Hi Sneha,

Glad that worked for you.  I'll include it in the package on my website for 
future downloaders.

The -s factor doesn't have to be exact.  It just has to have the correct 
relative relation between captures.  If you capture your images in the usual 
1-EV separation, you might use for example:

img1.jpg                1/60th second
img2.jpg                1/125th second
img3.jpg                1/250th second

hdrgen -s 1 img1.jpg -s 2.0 img2.jpg -s 4.0 img3.jpg

In other words, you want the pixels times the multipliers to roughly equal each 
other (within the limits of exposure range).  If you happen to know what the 
absolute level of some image is, you can use that.  Here is an approximate 
formula for the -s factor based on ISO, f-stop, and exposure time:

        s2nits = 87*f_stop^2/(exp_time*ISO)

Cheers,
-Greg

> From: Sneha Jain <[email protected]>
> Date: July 13, 2017 5:36:55 AM PDT
> 
> Hi Greg,
> 
> Thank you so much for providing this version. I am glad to inform you that 
> this version is working with Linux 64-bit. Though I am struggling to 
> understand the -s stonits  factor for each LDR image that I need to specify 
> for getting an HDR image. I am connected to a fish-eye lens all-sky camera 
> and unable to get this factor automatically. If you could suggest me on how 
> to get this; it would be really great. 
> 
> Thank you.
> 
> Regards, 
> 
> Sneha Jain
> On Wed, Jul 12, 2017 at 7:40 PM, Gregory J. Ward <[email protected]> 
> wrote:
> Hi Sneha,
> 
> Try this version and tell me if it's any better.  Building under Linux is 
> painful because of the required libraries (OpenEXR in particular).
> 
> Cheers,
> -Greg
> 
> P.S.  I "cleared" your post to the HDRI mailing list, but you need to 
> subscribe to the list using the address you post with in order for this to be 
> unnecessary.
> 
> 
> 
>> From: Sneha Jain <[email protected]>
>> Subject: Request for hdrgen's updated version for Linux 64-bit system
>> Date: July 12, 2017 3:34:08 AM PDT
>> To: [email protected]
>> 
>> Dear Mr. Gregory Ward,
>> 
>> I am Sneha Jain pursuing MS in Building Science from International Institute 
>> of Information Technology Hyderabad, India. I have gone through this 
>> previous Radiance thread about running hdrgen on Linux. I have tried using 
>> hdrgen from anyhere.com but then I came to know that it only works on 32-bit 
>> system. Please let me know if there is any latest version of hdrgen 
>> available for 64-bit Ubuntu and if you can send me the same.
>> 
>> ​Thank you.
>> ​
>> Regards, 
>> 
>> Sneha Jain
> 
> 
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