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10

There is a mathematical / measurement method to calculate the effective focal length of a lens by measuring its angle of view. The formula for angle of view is given as To calculate effective focal length (f), the formula comes down to: f = d / (2 * tan(α/2)) -> Equation1 Where d represents the size of the sensor in the direction measured. d would be ...


9

How does one know if they are a 'good' singer? A 'good' guitar player? A 'good' accordion player? Okay, I admit, there's no such thing as that last one (not really - it was a joke). Like any art, part of the definition of 'good' is in the eye or ear or taste buds (think culinary arts) of the beholder. But there are also accepted norms that describe why some ...


6

Online tests? One could be simply publishing your work. Instagram? Flickr? Deviantart? 500px? Facebook? It could not be probably the best indicator (because a lot of times society simply likes dumb things) but if people like it, it is probably good. The parameter must be set: Do you like it? Do you expect your friends to like it? Do you expect your client,...


6

You can take the photography as business test: you are a player when you are paid good money for your work (any amount of actual cash is a start). Or you can take the photography as science test: you are a player when your work gets published in reputable journals (any print media to accept you for publication is a start). Or you can take the Metro Golwyn ...


5

I think any good photographer would never consider themselves as "great", "good", "amazing", "the best". There is no tool of measurement like there is in soccer. You can say "instagram views and picture purchases" is a good tool of measurement, however there are so many problems with adhering to those forms of measurements. Never consider yourself good. I ...


4

Art is inherently subjective. You can not determine if you are "good" at art until you first establish what you consider "good" to mean. "Good" could mean that the vast majority of people find your work attractive, it could mean that you enjoy your process of capturing images and find it as an effective way to express yourself, and that's just naming a few ...


3

Assuming a standard lens, standard camera, i.e. the setup can be modelled as a pin-hole camera. This doesn't work with tilt/shift, and maybe not with wide-angle lenses (if you want to know about those, we could work it out). In computer vision, often the intrinsic properties of cameras are calculated. Intrinsic because they refer to settings of the camera ...


2

You can probably calculate this by rearranging the DOF formula to solve for c, or circleOfConfusion, as @MattGrum stated. I haven't tried to rearrange a formula as complex as DOF for a while, so I hope my math is correct here: DOF = (2 Ncƒ²s²)/(ƒ⁴ – N²c²s²) The terms of that equation are as so: DOF = depth of field N = f-number ƒ = focal length ...


2

The aperture f-number describes the amount of light that passes trough the lens, for a theoretical single element lens this is also the ratio between focal length and physical size of the entrance pupil - but no camera lens sold today is a single element lens. In 1874, John Henry Dallmeyer wrote that the only way to get the "intensity ratio" (that was ...


2

I'm lazy, so for me, "best" means easiest. YMMV. :) I use Magic Lantern, with the dot_tune.mo module to perform auto dot tune. Dot tune was developed by horshak on dpreview. You don't have to take any pictures with it, it's fast, free, and uses the data of when the AF confirmation dot lights or (or doesn't), with a lens set to critical focus manually, while ...


2

Since the output from the lens toward the sensor is circular the odds are that something which is the same shape as the sensor is blocking parts of the image pathway. As lens hoods are usually circular or have petals that don't block the corners in the way you're seeing, we shouldn't be seeing this in the corners. My suspicion is that whatever it is may be ...


2

When I do such photos I alway use: a tripod to make sure the photo shows the same especially in the corners M-Mode with fix ISO-Settings to make sure exposure is same (be careful with fluctuating available light) Often but not alway I use flash and "kill" the available light to avoid light fluctuations. To analyses distortions I often use checkered paper ...


2

"Slow down, you move too fast, got to make the morning last." - Paul Simon There's only one test that matters and articulating this is the key to success on both an artistic and commercial side (and one that I don't see any other answer stating, though some came close). Does it achieve the goal you had in mind when you took the frame? That's it. That's all ...


1

You are a good photographer when people (not just family) ask you to take pictures. The next stage is when they are prepared to pay. All else is delusion.


1

There are numerous competitions, some require entrance fee, other are free (e.g. Nikon photo contest). You can easily google those, but I only participated in Nikon's, so don't know details. What you have to remember when being judged is that photography is subjective, hence one person might like your image very much, but another find it dull or plain bad. ...


1

You might sign up on sites such as 365project.org or viewbug to get your work in front of other photographers' eyes. They'll give you useful, honest (if you ask for it) feedback. Having a good eye is just the beginning. Study. Shoot. Experiment. Shoot. Fail. Shoot. As Hemingway said about writers, “We are all apprentices in a craft where no one ever becomes ...


1

What lens was it? Do you have other lenses to test? I'll start off by saying that the "good" one does look a little sharper than the "bad" one, but I'm not sure of settings or lens type. And as Matt said, there are many variables. If you have another lens, try to test it out at similar focal lengths. If not, ensure that the lens is cleaned properly. Soap ...


1

I looked at Bob Atkins' "Easy method", but it leaves you to work some astro data out. My version of his method provides all the astro how-to info and links, with step-by-step instructions, and should be significantly easier for novices to implement. http://www.pentaxforums.com/forums/pentax-lens-articles/169225-using-2-stars-determine-actual-focal-length-...


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