that sounds technical and you don't need to understand it because as long as you read my tests, I'll always measure the same thing so we can compare "apples to apples". But readers of my review should not compare my results to those of another reviewer unless they first make certain that they measured MTF50 also. As for "lw/ph", it is the units and it means line widths per picture height. Lw/ph is calculated as follows: lw/ph = 2 x lp/mm x picture height. Where lp/mm is the number of line pairs per millimeter and the picture height is also in millimeters. I won't bore you with any more technobabble. Suffice it to say that if you want to compare someone else's sharpness measurements to mine, they need to measure MTF50 in lw/ph using an E-1 camera. For more information about measurements, see Imatest.

    I measured the sharpness of the Tamron 300mm at each full f-stop. Here are the results:


    Notice that I made two measurements at each f-stop. First, I measured the sharpness in the center of the field of view (FOV). Second, I measured the sharpness in one of the corners of the FOV (I used the lower left corner). That way you can see whether a lens is sharper in the center or at a corner.

    Let's begin at the left end of the graph. Notice the severe drop-off at f2.8. This lens obviously gets pretty soft when its aperture is wide open. But what do the numbers mean in practical terms? An MTF50 less than 1000 lw/ph should be considered "bad" or "poor" because it will produce a very soft picture with low contrast. You need at least 1150 lw/ph before the picture begins to look "good" and I'd rather see 1450 lw/ph or more. But remember that many lenses, even good "pro" lenses, suffer from a loss in sharpness when the aperture is fully open.

    Now, let's move to the right end of the graph. All lenses, no matter how wonderful their glass is, will begin to lose sharpness at small apertures (high f-stops) because of diffraction as the light passes through the small iris in the lens. So the roll-off that begins at about f11 and gets worse as the aperture closes to f32 is fairly normal. This will be obvious when we compare it to a ZD lens shortly.

    Next, I wanted to see what effect Tamron's large 112mm front "normal" filter would have on the sharpness. I repeated three of the measurements with the filter on. This is shown below:


    I didn't expect there to be a significant difference but I was surprised to see that the presence of the filter increased the sharpness quite a bit when the aperture was wide open (f2.8). Personally, I wouldn't want to use this lens below f4.0. But if I did, I certainly would use the filter. Besides, it also protects the front lens element.

    Now, the moment we've all been waiting for... How does the Tamron 300mm f2.8 compare to the ZD 150mm f2.0? The next graph shows:


    Here's the same comparison again only I used a line graph instead of a bar graph. I also added a line to include the sharpness of the Tamron lens at f2.8 with the front filter.


    Notice tha amazingly strong sharpness of the ZD 150mm all the way down to f2.0. That is phenomenal. See my second ZD 150mm review for all of my test results. There's no way that the Tamron lens can approach the sharpness of the ZD lens below f11. I'm sure the same would be true if I had a ZD 300mm lens to measure also. But is the Tamron lens bad? I don't think so. Using a scale of poor-mediocre-okay-good-very good-excellent, I rate the sharpness of this lens between "poor" and "mediocre" below f4.0, between "okay" and "good" from f4.0 to f11, and gradually sinking toward "poor" at f32.

    Next, let's see what the Tamron 140F 1.4x teleconverter does to the sharpness. The next graph repeats all of the previous measurements with the 140F installed. Note, the front filter was left off for all of the following measurements so you can assume that the sharpness with a wide-open aperture will be a bit better if the filter is used.


    Notice that you loose one f-stop whenever you add a 1.4x teleconverter. That means that the aperture range of the lens will shift up to f4.0 to f45 when the 140F is installed.

    Next, I swapped the 140F for the SP 2x teleconverter. A 2x teleconverter eats two f-stops so the lens now has a range of f5.6 to f64.


    The last teleconverter I tried was the Olympus Digital EC-14, also a 1.4x tele. It produced results similar to the 140F as shown below:


    Finally, the next graph compares all three teleconverters. The bottom line: The 140F looks pretty good. As long as you use it in the middle of its range, you shouldn't need to be concerned about losing significant sharpness. The EC-14 was a pleasant surprise---it was almost as good as the 140F even though it is not optimized for the lens like the 140F is. Sadly, the SP 2x does not look so great. I think I would avoid it. Although, if you use it in the middle of its range, say around f16, it won't reduce the lens sharpness significantly. However, by f16 you're beginning to suffer from diffraction through the aperture so the sharpness is not that great to begin with.


