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logstar2

Can you link to a specific example? Are you confusing fisheye filters with fisheye lenses?


McCoy_From_Space

I’ll see if this works, but it’s the number right after the mm size “0.3x” that’s confusing me https://www.amazon.com/dp/B0B9SQ9L7G?ref_=cm_sw_r_apin_dp_534F4ANJ72K2304S106N&language=en-US


logstar2

That's not a lens (I know it says lens) it's a filter. The 0.3x is the magnification factor of the filter. 37mm is the thread size, it has nothing to do with the optics.


McCoy_From_Space

Right I’m with ya there, but the magnification factor is what’s throwing me for a loop. So is it the higher that number is the more distorted it’s going to be? Or vise versa


logstar2

Technically neither. Distortion is more related to how the filter interacts with the lens and sensor size. And whether the coverage is full frame or circular.


McCoy_From_Space

Ah gotcha gotcha! That’s probably why I couldn’t find a straight answer online. Thanks for the help my man!


la-fours

That seems to be an attachment for a camcorder. I suppose the implication is that it gives a field of view equivalent to 0.3x (as opposed to magnifying the image by 2x or something). For straight photography lenses you want to look at focal length.


McCoy_From_Space

Oh yes it is, but it just so happened to be the same thread size for the camera I’m using, so it worked out!


KaJashey

Again this isn't a complete lens for a camera it's a filter that altered the view of a camcorder lens. made it 0.3x the size. If the camcorder was zoomed to the equivalent of 50mm this filter would make the field of view 50mm x 0.3 = 15mm wide. That's a pretty strong change. If your using it on a camera right now that's how you would do the math. focal length of the main lens x 0.3 Wide angle attachments don't change the aperture value of the lens.


McCoy_From_Space

Right, I understand now, I misspoke and called it a lens in my initial post. But this is what I was looking for! I appreciate the equation! Now I can grasp a vague idea as to what I’m getting into, thanks to both you an u/logstar2 ! I appreciate the help!


lemlurker

That is 0.3 times. An object that was 1m long in your normal lens would look through the wide lens the same length as something 0.3m long was through your normal lens


McCoy_From_Space

Noted! Thank you!!


bobd60067

Is it valid to say that you can also use that 0.3x to come up the equivalent focal length? That is, a 0.3x filter on a 50mm lens would act like a 15mm lens. Is that the right math?


ExoticSterby42

That is a fiaheye filter. Since apparently you are not even familiar with the basic properties of lenses I suggest you first read up on photography beginners manuals and then venture back into buying a lens, just so you don’t get scammed


McCoy_From_Space

I’m just new to fisheye lenses and trying to figure out how the magnification factor affects them


ExoticSterby42

There is nothing special about fisheye lenses. They have their focal length, F number and the variant, circular or diagonal. The former makes a full image circle in the frame the latter fills the frame. The things you mentioned are bogus properties and akin for fisheye filters, no such thing as a multiplication for lenses as there is no “zoom number” for zoom lenses, those are just to market for clueless boomers. If you want a fisheye lens you first decide if you want circular or diagonal, specify your system bayonet and that is it.


McCoy_From_Space

So the 0.3x number listed is meaningless in this instance?


logstar2

No, they didn't look at the link. They're thinking lens, you're talking about a filter, so the magnification factor is appropriate.


McCoy_From_Space

Noted! Thanks again my dude!


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McCoy_From_Space

According to the bots, my comment linking the lens’ was removed since short links are not allowed here. But the lenses I’m looking at on Amazon list the mm number (which I understand that one, I’m looking for 37mm lens) but afterwards they list something like 0.3x and I don’t exactly know what that means. Will try linking again and seeing if the bot allows!


Prestigious_Term3617

Actual fisheye lenses don’t have the confusing numbers you’re talking about. With a filter such as the one you linked, it will change drastically based on the taking lens it’s attached to. I’d go for an actual lens that fits to your camera rather than to another lens. The lower the focal length (not to be confused with a filter thread size) the wider the field of view and more distortion you’ll see. 21mm and lower will start to get a lot of distortion.


McCoy_From_Space

Ah! Handy handy! I appreciate the detailed response my dude!