Polarizing filter for Sigma 150-600mm lens.
Jul 12, 2020 08:10:42 #
Why even use a polarizer with a 150-600? But that is a discussion in itself.
Jul 12, 2020 08:18:44 #
I bought this ne filter where I couldn’t get a right pics and one of the old photographer store up it in a special Maschine where I got told the lens had production errors. Sun pal gave me a new filter
Jul 12, 2020 09:40:12 #
I use to own the Sigma 150-600mm (C) via MC-11 on my Sony a7Riii and a7iii. I had a similar problem i n focus. I had a cheap CPL and just quit using it on that lens. If I had the money I would have tried a traditional polarizer. Although I have had no problems with that filter on other lenses. It is possible the glass chemistry doesn't like polarized light.
Jul 12, 2020 10:33:32 #
Sometimes it is basic simple things no one mentioned. Whether you have VR on or off while on your tripod. As someone else mentioned using a polarize lens on a lens with this much reach can be a problem reducing light.
Jul 12, 2020 10:43:57 #
Jul 12, 2020 10:52:32 #
olemikey
Loc: 6 mile creek, Spacecoast Florida
travisdeland wrote:
I bet your camera does not autofocus at f/8. You said you were using AF. If the lens is at full extension, and you add a CPL, you are probably over f/8. Which camera body are you using. The lens is f/5-6.3.
Concur, camera AF is probably calling home for help!!!
Jul 12, 2020 10:54:57 #
Strodav
Loc: Houston, Tx
travisdeland wrote:
I bet your camera does not autofocus at f/8. You said you were using AF. If the lens is at full extension, and you add a CPL, you are probably over f/8. Which camera body are you using. The lens is f/5-6.3.
Check your display to make sure you are at an f stop at or below your bodies spec. My Nikon dslr bodies AF down to f/8, but only near the center of the frame. Also check your AF indicator on your display to make sure it is locking.
Jul 12, 2020 10:57:19 #
As I indicated before, we needed more info. The fact that the camera is a crop sensor and that a tripod was used is a start. What focal length was used? As for other lenses, that info can tie into max apertures available. IS being in use or not is another factor. Until we know all the variables, we are just speculating. All said, I’d still go with the aperture too small for the AF to function properly.
Jul 12, 2020 11:08:59 #
dlmorris
Loc: Loma Linda, Ca
I'm just wondering, what happens if you focus it by hand? Use a tripod, turn off any lens stabilization, and see what happens. That will tell you if it is the filter or the autofocus....
Jul 12, 2020 11:15:22 #
Jul 12, 2020 11:51:21 #
I have stayed away from adding polarizing to that lens and use LRR, Photoshop & DXO - to make any necessary adjustments - enjoy
Jul 12, 2020 13:25:13 #
amfoto1
Loc: San Jose, Calif. USA
The Canon 80D is "f/8 capable". In most cases, this is only possible with the center AF point. Try restricting AF to only that point (set Single Point, then manually select the center point).
With a few specific lens/teleconverter combos, the 80D (and other models using the same 45-point AF system) are able to focus f/8 equivalent with as many as 27 AF points. AFAIK, this is only possible with Canon lenses and Canon teleconverters. Probably not with a Tamron lens.
Still, the AF system needs sufficient light to work. At 600mm the lens is f/6.3. A standard (rather dark) Circular Polarizer reduces light by at least 1.3 or 1.5 stops at it's weaker setting and will block as much as 2.3 or 2.5 stops worth of light at it's strongest setting (there's some variation brand to brand). So the effect of adding a polarizer to an f/6.3 lens may be like it were an f/11, f/14 or even f/16 in terms of the light reaching the camera, depending upon the filter type and how strongly its effect is dialed in. (In terms of how depth of field is rendered, the lens still acts like f/6.3). This can cause AF to slow down, hunt or fail... especially in challenging lighting conditions, where light levels and contrast are low, and with really distant subjects.
A possible solution is to use a "High Transmissive" Circular Polarizer. These are relatively new and only available from select providers. (I doubt Altura makes them... and don't know if Gobe, which are new, does or not.) "HT" C-Pol "cost" much less light lost to the filter. Typically it's only between .75 and 1.25 stops, depending upon the filter strength setting.
B+W "XS-Pro" and "F-Pro" Kaesemann Circular Polarizing filters are now both High Transmissive (their usually cheaper "MRC" filter is standard type). I know Heliopan and Hoya are also making High Transmissive C-Pols, too. There are likely some other brands making them.
I can't say why that filter is difficult to thread on. Gobe is a new brand of filters, budget priced but claiming high quality. I don't know what type of frame material they use. B+W and some other use brass frames to reduce galling and stuck filter issues. Works better than aluminum filter frames. Some manufacturers coat the threads on aluminum filters with Teflon to help prevent problems.
Also, is it a "slim" filter? Those are required for some wide angle lenses, to prevent vignetting problems. Slim filters with their narrow frames can be more difficult to thread onto lenses. Particularly in larger diameters, they also might be prone to flex or distort slightly, which will also make them difficult to thread onto the lens.
