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Old Aug 12, 2003, 9:41 AM   #1
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Default General question about lens/filter size and threads

Hey all

I have a few general questions about lenses, filters, and their mating threads.

I understand that due to focal lengths and lens design, not every lens of the same thread diameter is compatible with every camera it may physically screw on....... That being said.....

Question 1:
Are lenses (like add-on macros, telephotos, and wide angle lenses, not SLR lenses) with the same diameter threads (like 49mm or 55 mm) compatible in that they will screw in to eachother or do they have different thread-pitch eg. some with 1.0, 1.25, 1.75 etc.

AKA can I use a canon 55mm filter on an olympus 55mm thread end lens.... or if the focal length was right, could I use the same diameter Nikon macro or telephoto add-on lens on a Canon camera

Question 2:
Assuming the same thread dia and pitch, are there different adapters out there to compensate for the differences in focal length of a lens (aka some shorter, some longer) so that when I stack one on the end of my camera so I don't get severe distortion, CA, etc?

Thanks for the help

John
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Old Aug 12, 2003, 4:38 PM   #2
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Default Re: General question about lens/filter size and threads

Quote:
Originally Posted by JohnC
Question 1:
Are lenses (like add-on macros, telephotos, and wide angle lenses, not SLR lenses) with the same diameter threads (like 49mm or 55 mm) compatible in that they will screw in to eachother or do they have different thread-pitch eg. some with 1.0, 1.25, 1.75 etc.

AKA can I use a canon 55mm filter on an olympus 55mm thread end lens.... or if the focal length was right, could I use the same diameter Nikon macro or telephoto add-on lens on a Canon camera
The answer is generally a YES. You can use whatever filters on whatever lenses with an obvious exception of using a polarizer. Thicker polarizer mounted on a wide to ultra wide lens will cause vignetting. So, if you intend to use a polarizer on a wide or ultra wide lens, you can test before you buy to ensure no vignetting, or you buy a slim polarizer, or you buy large thread filter and a step-up ring.


Quote:
Originally Posted by JohnC
Question 2:
Assuming the same thread dia and pitch, are there different adapters out there to compensate for the differences in focal length of a lens (aka some shorter, some longer) so that when I stack one on the end of my camera so I don't get severe distortion, CA, etc?
What is "pitch"? Most filters are flat glass that will not induce distortion. Poorly made close-up lens do. There is no filter that can help reduce distortion, CA, etc. Filters are used to change or correct color/tonality, to do close-up, or to introduce special effects. If you will get severe distortion and CA, it is likely the fault of the camera lens.

Please take a look at the "Filters" section of my Coolpix 4500 user guide for the details.

CK
http://www.cs.mtu.edu/~shene/DigiCam
Nikon Coolpix 950/990/995/2500/4500 User Guide
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Old Aug 12, 2003, 8:54 PM   #3
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Hi JohnC and shene,
JohnC’s question about “pitch” is about the mechanical threads of screwing devices .

In imperial , thread is specified with OD and tpi (threads per inch) , for instance: ¼ -20 (coarse thread as camera tripod mount) , ¼-28 (fine thtread), etc ..

In metric , thread is specified with OD and “pitch” ( advance distance in 1 turn of the svrew) , for instance: M10, M12, etc … also available as coarse and fine thread.
http://www.efunda.com/DesignStandard...ewm_coarse.cfm
http://www.fullermetric.com/Dimensio...ad%20Chart.pdf

I thought threads pitch used in photos are unique for a given diameter, but I was wrong, the following link talk about some interesting history about this question:
http://www.skgrimes.com/ilex/measurex.htm



Anyway, nowadays, when you go buy a filter for your (not that old) camera, you have all the chance to get the right one by specifying only the diameter.
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Old Aug 16, 2003, 1:32 PM   #4
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Thanks

That answered most of my questions.

I knew with some old cameras, even when you had the same diameter lens, they used different thread pitch so you had to buy lenses and filters for those specific cameras from the manufacturers. I was hoping that was not the case with new camera filters.

The other question about vignetting with polarizer filters was also answered -- it sounds like wide angle lenses just need a bigger diameter filter so you don't catch the ring. Next question on that one is this:
How much bigger diameter does the filter need to be than the wide angle lens so you don't get vignetting? 2mm, 5mm, 10mm, etc?

Makes me wonder if that is the same thing that happens with tele adapter lenses -- are you catching some of the tube in the corners or is there just not getting enough light across the entire interior lens because the tele adapter lenses are not big enough diameter?

Thanks

John
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