Focal length

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lawrenceots

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Lawrence
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I've got a Fuji Finepix S100 FS and Nikon D200.

I noticed today that even with the Fuji right up at 400mm, and the D200 at 200mm (55-200 AFS) they are about the same size.

Why is this? An error in Fuji's magnification markings!? Both were shot at the same distance, and totally uncropped/unedited.

Fuji S100 FS
5452969025_4bcf8d7540.jpg
[/url]
DSCF9539 by Lawrence Chadwick-Smith, on Flickr[/IMG]

D200 and Nikon 55-200 at 200
5453580596_f070b29b4e.jpg
[/url]
_DSC6301 by Lawrence Chadwick-Smith, on Flickr[/IMG]
 
I would imagine the Fuji's sensor is half smaller than the Nikon's, so maybe they double the focal length number to compensate and make it look better for thier marketing.

Probably in the small print is the 35mm equiv. focal length.
 
TCR4x4 said:
I would imagine the Fuji's sensor is half smaller than the Nikon's, so maybe they double the focal length number to compensate and make it look better for thier marketing.

Probably in the small print is the 35mm equiv. focal length.
Click to expand...

Spot on, I've covered this in another thread, but basically what the Fuji does to achieve an "optical zoom" is simply crop the sensor, so if it is (an already tiny) 10mp sensor the "zoom" crops and only uses say 3mp of that to give the effect of using a longer focal length.
 
no, its 400mm in the manual and on the lens, very clearly says 35mm equiv. But the wide end, 28mm, is about the same as the 28mm on the Nikon 18-55...

Its still around 100mm out...:thinking:

EDIT Sorry Graham, posted around the same time! So, you;re saying that its using digital zoom?? I've not got that turned on, and at 400mm the image is still 11 mp in size, and there is no degradation in quality/size..?
 
Last edited:
It's all doen to sensor size. Firstly, the Fuji doesn't have a 400mm lens, it has a 7.1->101.5mm lens. It gives the equivalent field of view to a 400mm lens on a 35mm (Full Frame) camera, but it is still just over 100mm at its maximum zoom.

The D200 is a 1.5x crop camera so will effectively give the same field of view as a 35mm camera with a 200mmx1.5 lens (i.e. 300mm effective).
 
Yes, I understand all the focal length increase stuff etc, but surely the 35. equiv field of view on any camera is the same? So the HS10, for example, it's 700mm lens won't look like a 700mm equivalent lens on a DSLR?
 
Let me see if I;ve got this right: You want to know why the 2 images of apparantly differin gequivalent 35mm focal length look the same?
 
lawrenceots said:
Yes, I understand all the focal length increase stuff etc, but surely the 35. equiv field of view on any camera is the same? So the HS10, for example, it's 700mm lens won't look like a 700mm equivalent lens on a DSLR?
Click to expand...
Yup.. just done the maths based on sensor size (the Fuji has a 2/3" sensor) and with the D200 at 200mm, you should have the Fuji set at 77mm... :shrug:
 
The exif files give no indication as to settings which is strange, normally such information is available with non edited photos only
 
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Yes, I want to know why the magnification is so different dispute being at the same focal length. I resized those for web use thru aperture, I'll upload high res ones shortly.

Sent from my iPhone 4 using TP Forums
 
Looks as if photos via flicker don't retain all details

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Picture 2

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ConnectionSpaceIlluminant: 0.9642 1 0.82491
DeviceAttributes: Reflective, Glossy, Positive, Color
DeviceManufacturer: IEC
DeviceMfgDesc: IEC http://www.iec.ch
DeviceModel: sRGB
DeviceModelDesc: IEC 61966-2.1 Default RGB colour space - sRGB
Directory: C:\Documents and Settings\User\My Documents\My Pictures
EncodingProcess: Baseline DCT, Huffman coding
FileModifyDate: 2011:02:17 16:33:04+00:00
FileName: pic2.jpg
FileSize: 202 kB
FileType: JPEG
GreenMatrixColumn: 0.38515 0.71687 0.09708
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ImageWidth: 1024
JFIFVersion: 1.01
Luminance: 76.03647 80 87.12462
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MeasurementFlare: 0.999%
MeasurementGeometry: Unknown (0)
MeasurementIlluminant: D65
MeasurementObserver: CIE 1931
MediaBlackPoint: 0 0 0
MediaWhitePoint: 0.95045 1 1.08905
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ProfileCopyright: Copyright (c) 1998 Hewlett-Packard Company
ProfileCreator: HP
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ProfileFileSignature: acsp
ProfileID: 0
ProfileVersion: 2.1.0
RedMatrixColumn: 0.43607 0.22249 0.01392
RenderingIntent: Unknown (16777216)
ResolutionUnit: inches
Technology: Cathode Ray Tube Display
ViewingCondDesc: Reference Viewing Condition in IEC61966-2.1
ViewingCondIlluminant: 19.6445 20.3718 16.8089
ViewingCondIlluminantType: D50
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XResolution: 72
YCbCrSubSampling: YCbCr4:4:4 (1 1)
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If originals posted via Photobucket then the exif data might be more detailed

Realspeed
 
BTW, if you measure the images, they may look the same size, but they aren't. On my monitor, in the top image, the dispenser measures 175 mm from back corner to front corner. On the lower image, the same distance is 190mm. Perhaps it is just an optical illusion and the numbers are (just about) right.
 
hmm, I'll do a proper test later on a tripod. I've never had to use the exif before, but I upload them thru Aperture flickr uploader, so somewhere along there it looses it...
 
If the Fuji is 400mm equiv field of view (on full frame) then the Nikon is 300mm.

That's not such a huge difference, and given that focal lengths are only true at infinity (and subject to 'marketing tolerance' even then) and this is not an entirely scientific comparison, it all looks pretty much as you might expect really.
 
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