Canon LTM 40 vs 40.5mm

Canon M39 M39 screw mount bodies/lenses

Dez

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Are there really two distinct filter ring standards, 40mm and 40.5?
40.5 seems to be quoted for Nikons and FSU cameras, but in references to Canons, the two sizes seem to be used interchangeably.

And if there are two distinct sizes, why???

Cheers,
Dez
 
They are different and not interchangeable for Canon lenses. The Canon wides with 40mm thread (28/2.8, later 35/2.8) need thin filters in addition.

Don't know why, always thought it was a pain.

And don't get me started on 34 and 34.5 :(
 
Can't help you, but please consider that your white text is unreadable for people who use light-coloured themes for the forum. I for one dislike reading white on black so I use a light gray background. Doubtless I'm not alone.
 
40 vs 40.5

40 vs 40.5

Oh my. 41mm for the Summarit?? I have occasionally used that lens with 40.5 filters and they seemed to fit fine. Is this precision just for the sake of precision, or non-standardization for the sake of selling stupendously overpriced accessories?

Or both?

It was specifically with a wide angle Canon where I ran afoul of this, trying to put a 40.5mm hood on a 35 f2 lens. It would go on about half a thread.

Cheers,
Dez
 
The Canon 28/2.8 works great with the 3rd party 40-xx step up rings. Not sure about other Canon 40 lens.
 
Can't help you, but please consider that your white text is unreadable for people who use light-coloured themes for the forum. I for one dislike reading white on black so I use a light gray background. Doubtless I'm not alone.

Oh. Sorry about that. I had not realized that there were different themes for the RFF screens. I have the default black background, and this computer's tired old CRT renders the grey text almost unreadable when composing.

How does the yellow work?

Cheers,
Dez
 
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this is white:
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and this is yellow:
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You can change the theme via a drop-down menu at the bottom of the page - maybe one of those could improve readability for you, too? Your browser should remember the last used setting.

I'm using the "VBP Hex Cell Xpand" option.
 
filterfind.net can usually provide a satisfactory solution for these many distinct filter sizes. If you don't see it, ask Tim. He seems to check and reply the e-mail about once a day.
 
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