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UltravioletPhotography

Solar spectrum lens test - Olympus M.Zuiko Digital 17mm f/1.8


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LENS: Olympus M. Zuiko Digital 17mm f/1.8

Camera: Olympus E-PM1 full spectrum

 

 

I have some trouble processing images. They are little blurry if processed from JPG or little overexposed if processed from RAW without corrections. Need advise which to post or how to process properly. RAW is good for examining Fraunhofer lines and guessing wavelengths.

 

Lens in manual focusing mode. Note - it does have UV focus shift:

post-192-0-84939900-1526508836.jpg

 

ZWB3 (2mm) from JPG

post-192-0-86047000-1526507807.jpg

 

ZWB3 (2mm) from RAW

post-192-0-73234100-1526507861.jpg

 

 

Just in case, full photo how it looks with huge IR leaks and reflections inside spectroscope, resize only:

post-192-0-93909800-1526508931.jpg

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Andy Perrin
Yeah, the RAW negates my earlier comment - I think we can see the shorter wavelengths there. What a difference! It seems like you should work from the RAW always? That is what I do.
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Andy, they are not aligned.

 

They are aligned only in pairs JPG vs JPG, RAW vs RAW

 

How to not display attachments in this post? I moved them to 1st.

post-192-0-19904500-1526509424.jpg

post-192-0-16018800-1526509449.jpg

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Andy Perrin

I was not going by location but by whether one can see the false yellow colors that correspond to the shorter wavelengths. Obviously the exposure difference matters there too. But the blurring effect of the JPG makes everything uncertain.

 

Edit: I forgot to ask how you white balanced. One would not see the false yellows anyhow without a UV white balance.

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Well, JPGs are just auto, and RAWs are dumb processed without any corrections using XnView. Any other processing I tried just killing details.

White balance can't shift Fraunhofer lines. Goal is to check lens transparency and focus shift.

 

I may test different white balances in other thread, not going to mix everything in single thread.

 

Seems I need to make separate thread for each lens, original idea was to have one thread for native lens and other for adapted manual lenses.

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I have no idea about minimum wavelength. There is not much glass or coating inside. I have photo with shorter wavelength on adapted old lens, so it's not limiting in this case.
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