    Chromatic Aberration (CA) - This test measures color fringing. I measured CA every time that I measured sharpness. It stayed below 0.5 pixels which is considered "insignificant". Overall, this Tamron 300mm lens appears to have no CA problems on my E-1. This is probably due in part to the fact that the small image sensor of a 4/3rds camera is only using the center half of the lens where CA is naturally the lowest. Remember also that this lens contains some LD elements which help reduce CA.

    Distortion - This test measures whether or not parts of the image are bent, stretched or squished. An extreme example would be the barrel distortion that is common to some wide-angle lenses like a "fisheye" lens. To measure it, a grid pattern of equally spaced horizontal and vertical lines are photographed and measured. This Tamron 300mm lens is basically free of distortion by itself or when it is used with a Tamron teleconverter. The highest deviation I measured was 0.112% which is very small. The distortion was noticeably higher when the lens was used with the Olympus EC-14 teleconverter. However, the highest deviation was -0.947% which is still modest.

    Vignetting - This test measures the light drop-off near the corners of the picture. I used worse-case conditions with the lens focused to infinity. The lens exhibited very little vignetting---no more than -0.371 f-stops (or EV). Most of the time it was less than -0.1 f-stops which is quite good. As with the low CA, the low vignetting is probably due to the fact that only the center half of the lens is being used on a 4/3rds camera and most vignetting, if it exists, probably occurs outside this area closer to the edge of the lens image circle.


    Conclusions
    Pros - This is a well-made super-telephoto lens with a strong metal body, low CA, low distortion and low vignetting. It accepts both front and rear filters. The small size of the rear filters can save money. It often includes a nice 1.4x teleconverter. It has several nice features, like a focus detente that the user can set, a built-in rotating tripod mount, large hood, palm rest, case and the body is an olive green color so the lens easily blends into outdoor surroundings.

    Cons - Since it is not a 4/3rds lens, it must be manually focused, the aperture must be manually set, and you cannot use the Program or Shutter Priority modes of your camera. The sharpness is okay but it is not that great---a super high-grade 4/3rds ZD lens is much sharper. You have to carry the weight of a large-aperture f2.8 lens yet you can't use f2.8 if you want sharp pictures. The lens is not weatherproof.

    On balance, I think this lens manages to barely earn a "good" rating.


    Copyright © 2006 by Harris Technologies, Inc. All rights reserved.
    Best regards, FL

    Pursuing excellence...

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    Default Re:Tamron SP 300mm f2.8 LD IF

    Thanks First Light,

    for an excellent Review!

    I am certainly looking forward to see the other ones that you have in the pipeline.

    All the best, Jens.

    PS. Should we ask questions and comment on your review and measurements here or in the discussion forum?
    Motto: Wildlife won't come to me unless I go to it.
    --------------------------------------------------------
    My Wildlife Photos: jensbirch.smugmug.com

    E-5, E-3, E-510, IR-E-1 ,E-P2
    ZD: 7-14, 14-54, 50, 50-200 SWD, 90-250/2.8, 300/2.8, EC-14, EC-20
    Peleng 8mm fisheye, shift Tamron SP 17/3.5, Tokina AT-X 300/2.8
    FL-50R, FL-40, FL-20, HLD-2, HLD-4, cleaved ZD EX-25 w. electric bypass, 250D, 500D, KatzEye Plus OptiBrite
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    Default Re: Tamron SP 300mm f2.8 LD IF

    Fantastic review. I have one of these lenses, and I am a little supprised at how much it drops off wide open, I didn't think it was that much.

    Cheers
    Wazza

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    Default Re: Tamron SP 300mm f2.8 LD IF

    Anyone know why using the normal front filter would sharpen up this lens at f/2.8 so significantly?

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    Default Re: Tamron SP 300mm f2.8 LD IF

    Can the E-1 provide focus confirmation with the Tamron lenses? I have a 400mm SP/F4 I want to use with my E-1. I had used it previously on a Nikon F-100 and that camera did provide focus confirmation.

