At what point does longer focal length no longer matter? I want to take photos of things far away, like across the street.
I would do a camera test if I still owned my 70-300 Canon kit lens but I don’t. Right now the longest focal length I own is a 24-70 for my Sony.
I remember about that lens, once I got out past 150-175m, it seemed like the FOV was just cropping in more rather than actually feeling closer to the subject. But that was a cheapo kit lens that had a terrible reputation. Does that just apply to cheap lenses or do more expensive lenses have more magnification?
Is there really a significant difference between 300, 400 and 600m lenses? Of course I have no physical access to any such lenses at the moment.
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Well clearly you’ve never shot birds, without long focal lengths most wild birds will be tiny in your frame.
“Is there really a significant difference between 300, 400 and 600m lenses? Of course I have no physical access to any such lenses at the moment.”
yes
https://www.flickr.com/photos/186162491@N07/albums/72177720312764722/with/53080603595/
the shot of jupiter was only possible with a supertelephoto and a 1.4x extender.
Subject compression is noticeable all the way past 600mm, just look at landscapes shot at that focal length and see how close everything gets together.
It’s harder to tell with portraits because someone’s nose to eye distance isn’t that much to begin with. I love long telephoto portraits though, thinking about buying a 300/2.8 just for that reason…
I’d say the real answer depends on what conditions you’re shooting in. If you have a 400 or 600 2.8 they make a gigantic difference over a 200mm lens both in real reach, sharpness and importantly bokah. But if you’re shooting on a hot football field for instance you’re going to run into distortion from the atmosphere.
Honestly there is just very little comparison between a 200 and 400, let alone a normal focal length lens.
it seemed like the FOV was just cropping in more rather than actually feeling closer to the subject.
Yes that’s what changing the focal length of any lens does. It enlarges the image so that a smaller portion the image fills the sensor (the rest is effectively cropped out). The only difference is if you were to take a photo with a 300mm lens and then took one with a 150mm lens and cropped it to match the 300mm, and then took one with a 75mm and took that and cropped it, you’d still have the full resolution on your 300mm shot, your 150mm shot would be much smaller, and your 70mm shot would be tiny with very little detail.
You should see the same effect if you shoot something with your 24-70mm at 24mm vs 70mm.
More expensive lenses will be sharper. I’m certain if you compared your canon 70-300mm at 70mm vs your Sony 24-70 at 70mm, the Sony would probably be noticeably sharper, and I think that canon got worse at longer lengths.
And also you can hit diffraction, if you shoot at f/11 or smaller (f/16, f/22) that diffraction will further soften the lens. So shooting at f/5.6 to f/8 will be better, but if the lens is crap and soft at f/5.6, that doesn’t help you as much.
Finally, there is atmospheric haze. If something is very far away, there is just a softness in the atmosphere from different factors from smog to mirage heat that can further soften your image.
There is a flattening effect of focal length, but it comes from changing your preferred working distance rather than an optical effect. If you take a picture of someone at 10 feet with a 20mm and an 85mm then crop in the 20mm picture it will look the same. However, if you fill the frame with a persons face with a 20mm and then with an 85mm by foot zoom you’ll get different pictures due to the change in the ratio of distance to the lens.
If you have something 1 Unit wide and it’s 1 Unit away from you, then you move it so it’s 2 units away from you then it goes from taking up 60 degrees of your field for view to 28.96 degrees. However, if it starts at 10 units away then moving it one more unit goes from 5.7 degrees to 5.2 degrees. So yes, it is just cropping, and not distortion but it still changes the look of the photo by changing the effect of distance on relitive size in the final image in a lot of typical uses.
You can see the same thing in huge murals of people: from a distance they look like normal propotions, but when you get close and at an angle they start to look really weird because the relative distance between parts of the painting is different than how we’re used to seeing people.
If you set up your tripod and took a photo of a subject with a 600, 300, 150 and 75mm lens all from the same place, then cropped the 300, 150 and 75mm images to the same as the 600 then the main difference would be the resolution, as you have to crop away more and more of the image.
If, however, at each step you moved the tripod forward half the distance then the subject would stay the same size but because the camera is getting closer each time the perspective to the background would be changing and the FOV would appear totally different because of that.
The longer focal length means that you can fill the frame with the subject from further away without having to crop into it as much.
You’ll hit a point where you sill start getting worse results - not necessarily because of the lens but because of the atmospheric conditions. Heat haze caused by he sun heating up the ground will give a mirage like image and start to blur objects further away - tyhis all depends on location and conditions.
Focal length always matters, depending on the job at hand
Absolutely, they let you fill the subject in your frame.
Cropping images equals resolution loss and noise. You want to avoid that if you can.