Some lenses now use plastic filter threads, which are less prone to filters getting stuck, might be somewhat "self healing", but also may be more easily damaged by a cross threaded filter. I don't know whether the Sigma lens uses metal or plastic threads. If it's metal, it's probably aluminum and a filter with aluminum frame would be more likely to be difficult to thread on, to gall, and to get stuck.
Like another response, I have to ask if you really need a C-Pol on that telephoto lens. I happen to have C-Pol to fit 100-400, 300mm and 500mm lenses in my kit... but very rarely use them. One of my 300mm and my 500mm use "drop in filters".... and from new I've had a drop-in C-Pol especially made for them. I bet I can count on my two hands the number of times I've actually used that in over fifteen years. It's probably about the same with my 100-400mm and two smaller 300mm that I use, all of which use 77mm filters. I just haven't made note of how often I use a C-Pol on them. All I can safely say is, "Not very often".
However, maybe I should use a C-Pol on my telephotos more often... For example, it would have reduced the reflections off the windshields and shown the drivers better in this image...
But other times, it's not a problem, as in this case...
Finally... some lenses simply don't "play well" with filters. I don't know about that Sigma. But I know the original Canon 100-400mm lens (push/pull zoom version) "goes soft" when any filter is installed on it. Even a very high quality, multi-coated filter tends to reduce that particular lens' image quality. A lot of users who had "protection" filters on their 100-400mm push/pull from new have been stunned to see how sharp it is when the filter is removed! I've only briefly used a loaned copy of that lens (I'm just not a fan of push/pull zooms... although I know some people love them). I do use the "II" version of it (now with separate zoom and focus rings) and see no significant effect from filters on the newer one. Don't ask me why that happened with the 100-400 push/pull. I have no idea. Just wanted to mention it as a possibility.
IMO, filter quality is critical. Much of the time I simply don't use a filter. When I do use one, more often than not it's a C-Pol... that's easily the most useful filter with digital. I also use some Neutral Density and UV (yes, the latter are for "protection", but I only install them when shooting in situations where they might actually serve a purpose). I ONLY buy high quality, multi-coated filters. Mostly I use B+W... MRC and F-Pro (8 layer multi-coated) and XS-Pro (16-layer "nano" multi-coated). B+W XS-Pro series are also "slim" filters (actually even their "standard" filters are pretty low profile and slim). I don't use B+W's lower cost "SC" or "single coated" filters. Those are probably fine indoors under controlled lighting, because they use the same top quality Schott glass and brass frames of the more advanced models. But most of my shooting is outdoors and sometimes in pretty challenging lighting, so I want multi-coated filters.
I use a few Hoya too. Some of their better ones are quite good. But they also make a lot of cheap, lower quality. Last I looked Hoya had at least 6 or 8 different C-Pol... most of which I wouldn't use. On the other hand, Hoya's top of the line "HD3" are very good, similar to B+W XS-Pro.... except the Hoya all use aluminum frames and those HD3 cost twice as much as the top of the line B+W!
Another thing just occurred to me... Are you certain the filters you got are CIRCULAR Polarizers? If they're linear polarizers, they will mess with AF and cause it to fail. If the filters are only marked "Pol" or "polarizer" or "PL", they're probably linear. A C-Pol is almost always labelled as such.
With a few specific lens/teleconverter combos, the 80D (and other models using the same 45-point AF system) are able to focus f/8 equivalent with as many as 27 AF points. AFAIK, this is only possible with Canon lenses and Canon teleconverters. Probably not with a Tamron lens.
Still, the AF system needs sufficient light to work. At 600mm the lens is f/6.3. A standard (rather dark) Circular Polarizer reduces light by at least 1.3 or 1.5 stops at it's weaker setting and will block as much as 2.3 or 2.5 stops worth of light at it's strongest setting (there's some variation brand to brand). So the effect of adding a polarizer to an f/6.3 lens may be like it were an f/11, f/14 or even f/16 in terms of the light reaching the camera, depending upon the filter type and how strongly its effect is dialed in. (In terms of how depth of field is rendered, the lens still acts like f/6.3). This can cause AF to slow down, hunt or fail... especially in challenging lighting conditions, where light levels and contrast are low, and with really distant subjects.
A possible solution is to use a "High Transmissive" Circular Polarizer. These are relatively new and only available from select providers. (I doubt Altura makes them... and don't know if Gobe, which are new, does or not.) "HT" C-Pol "cost" much less light lost to the filter. Typically it's only between .75 and 1.25 stops, depending upon the filter strength setting.
B+W "XS-Pro" and "F-Pro" Kaesemann Circular Polarizing filters are now both High Transmissive (their usually cheaper "MRC" filter is standard type). I know Heliopan and Hoya are also making High Transmissive C-Pols, too. There are likely some other brands making them.
I can't say why that filter is difficult to thread on. Gobe is a new brand of filters, budget priced but claiming high quality. I don't know what type of frame material they use. B+W and some other use brass frames to reduce galling and stuck filter issues. Works better than aluminum filter frames. Some manufacturers coat the threads on aluminum filters with Teflon to help prevent problems.