    Thanks

    Peter

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    Default Re: Tamron SP 300mm f2.8 LD IF

    Quote Originally Posted by refiningman
    Can the E-1 provide focus confirmation with the Tamron lenses? I have a 400mm SP/F4 I want to use with my E-1. I had used it previously on a Nikon F-100 and that camera did provide focus confirmation.
    Nay, there is no focus confirmation with adapted lenses on the E-1.

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    Default Re: Tamron SP 300mm f2.8 LD IF

    Well, that's a pity but not a show stopper.

    Thanks

    Peter

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    Default Re: Tamron SP 300mm f2.8 LD IF

    Quote Originally Posted by refiningman
    Well, that's a pity but not a show stopper.
    Yah, when the alternative is dropping thousands on the AF lens or in the case of a 400mm 4/3rds lens, doing without, you find a way to make do.

    I've been experimenting with street shooting with my "manual tuna", the Tamron 300/2.8 reviewed above. At a bit over 5 pounds it'll bend your arm for sure, but it's light enough for me to handhold. I still need practice manual focusing, however I'm starting to get keepers if the subjects aren't moving too much.


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    Default Re: Tamron SP 300mm f2.8 LD IF

    Regards the query as to why a front filter improves image - this is a slight misinterpretation -

    Most "Ultra" telephoto lenses that have a drop in rear filter system were designed with the filter as part of the otical formula/set up, if you try using the lens without any filter in the filter holder the image degrades

    Front mounting filter should make little difference to lens performance and is there to protect the expensive front element lens.

    So the important filter is the rear drop in filter

    Mike
    Mike Smith

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    Default Re: Tamron SP 300mm f2.8 LD IF

    Quote Originally Posted by Mike_Smith_UK
    Regards the query as to why a front filter improves image - this is a slight misinterpretation -

    Most "Ultra" telephoto lenses that have a drop in rear filter system were designed with the filter as part of the otical formula/set up, if you try using the lens without any filter in the filter holder the image degrades

    Front mounting filter should make little difference to lens performance and is there to protect the expensive front element lens.

    So the important filter is the rear drop in filter
    Hi Mike,

    It seems that you haven't read my review. The rear filter was not in question. The standard factory "normal" rear filter was installed during all of my tests. The front filter caused the difference.

    Here's a summary of the front-filter observation: There are some who believe that any front filter will degrade the sharpness of a lens. They argue that photographers should never use "protection" filters. So I decided that every time I test a lens, I will test it with and without a front high-quality UV filter to test this idea. When I tested two Zuiko Digital lenses (50mm f2.0 macro and 150mm f2.0) I observed no significant difference. However, when I tested several legacy lenses (including the one in the above review) I was surprised to observe the opposite effect. In each case, the front "normal" filter of the legacy lens improved the sharpness at wide apertures (if the lens had a fixed, aperture it also improved the sharpness). Needless to say, I re-tested the lenses and triple-checked my results to make sure that I hadn't made a mistake because I did not expect this result. It runs contrary to expectations. However, my results were verified. I can't explain why the front filter had this effect on legacy lenses and that's why this discussion ensued.
    Best regards, FL

    Pursuing excellence...

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    Default Re: Tamron SP 300mm f2.8 LD IF

    Quote Originally Posted by First Light
    Hi Mike,
    There are some who believe that any front filter will degrade the sharpness of a lens.
    I was (am?) that kind of user.

    They argue that photographers should never use "protection" filters. So I decided that every time I test a lens, I will test it with and without a front high-quality UV filter to test this idea.
    thank you very much for that!

    When I tested two Zuiko Digital lenses (50mm f2.0 macro and 150mm f2.0) I observed no significant difference.
    I would expect something like that.

    However, when I tested several legacy lenses (including the one in the above review) I was surprised to observe the opposite effect.
    I am as well!


    In each case, the front "normal" filter of the legacy lens improved the sharpness at wide apertures (if the lens had a fixed, aperture it also improved the sharpness). Needless to say, I re-tested the lenses and triple-checked my results to make sure that I hadn't made a mistake because I did not expect this result. It runs contrary to expectations. However, my results were verified. I can't explain why the front filter had this effect on legacy lenses and that's why this discussion ensued.
    Is it possible that your high quality filter (I suppose B+W?) simply has better coating then the lens front element, thus reducing flare, and improving contrast. With contrast improvement resolution will be also improved?

