[ptx] Getting EXIF data from coolpix 950 jpgs using hugin

[David Haberthür]

hey glenn,
thanks for posting this to the [ptx]-list.
as i'm rather new with hugin, and never bothered to get the correct  
crop factor (and did get rather good panoramas...) i'd like to ask if  
my calculation below is correct:

my camera has a 1/2.4" sensor (according to http://www.steves- 
digicams.com/2004_reviews/t3.html ). in metrical units this results  
in a size of 10.6 mm.
hence my crop factor would be something like 3.4, is that correct?

thanks for the help.

habi


On 02.12.2005, at 04:49, Glenn Barry wrote:

> Crop factor is the size of the CCD x A number to give 24mm x 36mm.  
> Everything is still calculated relative to 35mm camera lens focal  
> lengths in relation to 35mm film dimensions which are 24mm x 36mm.
>
> Grab the CCD sensor size from your manual, determine what it needs  
> to be multiplied by to give 24mm x 36mm and you've got your crop  
> factor. You may not need this IF the exif tags are already giving  
> effective focal length equivalents relative to 35mm film  
> dimensions. I don't know much about exif tags so this last part may  
> be totally wrong, but you should at least be able to understand the  
> principles to know if I am.
>
> Glenn
>
> Kevin Hanser wrote:
>> Quoting Pablo d'Angelo <pablo.dangelo at web.de>:
>>> Kevin Hanser schrieb:
>>>
>>>> Hello,
>>>>
>>>> I have just recently discovered and started using the following  
>>>> tools to create
>>>> panoramas:  autopano-sift, hugin, panotools (PTStitcher), and  
>>>> enblend.
>>>>
>>>> I have an old Nikon Coolpix 950 camera, and I have been unable  
>>>> to automagically
>>>> read the lens settings using the "load EXIF" feature of hugin.   
>>>> When I click on
>>>> an image in hugin and pick "load EXIF", it then brings up a box  
>>>> asking me for
>>>> the focal length.  I've been putting this in manually for now  
>>>> and it works
>>>> good, but I'm curious as to why it isn't able to get the info  
>>>> from the EXIF
>>>> info in the jpgs?
>>>
>>>
>>> Hugin also needs information about the pixel size, because  
>>> without it,
>>> the focal length is meaningless.
>>>
>>> Some camera do not save both in the EXIF data. Can you email me a
>>> example image privately?
>>>
>>> ciao
>>>  Pablo
>>>
>> I think what I actually meant was the "crop factor".  I'm not  
>> entirely sure how
>> to determine this... I've been basing it on the F-stop and that  
>> seems to work
>> ok, but I'm not sure if that's correct or not.  I will send you an  
>> image
>> shortly...
>> thx!
>