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Equivalence - very good article - Printable Version

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Equivalence - very good article - dave9t5 - 03-04-2015

Very clear article on lens equivalence at the mysterious background blur blog with very nice examples:

 

http://www.backgroundblur.com/#!/articles/54e859c2a0849cd703c06c8b

 

Definitely one I will be bookmarking this for my own reference and also for every time it has to be argued about explained to those who are still ignorant learning about the concept!  

 

 




Equivalence - very good article - Scythels - 03-04-2015

Bad article.  "Myth #2" is a truth and "myth #3" is for all intents and purposes true. 

 

Klaus, maybe an article on this is necessary...  Could be a good one to insert before the series.




Equivalence - very good article - Brightcolours - 03-04-2015

Nice to see that you now get that 90mm f3.6 on FF is equivalent to 45mm f1.8 on four thirds.

 

There are some errors in above article, even in the examples.




Equivalence - very good article - JJ_SO - 03-04-2015

in my eyes, this equivalence debate is rather bullshit. Like comparing a remote toy plane to a delta-glider to a airplane - all of them can do things the others can't and only complete idiots would say the toy plane flying at 80 km/h is equivalent fast or loud to the 10 times bigger jet flying at 800 km/h.

 

Forcing scales go be equal is pointless and not helpful at all, especially if the consumers buying smaller cameras do it with the reason to have a smaller camera. What good for is it to tlell people who never used a camera what equivalence the FL is? I never looked to a 2000 mm lens and onyl once through a 1000 mm pointing at the other side of the street. How this lens behave in the wild - how could I know? And regarding the article: I just browsed over it, but if he wants to equivalence, he really should be able to bring the subjects to the same size, otherwise it's comparing apples with bananas.




Equivalence - very good article - felix - 03-04-2015

The article itself is not very good - some statements are wrong and most of the image samples are just plain bad... However, I think the conclusion sums up the issue quite nicely  Wink



Equivalence - very good article - Brightcolours - 03-04-2015

Quote:in my eyes, this equivalence debate is rather bullshit. Like comparing a remote toy plane to a delta-glider to a airplane - all of them can do things the others can't and only complete idiots would say the toy plane flying at 80km/h is equivalent fast or loud to the 10 times bigger jet flying at 800km/h.

 

Forcing scales go be equal is pointless and not helpful at all, especially if the consumers buying smaller cameras do it with the reason to have a smaller camera. What good for is it to tlell people who never used a camera what equivalence the FL is? I never looked to a 2000 mm lens and onyl once through a 1000 mm pointing at the other side of the street. How this lens behave in the wild - how could I know? And regarding the article: I just browsed over it, but if he wants to equivalence, he really should be able to bring the subjects to the same size, otherwise it's comparing apples with bananas.
We know you think it is bullshit, but you always come up with bullshit comparisons like that plane stuff above.  It makes no sense what so ever.

Equivalent lenses just is about understanding how to get a same certain FOV and/or certain DOF with different formats. Something real photographers have done through the decades.

 

And the planes thing above? They obviously have nothing the same. Indeed one needs to be a complete idiot to say above stuff about the planes, and it has no equivalence to the lens equivalence subject. You refuse to get lens equivalence, which is fine. But then refrain from posting about it in this manner?



Equivalence - very good article - Brightcolours - 03-04-2015

Quote:The article itself is not very good - some statements are wrong and most of the image samples are just plain bad... However, I think the conclusion sums up the issue quite nicely  Wink
Yes, I agree. The "conclusion" is pretty good, while in the text and samples are errors.



Equivalence - very good article - davidmanze - 03-04-2015

 These articles and forum threads seem to be one of the most argued about topics of the pros and cons of available formats and their characteristics, creating endless discussions about "understanding" field of view and "coming to terms with" focal length vs depth of field vs equivalence etc

.

    No-one is "ever" agreed!   Throw  T stops and F stops into the equation and you can talk forever.

 

   Add to the fact that it has now become "fashionable" to state we are becoming subject to a "DOF aperture scam" by camera manufacturers, use the words "conspiracy" and "hoodwinked" and "sold down the river" and you have a recipe for a veritable riot! 

 

 All this is accompanied by two explanatory example images, the first from an "Iphone" showing a fly's eye millimeters away from the lens with a backdrop of a distant mountain range all absolutely "tack sharp",  the second is a  portrait shot  taken from a 10X8" plate camera at F0.5 with the focus point on the eye, the eyelashes of course are completely OOF and the subject is impossible to recognize from Adam.                                                                                                                                                             

 

 I rarely read those threads just like I didn't really read this one! Rolleyes




Equivalence - very good article - popo - 03-04-2015

Sounds like it isn't worth clicking that link then? It isn't a hard concept to understand, only that some people choose to misrepresent it e.g. "I don't care about one part so I'll ignore it and only do the other bit to make things sound better than they are". That is usually when most of these pointless arguments start.


Equivalence - very good article - Guest - 03-04-2015

Quote:in my eyes, this equivalence debate is rather bullshit. Like comparing a remote toy plane to a delta-glider to a airplane - all of them can do things the others can't and only complete idiots would say the toy plane flying at 80 km/h is equivalent fast or loud to the 10 times bigger jet flying at 800 km/h.

 

Forcing scales go be equal is pointless and not helpful at all, especially if the consumers buying smaller cameras do it with the reason to have a smaller camera. What good for is it to tlell people who never used a camera what equivalence the FL is? I never looked to a 2000 mm lens and onyl once through a 1000 mm pointing at the other side of the street. How this lens behave in the wild - how could I know? And regarding the article: I just browsed over it, but if he wants to equivalence, he really should be able to bring the subjects to the same size, otherwise it's comparing apples with bananas.
 

I'm pretty sure there isn't a debate, because it *is*. It would be like debating gravity.

 

Which is actually a pretty good analogy - the gravity on Jupiter is different from on Earth. Yet we can compare Jupiter to Earth, even though the result is somewhat meaningless since a human couldn't exist on Jupiter.

 

So what that the 45mm f/1.8 shot is only exactly identical to the 90mm f/3.6 in a completely hypothetical/perfect/impossible world. It gives a benchmark. And 135 film is better than any other metric to compare.