    Yours Bojan

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    Default Re: Tamron SP 300mm f2.8 LD IF

    Quote Originally Posted by Bojan Volcansek
    Is it possible that your high quality filter (I suppose B+W?) simply has better coating then the lens front element, thus reducing flare, and improving contrast. With contrast improvement resolution will be also improved?
    I'm hesitant to say that the legacy lenses, themselves, had inferior coatings. Both of the Tamron lenses that I tested were from their high-end "SP" series and the front elements were multi-coated. In their documentation Tamron made a big deal about how great their coatings were. In both cases, the front filter was made by the lens manufacturer. They were originally an optional purchase (the front filters were not a standard part of the lens).

    I view the results similarly to you. I suspect that the filters reduced some of the stray reflections in the lens that otherwise would have reduced the contrast and therefore the sharpness.
    Best regards, FL

    Pursuing excellence...

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    Default Re: Tamron SP 300mm f2.8 LD IF

    Hello all,

    Front protective filters, in many cases, can cause an increase in lens resolution and, more importantly, a significant increase in contrast. Keep in mind that this is true ONLY if the protective filter features coatings (preferably multi-coatings) to minimize additional internal reflections off of the flat filter glass AND if the filter's glass substrate has been polished to true optical quality tolerances.

    Here is why the Tamron (and other similar very fast telephotos) will see an increase in resolution and contrast when using a high quality protective filter such as a 1A, UV or 1B filter:

    These filters chop off the deep blue and/or the UV portion of the spectrum. All lenses are corrected for visual wavelengths, usually with the correction being optimized for the yellow-green portion of the spectrum. Virtually all lenses have poorer correction in the red and particularly in the deep blue to violet regions of the spectrum. The result is slight color fringing with (usually) the blue fringing being the worst both from an optical and visual standpoint. When you use one of the protective filters previously mentioned, you effectively block the deep blue/violet regions of the spectrum to a fair degree. Thus the blue/violet color fringing is significantly reduced. The result is a slight to moderate increase in resolution and sometimes a very significant increase in contrast (apparent sharpness). Remember, contrast determines how clearly the lens resolves details at a given modulation, say, 30 lines per millimeter on the film plane.

    Another test which every photographer should perform on any telephoto lens which features rear "drop-in" filters is to test the lens both with and without the rear filter. The reason is that some lenses are sharper with the filter while others are sharper without it. It has nothing to do with the quality of the filter, but rather has to do with the optical designer's choice of whether to optimize the lens for use either with or without a rear filter. You see, the problem is that any rear filter introduces spherical aberration. The amount of spherical aberration which is introduced depends on the thickness of the filter, the focal length of the lens, and the shooting aperture. Thick filters increase the amount of spherical aberration, and very fast apertures also increase the amount of spherical aberration.

    So there you have it! The optical designer has to decide whether to optimize the lens for use without a rear filter, or the optical designer has to decide to optimize the lens for use with a specific thickness rear filter. The only way to determine the optical designer's choice is to test your lens both with and without the OEM supplied rear filter.

    I'll bet (since Tamron's earlier 107B SP 300 F/2.8 was optimized for use without any rear filter) that the camoflage green model 60B version will also test out to have about a 5% increase in sharpness and a 25% increase in contrast without the rear filter at maximum aperture. These are the results which I got with my original model 107B SP 300 F/2.8. Using a 1A 112mm front filter on my lens further boosted contrast by another 10% at maximum aperture.

    Here is my link about understanding resolution, contrast and MTF charts:

    http://www.adaptall-2.com/articles/R..._Contrast.html

    Hopefully the above link will be helpful.

    -- Michael

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    Default Re: Tamron SP 300mm f2.8 LD IF

    Hi Michael,

    Thanks for the excellent post! If I ever test another lens with a rear filter I'll do as you suggest and test it with and without. My impression was that the lens I tested was designed for the rear filter to be present and that's why I didn't try it without. Plus I was testing several lenses and it took way longer than I expected. I still haven't written all the reviews from my tests.

