CCD crop factor


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Illidan

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Nov 15, 2004
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#1
hi guys. i don realli understand what u guys mean by 1.5 crop factor on a ccd chip. can explain in detail? if its a 1.5 crop factor + a 95% croping on d viewfinder, would d pic be enlarge alot more once its print out than looking through d LCD? thanks alot
 

ortega

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Nov 2, 2004
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#2
if you are looking at the LCD it is 100% (I think)
The view finder is not 100% (%tage depends on camera)
Crop factor has reference to lenses and their field of view.

If you are compairing with the image on the LCD then there should not be a difference.
 

snowspeeder

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#3
Crop factor means if your lens zoom is 20 mm, taking into consideration of 1.5x crop factor comes to 35 mm.
 

Witness

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Mar 18, 2004
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#4
this is because the ccd sensor is smaller than a film plane...

so ya field of view gets multiplied by 1.5x....

everything else...properties of the lens...distortion level etc stay constant...

cheers..
 

user111

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Jul 27, 2004
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#5
95% viewfinder just means u see only a bit less ( of the original surrounding edges) of the 1.5x cropped image

if u want to print out 4R, 6R, 8R, or whatever print-out size, etc, simply resize (in terms of how many pixels x how many pixels) the image file accordingly to the ratio for the particular print-out size
 

majere2sg

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#6
Illidan said:
hi guys. i don realli understand what u guys mean by 1.5 crop factor on a ccd chip. can explain in detail? if its a 1.5 crop factor + a 95% croping on d viewfinder, would d pic be enlarge alot more once its print out than looking through d LCD? thanks alot
In case you doesn't know.. u can't preview thru the LCD for a DSLR.. The LCD should show u exactly how the picture look like after u took the picture and review it.
 

espn

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#7
Digital's sensor is based on film's size of 36mm x 24mm, this is the 135 Format or 35mm format.

Sensor being expensive to manufacture, they decided to make the size smaller, ie: 1.5x smaller -> (eg) 24 x 16.

The sensor is now half the film size, thus of course, captures less details since the top/bottom/sides are cropped out.

All glasses used on bodies with 1.5x crop/FLM, the view is also cropped, therefore we say 70-200mm is having a view of 105-300mm on the DSLR. The focal length is still 70-200, but the image's center is cropped out as if the glass zoomed 1.5x more.

Hope it helps...
 

cuxiaowang

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Feb 1, 2005
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#8
Witness said:
this is because the ccd sensor is smaller than a film plane...

so ya field of view gets multiplied by 1.5x....

everything else...properties of the lens...distortion level etc stay constant...

cheers..

this gets interesting....now does the handhold threshold remains the SAME?...aka say 18mm wide, does it mean least 1/20 to retain sharpness pics?..or should it be 1/30 (crop factoring comes in, 18 x 1.5 = 27) just to play safe.

hmm.. :think:
 

Witness

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#9
to be i believe it should be the same as the focal lenght used...... its juz a croppin of a larger size anyway....

anyway 1/focal lenght is a guideline....no more....hehe.....

cheerss...
 

cuxiaowang

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Feb 1, 2005
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#11
pls pardon, maybe i overlook, but somehow i didnt catch any clear cut point on the handhold 1/focal length part. any old bird like to intrude..
 

Jun 27, 2002
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#12
cuxiaowang said:
pls pardon, maybe i overlook, but somehow i didnt catch any clear cut point on the handhold 1/focal length part. any old bird like to intrude..

(DISCLAIMER)* i am not a bird.....

The handhold 1/focal length is just a GENERAL rule, use whatever shutter speeds you are comfortable within your intented focal length.
 

user111

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Jul 27, 2004
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#13
Belle&Sebastain said:
(DISCLAIMER)* i am not a bird.....

The handhold 1/focal length is just a GENERAL rule, use whatever shutter speeds you are comfortable within your intented focal length.
yup..own level of confidnce is the most impt factor
 

AReality

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Jun 9, 2003
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#14
it's 1/30s, as in your example in post #8.

Assume you're printing on 4R, you'll have to magnify more for a cropped sensor, than a full frame, to 6 inch by 4 inch. So, any handshakes are magnified also.

To give u a better example, let's look as P&S digicam lenses. They have focal length like... 7mm... But their field-of-view(FOV) is similar to 28 or 35mm, depending on other factors. So should I hand hold at 1/7s? do u think 1/7s is enough for a FOV of 28 or 35mm(full frame equivalent).

What if when the sensors become smaller, with a crop factor of 35x?
U'll need a 1mm lens to replicate a view of 35mm on full frame.
So should I hand hold at 1sec now? or still 1/35s?

regards,
AReality.
 

Jun 27, 2002
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#15
cuxiaowang said:
the most interesting thing is, my repeated question remains unanswered...hmm, do i smell more philosophical air than substance?...birds or otherwise. pardon the pun ok!

now seriously think about its, guys...did ANYONE ever did answer my question upfront...when you handhold a 18mm for a less than full frame DSLR, is it technically (not theoretically) superior to work out at 1/actual focal length or just simply 1/cropped factor length would do. if yes, why? if no, why?

at this point, believe anyone uninformed, or even as put, "generally" informed (thats including me course) would just play safe to hold at the larger value (FL). but this is still a geniune query nonetheless..not to dent any egos, is this too much to ask for here or is just a tat tuff to say "I dont know." :eek: ....cos i admit i dont ;)
photography is more science to you than arts to me, the shutter speed i determine purely depends on the situation. Generally i dun know if you want to hear that you MUST use this or that, it puts me off BIG TIME.

i lay my own rules to my game, and as the handholding shutter speed as a reference not CORRECT answer. If you choose to think this way your pictures can only be sharp to your content whereas i still want to capture my thoughts and i will convery though my photographic eye, be it my pictures turn out less than a mess of fury blurness.

if you feel so much need of a absoulte answer i can safely say in photography there is none.
 

snowspeeder

Senior Member
Feb 16, 2004
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#16
The technical/scientific aspects of photography can only serve as a guide.
True substance in photography is measured by the individual's ability to produce great images expressed passionately from one's imagination. Understanding photography through math, is in essence, failure to comprehend the greatness of this art itself.
 

cuxiaowang

New Member
Feb 1, 2005
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#17
per se, i am not asking for maths or physics for the matter. just a technical opinion, philosophy quite apart.

neither am i insinuating anyone and definitely not out wanting to put off anybody, big time small time. lets not digress and get temperate, i am just asking a technical question. usefulness or absoluteness or personal rules aside. where i sound numbish, kind treat as hysteria, ok fair brothers?!

that said, my sincere appreciations to witness and areality for the kind patience. whats cropped then whats magnified. would have been my best bet too.

to whom i owed an apology, i have retracted my earlier statements in goodwill. thats what this community is all about isnt it. yeo cheers!
 

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