File :-(, x, )
Anonymous
I keep hearing that one of the lenses you should always have is a 50mm f/1.7. Why is this? Aside from the obviously larger aperture wouldn't a general zoom lens (like 18-70 f/2.8) suffice?
>> Anonymous
Because PRime lenses (ones that have a fixed single focal length) Are generally better quality than their Zoom counterparts, Distortion is low, Contrast and color rendition are usually good, And their sharpness often surpasses zooms by immense amounts at wide open aperture's.

Also the 50mm f1.8's are dirt cheap, So theres pretty much no reason to have one, They also rock in low light!
>> Anonymous
They rock in low light? Is that just because they have a larger maximum aperture?
>> Anonymous
>>53420
In a word, yes.
>> Anonymous
I was told the 50mm lense is exactly what the hman eye sees.. is this true?
>> Anonymous
>>53434

I wouldn't say "exactly", but close to it.
>> Anonymous
>>53420
bingo
>> Anonymous
>>53434
On 35mm film camera.
>> Anonymous
Actually, it's hard to compare human eye to a photographic lens. The eye has a very wide field of view, but most of it is low-resolution peripheral vision; the area of sharp vision is only a small spot in the center. A camera, on the other hand, has narrower FOV (unless you use a fisheye lens), but the whole image is nearly equally sharp.

Generally, the field-of-view of a 50mm lens on a 35mm camera is regarded as most natural-looking for the human eye. However, most point-and-shoot cameras use 35mm equivalent focal length (which corresponds to about 90 degrees FOV) as "normal".
>> Anonymous
>>53410
>Also the 50mm f1.8's are dirt cheap, So theres pretty much no reason to have one, They also rock in low light!

Not for all cameras. Olympus fails @ cheap primes (their primes are either narrow aperture macro or OVER 9000$ high-end telephoto), and Sigma lenses for 4/3 bayonet are hard to findand far from cheap either.
>> Anonymous
i've always been interested in this lens/human eye comparision - so, is there any lens that resembles the human eye (as far as this is even possible) or would i have to use ugly postprocessing hacks?
>> ac !!VPzQAxYPAMA
>>53494
Actually, a Holga or a Diana would probably be a valid comparison. Or an SLR with a Lensbaby, to a lesser extent. Sharp in the middle, kinda blurry and peripheral everywhere else.
>> Anonymous
>>53494
A lens/sensor system that resembles human eye in terms of FOV and resolution (dynamic range and color reproduction are harder) is definitely possible, but no one really needs it in photography. We move our eyes when we look at a photograph, so constant sharpness from edge to edge is preferred to sharp center and blurry everything else.
>> elf_man
I've noticed that 55mm (about 85 equivalent on my d40, I think) fits what I see, neither closer nor farther away.
>> Anonymous
I have read that 50mm was just chosen because it's reasonably close to "normal," but that longer lenses were easier to produce in the early 35mm days, so they just stretched it out from the "true normal" of 42mm.
>> Anonymous
>>53471

Ah, I see. It would be pretty much the best damn thing ever if they could make a lense that operates JUST LIKE the human eye.. Photography would gain a whole new level of awesomeness.
>> Anonymous
>>53552
A camera that takes images just like the human eye would require you to use a special device to view them that gives you a wide FOV and fixes your eyeball at the same time. I doubt that it's a good idea - inability to move or refocus your eye would be extremely unpleasant.

IIRC there were similar experiments with stereoscopic photography that required special goggles for viewing the photos, and they all failed because it was too inconvenient.
>> ac !!VPzQAxYPAMA
>>53561
Also, the goggles, they did nothing.
>> Anonymous
>>53561

Well, I don't mean operates, I mean.. A lense that see exactly what human eye sees... There has been a few times I wish I could take pix with my eyes.... because of some of the stuff i've seen
>> ??????? !KEBab7wem6
>>53717

The "ideal eye-like lens" would be probably be closer to a 50mm with a 160-degree FOV or so, mainly because the photosensory area of the eye is curved. While this probably wouldn't be a problem, I think the main problem in creating a camera that acts like the human eye is the current limitations to the dynamic range of cameras and screens. I don't remember any exact values, but the human eye has a dynamic range that pretty much leaves any other manmade sensor or screen in the dust.
>> Anonymous
     File :-(, x)
>>53719
To add a picture to your explanation, the D-shaped graph here is a representation of the colors that the eye can see, while the triangle inside of it represents the colors contained in the RGB color space.
>> Anonymous
     File :-(, x)
>>53746
He wasn't talking about color at all, dynamic range is just about brightness. Not that having sensors with incredible HDR capabilities would matter that much, you can do the same with multiple exposures now, but good luck representing those fifteen stops of dynamic range with ink on paper...

Also, the triangle in your image is sRGB, an important distinction to make (image related).

Camera-Specific Properties:Camera SoftwareAdobe Photoshop CS2 MacintoshImage-Specific Properties:Image OrientationTop, Left-HandHorizontal Resolution72 dpiVertical Resolution72 dpiImage Created2005:05:14 10:20:39Color Space InformationUncalibratedImage Width310Image Height316
>> Anonymous
>>53746
>>53752

Multiple exposures aren't always possible, or even usually possible. Wind blowing trees, stuff moving, etc.

Even with an auto-bracketing camera, there's a little bit of a lag that can ruin an HDR shot.

I've taken shots I would've liked to have bracketed and put into HDR, but it was impossible by their nature.

And also, I don't think the result of an HDR image would be exactly the same as a sensor with more dynamic range. HDR images look edited, look computer-generated.

On another note, what is ProPhoto RGB? I might have to start using that if I ever start making actual, physical prints. I'm sure there's some paper that has better dynamic range than the one shown in the chart.

What does everyone here use? I use sRGB, because it works for everyone and at the moment, I only make digital "prints" to post to /p/ or show to people I know. Also, I'm too lazy to go through the trouble of calibrating everything to Adobe RGB.
>> Anonymous
>>53754
The edited look of hdr images has nothing to do with multiple exposures, it's the result of displaying an image that has a lot of dynamic range on a medium (monitor/paper) that doesn't. A hdr image will look perfectly natural if you look at a part of the dynamic range within your mediums capabilities instead of compressing it.

Sure, some papers/inks have more possible dynamic range than others (this has nothing to do with the above chart btw, which is still about colour, not dynamic range) but you'll never be able to accurately represent the difference in brightness between a face in the shade and one in bright sunlight on a piece of paper lit by a desk lamp.
>> Anonymous
>>53758
>difference in brightness between a face in the shade and one in bright sunlight on a piece of paper lit by a desk lamp.

What can do this? Projections? Some monitors?

>mediums capabilities instead of compressing it.

Same here. What mediums?
>> Anonymous
>>53765
A specially-designed CRT (with high peak brightness + fine control of intensity) in a dark room can probably provide enough dynamic range.