Also, is it a "slim" filter? Those are required for some wide angle lenses, to prevent vignetting problems. Slim filters with their narrow frames can be more difficult to thread onto lenses. Particularly in larger diameters, they also might be prone to flex or distort slightly, which will also make them difficult to thread onto the lens.
Some lenses now use plastic filter threads, which are less prone to filters getting stuck, might be somewhat "self healing", but also may be more easily damaged by a cross threaded filter. I don't know whether the Sigma lens uses metal or plastic threads. If it's metal, it's probably aluminum and a filter with aluminum frame would be more likely to be difficult to thread on, to gall, and to get stuck.
Like another response, I have to ask if you really need a C-Pol on that telephoto lens. I happen to have C-Pol to fit 100-400, 300mm and 500mm lenses in my kit... but very rarely use them. One of my 300mm and my 500mm use "drop in filters".... and from new I've had a drop-in C-Pol especially made for them. I bet I can count on my two hands the number of times I've actually used that in over fifteen years. It's probably about the same with my 100-400mm and two smaller 300mm that I use, all of which use 77mm filters. I just haven't made note of how often I use a C-Pol on them. All I can safely say is, "Not very often".
However, maybe I should use a C-Pol on my telephotos more often... For example, it would have reduced the reflections off the windshields and shown the drivers better in this image...
But other times, it's not a problem, as in this case...
Finally... some lenses simply don't "play well" with filters. I don't know about that Sigma. But I know the original Canon 100-400mm lens (push/pull zoom version) "goes soft" when any filter is installed on it. Even a very high quality, multi-coated filter tends to reduce that particular lens' image quality. A lot of users who had "protection" filters on their 100-400mm push/pull from new have been stunned to see how sharp it is when the filter is removed! I've only briefly used a loaned copy of that lens (I'm just not a fan of push/pull zooms... although I know some people love them). I do use the "II" version of it (now with separate zoom and focus rings) and see no significant effect from filters on the newer one. Don't ask me why that happened with the 100-400 push/pull. I have no idea. Just wanted to mention it as a possibility.
IMO, filter quality is critical. Much of the time I simply don't use a filter. When I do use one, more often than not it's a C-Pol... that's easily the most useful filter with digital. I also use some Neutral Density and UV (yes, the latter are for "protection", but I only install them when shooting in situations where they might actually serve a purpose). I ONLY buy high quality, multi-coated filters. Mostly I use B+W... MRC and F-Pro (8 layer multi-coated) and XS-Pro (16-layer "nano" multi-coated). B+W XS-Pro series are also "slim" filters (actually even their "standard" filters are pretty low profile and slim). I don't use B+W's lower cost "SC" or "single coated" filters. Those are probably fine indoors under controlled lighting, because they use the same top quality Schott glass and brass frames of the more advanced models. But most of my shooting is outdoors and sometimes in pretty challenging lighting, so I want multi-coated filters.
I use a few Hoya too. Some of their better ones are quite good. But they also make a lot of cheap, lower quality. Last I looked Hoya had at least 6 or 8 different C-Pol... most of which I wouldn't use. On the other hand, Hoya's top of the line "HD3" are very good, similar to B+W XS-Pro.... except the Hoya all use aluminum frames and those HD3 cost twice as much as the top of the line B+W!
Another thing just occurred to me... Are you certain the filters you got are CIRCULAR Polarizers? If they're linear polarizers, they will mess with AF and cause it to fail. If the filters are only marked "Pol" or "polarizer" or "PL", they're probably linear. A C-Pol is almost always labelled as such.
Jul 12, 2020 13:58:05 #
Alan,
Thank you for the comprehensive response. I took your (and others) advice and just ran a series of center-point focus tests with and without the CLP ranging from f6.3 to f29 at focal lengths of 200, 300, 400, 500, 600. It is sunny today so ISO was set at 100 or 200 as needed. I used my FoCal target in the back yard.
Shots without the CPL all look crisp. All of the CPL shots look blurry.
I like using the filter when doing nature photography at a local lake. Lots of water reflections.
The CPL on my Tamron 70-200mm works great at producing crisp shots and reducing glare.
As of now, I am resigned to not using a filter on the Sigma 150-600mm.
I appreciate all of the feedback. What a cool community with decades of experience!
Thank you for the comprehensive response. I took your (and others) advice and just ran a series of center-point focus tests with and without the CLP ranging from f6.3 to f29 at focal lengths of 200, 300, 400, 500, 600. It is sunny today so ISO was set at 100 or 200 as needed. I used my FoCal target in the back yard.
Shots without the CPL all look crisp. All of the CPL shots look blurry.
I like using the filter when doing nature photography at a local lake. Lots of water reflections.
The CPL on my Tamron 70-200mm works great at producing crisp shots and reducing glare.
As of now, I am resigned to not using a filter on the Sigma 150-600mm.
I appreciate all of the feedback. What a cool community with decades of experience!
Jul 12, 2020 14:26:00 #
This may be obvious, but make sure it is a circular polarizing filter, otherwise the autofocus will not work properly.
Jul 12, 2020 14:36:13 #
dlmorris
Loc: Loma Linda, Ca
Just curious, what is the difference between a circular polarizer and whatever other kind there is? Not to steal the thread, just wondering....
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