    I have a couple of thoughts about the soft UV explanation. First, one of the arguments that the anti-filter crowd use is that many digital SLRs reject most UV light and therefore a UV filter is not needed like it is for a film camera. If this is true, then the UV softness may not be very significant to many dSLR camera whether or not a UV filter is used.

    Second, the increased contrast provided by the UV filter for a lens with a varilable size aperture was exclusively at the wide end. Why didn't it improve the contrast at all apertures?

    In spite of these questions, I think your explanation is the best so far. Perhaps we'll discover that there are multiple things at work here.
    Best regards, FL

    Pursuing excellence...

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    Default Re: Tamron SP 300mm f2.8 LD IF

    Hello First Light,

    You are right! Most digital SLRs have an internal coating or coatings to reject UV. Two or more UV rejection coatings may be used, producing a steeper roll-off and usually will do a better job of rejecting UV. The question is, where in the very deep blue portion of the spectrum should the anti-UV coating begin to block light? UV rejection coatings which "turn on" in the very deep blue-violet still let some UV light get through. On the other hand UV rejection coatings which "turn on" in the deep blue do a better job of rejecting UV but can cause a degradation in color balance and saturation for deep blue and violet colors.

    The addition of a front UV filter cuts out more UV and cuts out a bit more of the deep blue. This can significantly reduce any deep blue fringing which is inherent in the lens.

    Thats a really good question regarding why a UV filter improved contrast at the wide aperture settings but not at the smaller aperture settings. Your question deserves a thorough explanation:

    The reason is that lenses are only corrected for specific wavelengths. At other wavelengths, a lens will have an inherent focus shift combined with slight spherical aberration. Virtually all lenses have a slight focus shift in the deep blue and exhibit slight spherical aberration for these wavelengths as well. The addition of the front UV filter effectively blocked some of the deep blue and increased the blocking of UV as well.

    Spherical aberration is non-linear with regards to aperture. Spherical aberration is halved each time you stop the lens down by a full f/stop. Stop your lens down by two full f/stops, and you reduce spherical aberration to 1/4 of original value. This explains why you saw an increase in contrast with the front UV filter at wider apertures but didn't see any real change in contrast at smaller apertures.

    This is another really good reason why a quality multi-coated front UV filter should be used on all lenses.

    Sincerest Regards,

    -- Michael

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    Default Re: Tamron SP 300mm f2.8 LD IF

    Thank you.!! Some of us live in the past and love old things. We need to realize that technology has improved so much that we can get a much better lens now with the same amount of money. Thanks again.
    ================================================

