Aperture, FNumber, and Lightsource EXIF data

karlyh

New member
I'm in need of a little advice and I didn't know where else to ask it as I couldn't find a 'site questions' thread anywhere. Excuse my tech ignorance but can someone tell me in my camera info section of any particular photo what these few terms mean exactly..... I don't recognize the number value. Thanks in advance for your help and for all the kind and encouraging words here!
  • MaxApertureValue:4
  • FNumber:11
  • LightSource:9
 
Re: Hello!

Excuse my tech ignorance but can someone tell me in my camera info section of any particular photo what these few terms mean exactly..... I don't recognize the number value. Thanks in advance for your help and for all the kind and encouraging words here!

  • MaxApertureValue:4
  • FNumber:11
  • LightSource:9

Max Aperture Value is referring to the largest f/stop (opening) that the particular lens has.

For instance:

18-70mm f/3.5-4.5G ED IF AF-S DX Nikkor Zoom Lens

18-70mm is the designation for the focal length (wide angle is 18, narrows down to 70mm).
f/3.5-4.5 is the aperture, f/3.5 being the larger opening, found on the "wide end" of the lens, compresses as the focal length increases. What makes the expensive, professional lenses as expensive as they are is that as the focal length increases, the aperture opening remains constant. It requires a lot more precision glass, a lot more engineering, and therefore they charge a LOT more for that glass.
The ED stands for Extra-Low Dispersion, the IF is Internal Focus (lens doesn't "grow" as you zoom in), the AF-S is "Auto-Focus Silentwave" which means the focusing motor is in the lens instead of relying on a body-mount focusing motor, and finally the DX stands for the size of the sensor that the lens was designed to use. FX is a full-frame (35mm) sensor, while the DX is an APS-C size sensor.

Back to the f/number - this relates to what the aperture opening was when the image was captured. In the instance you provide, someone wanted some extra depth of field, color absorption, or was dealing with too much light for the shutter speed or ISO, so they chose to "stop down" the lens to provide less light opening.

I learned that image capture can be adjusted like a triangle.

The three sides are:

ISO - how sensitive the "film" (or sensor) is to light
Aperture - how MUCH light the lens lets the "film" (or sensor) see.
Shutter speed - how LONG the "film" (or sensor) gets to "see" the light.

GG1.jpg


Here's the EXIF data:

Camera Make: Nikon Corporation
Camera Model: Nikon D300
Pixel Size: 4304 x 2852 (12.3MP)
Aperture: f/5.3
Shutter Speed: 8.0s (long-exposure for the colors and the light coming from the lower right corner of the image, which was the full moon over the city)
Exposure Bias: 0ev
Focal Length (35mm): 142.0mm (my camera is a DX, which has a smaller sensor than a 35mm or full-frame camera, therefore this is the comparable focal length)
Focal Length: 95mm (the actual focal length reading on the lens on the body of my camera)
ISO: ISO 200 (if I did this shot again, I'd shoot ISO 100, to make the exposure even longer, since the lower ISO is less sensitive to light)
Aspect Ratio: 3:2 (standard ratio on APS-C sensor cameras from Nikon)
Lens Minimum (mm): 18.0mm
Max. Lens Aperture: 4.8 (at the 95mm focal length, this is the maximum aperture <opening> that this lens will provide)
Lens Maximum (mm): 200mm
Lens: AF-S DX VR Zoom-Nikkor 18-200mm f/3.5-5.6G IF-ED
Color Model: RGB
Profile Name: Adobe RGB (1998)
 
Last edited:

karlyh

New member
Re: Hello!

This is better than a manual could ever provide and wow! Thank you for the time you have spent here... It will take me some time to allow these things to unfold, so to speak. But I'm saving this page and keeping it as a guide.
I'm learning so much here and validating other things I've either tried and/or been successful with or sometimes not. What I'm trying to say is.... I've just been 'doing it'.. Taking the photos, relying on instinct for what it is I 'see'.... and relying on luck as to how I capture it. Learning the ratio's seems daunting unless it can be broken down into parts as you have done for me here. I don't rely on preset buttons, never have but at the same time I pay little attention to the numbers/settings that I'm using. I could probably always get away with that..... but I'd really like to learn the why's and why for's instead of always just guessing. I've walked away from some pretty exciting 'would have been' shots after shrugging my shoulders as to what exactly I needed to do to get the shot. ESPECIALLY night shots.
Your photo of the city is awesome by the way... Just stunning!

Thanks again!!
 
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