    Well, this review is being updated 8 days after I wrote it because I bought the Tammy sd 300mm f2.8 and I got it brand new (almost), not from the newpaper guys or the war correspondents. I got it with the 1.4 TC, the owner sold the 2x tc separately before I purchased the lens. In any case, I do not abuse a lens more than 1.4 times its focal lenght. This lens is a blessing well worth the money. Yes, I paid $950 for the lens with the 1.4 adapter, just because it was almost brand new. Just beware that there are many copies for sale around that are missing original 43mm filters (a must needed part of the optics), someothers have fungae, others have a loose collar mount, others have cracks on the front element. Also, the adapters are being subject to the law of demand and prices are going over the roof. Well, as I said before below, I belong to another cult (Pentax), so I appreciate the review and will come back from time to time to provide info on my experience with this beautiful lens.
    ================
    Well, I have used the lens with and without the front filter. I do not notice an improvement with the filter (in fact, it may be sharper without it), but I also found the lens being very sharp at the f2.8. If fact, I am very impressed with the sharpness that I only use it in that aperture. I also use the 43mm Tamron filter. That goes to say that every copy of the lens may be different and may have been subjected to different treatment. My lens is about 20 years old, but it was bought new in the box (old stock) two years ago. I purchased it recently. I also use the lens with the 1.4x converter that came with it and the quality is impressive. I get 420mm at f4. To avoid switching back and forth, I use the lens without the 1,4x adapter provided. I use the Pentax 1.7 AFA, that makes the lens AF.
    ==========================
    Well, since this is the only real technical review of this lens and the only source of information for those searching information prior to buy this lens, I will continue to update on my impressions on the Tamron SP 300mm f2.8. I had corresponded with Tamron about their 112mm normal filter and they assured that there was no special design on the filter. They suggested just a normal regular UV filter to physically protect the front element. The 43mm is definetly needed for a normal operation. The original review was done for the lens with certain camera. I am using this lens with a different camera, the Pentax Kx, so my review could complement the original review and it is based more on anecdotical experience than on mathematical tests, so take it at the face value. I did not notice impromement with the 112mm filter, in fact, the opposite may be true, but I would call it a tie. The lens is extremely sharp at f2.8, which was a surprise for me, I purchased the lens after reading the review here. The lens works well even at f22, after taht , I really do not like to use it. Once I place the Tamron Adaptall 2 1.4x TC to the lens, I get 420mm f4, the lens behaves well, but does no have the same IQ as without the TC. I proabably use it mostly within the f4 and f11. I photoshoot birds and have to use a shutter speed of 1/500 or higher. Installing this 1.4tc is a job (not hard, just cumbersome because the extra step), so I am using it without the Tamron 1.4xtc, but with the Pentax -F 1.7x AF TC, which provides AF for this manual lens (my converter is from Tamron to Pentax KA). You have to pre-focus, that is, you estimate the distance and set it roughly on the focus ring. The Pentax 1.7xTC takes care of the rest. This lens is heavy, over four pounds, almost five pounds with the camera. However, I use it handheld and have to take breaks often. My best photos have been taken with the lens without any TC, just with the adapter (KA) to the camera, which gives me manual focus but the camera reads all the information from the lens, so I do not have to stop it down. As I said before, my lens has very little use and has been treated very nicely. I have seen some lenses like this for sale, but they have seen some battles or wars and show the scarves. They may be OK inside, but who knows? My lens is a keeper and I wish you luck finding yours.
    ====================
    Hello again. I am updating this review to make sure all things I learn are posted. I found that the 43mm internal filter provided with the lens is Multi-coated. The 112mm front filter I have used is not MC, so that could explain the no difference. However, I will be testing again with the 112 mm MC filter to see the difference. In any case, if you can buy this lens, GET IT. It is good.
    ----------------------------------
    Well, this is my weekly review. I bought another lens like this fom Ebay for $600 US dollars. Big dissapointment. Bad IQ, the few spots here and there the seller mentioned were a problem. This lens has been dropped (I think) , it is hard to get a focussed image. Be careful what you buy on ebay. In the meantime, my mint copy works perfectly. I have the Pentax 1.7x adapter to make it AF (only if you prefocus first. i am getting best results manually focussing without any adapter. To use a polarizer on the front lens, you have to remove the hood, focus, set the linear polarizer (not cpl) and then place the hood back on. See you next week.
    Last edited by Idilio; 04-04-2011 at 09:15 PM. Reason: Update review

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    Default Re: Tamron SP 300mm f2.8 LD IF

    I now realize this forum if for Olympus(?), I am usually a Pentax and Canon guy. I will come back from time to time. I met someone with a 4/3 camera and his photos were spectacular.

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    Default Re: Tamron SP 300mm f2.8 LD IF

    (Photos were deleted - They were the wrong ones)
    Last edited by Idilio; 04-10-2011 at 12:57 PM. Reason: Posted wrong photos

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    Default Re: Tamron SP 300mm f2.8 LD IF

    Quote Originally Posted by Idilio View Post
    Here is a sample photo taken with the mint Tammy:

    Are you sure that's the picture you want to represent the Tam 300's capabilities?

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    Default Re: Tamron SP 300mm f2.8 LD IF

    Not really, it is a crop of a very distant shot. thanks for the advice. I will remove it. I will come back with another one, but I have problem with the size and have to crop it too much.

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    Default Re: Tamron SP 300mm f2.8 LD IF

    Here are some samples of the photos I have taken with the Tammy 300mm:
    http://www.pentaxforums.com/forums/m...00mm-f2-8.html

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    Default Re: Tamron SP 300mm f2.8 LD IF

    Here I've got sample of mine,
    open wide, but lack of CA and PF


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    Default Re: Tamron SP 300mm f2.8 LD IF

    Quote Originally Posted by naughty_boy View Post
    Here I've got sample of mine,
    open wide, but lack of CA and PF

    I saw this or a similar photo at the Pentax Gallery.

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