UV Filters - Let's Get Empirical: These were shot as identically as possible. So, let's see if one can tell the difference between using or not using a UV filter. When it was used, it...

rmalarz Loc: Tempe, Arizona

These were shot as identically as possible. So, let's see if one can tell the difference between using or not using a UV filter. When it was used, it was a B+W Pro-F filter. The rest of the information is contained in the EXIF data. The images were opened in ACR no adjustments were applied. Opened in Ps and saved as jpg format images, again no adjustments were made.

The idea is whether or not a difference is visually noticeable. It doesn't really matter which was taken with or which without.
--Bob

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rwm283main Loc: Terryville, CT

#2 photo visually has a slightly warmer tone to it. It also looks slightly sharper (looking at each one downloaded and blowing them up a bit). All based on viewing them using my iPhone.

DirtFarmer Loc: Escaped from the NYC area, back to MA

rmalarz wrote:

These were shot as identically as possible. So, le... (show quote)

I believe comparisons are best done with a blink test. Accordingly, I have made a gif that switches back and forth between the two images. You can see that there is motion of the branches between the two shots, probably a slight breeze.

I also took the two images in Photoshop and subtracted them. The result was pretty dim so I applied a curves layer and pulled the white point from 255 down to 20. Most of the difference shows up at the edges, which is not surprising given the motion.

PS: You have to use Download to see the motion on the gif.

To avoid the motion you'd probably have to do this indoors. However, then you'd lose the UV in sunlight. You might be able to do it with fluorescent lighting, which depends on UV to activate the phosphors, but you'd have to be careful to use a shutter speed that was a submultiple of the line frequency to avoid temporal color shifts.

Blink test
Blink test...

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Image Difference
Image Difference...

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rmalarz Loc: Tempe, Arizona

rwm283main , thank you both for your replies. Yeah, a cell phone may not be the best method of viewing these.

Dirtfarmer, a good involved process but, alas, a slight breeze interferes with trying to do these types of comparisons. Perhaps a plain Macbeth color chart photographed with and without would be a better approach.
--Bob

Rongnongno Loc: FL

rmalarz wrote:

rwm283main , thank you both for your replies. Yeah, a cell phone may not be the best method of viewing these.

Dirtfarmer, a good involved process but, alas, a slight breeze interferes with trying to do these types of comparisons. Perhaps a plain Macbeth color chart photographed with and without would be a better approach.
--Bob

Actually, the simpler approach is to use averaging.

Visually? Toss a coin.

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kpmac Loc: Ragley, La

Not much difference on my monitor, Bob.

DirtFarmer Loc: Escaped from the NYC area, back to MA

I really recommend creating a gif to see the difference. Using Photoshop, it's a breeze (weak pun intended). You can see differences without having to shift your focus between different images. If you don't use Photoshop, there are other ways to produce a blink test.

I see some tonal changes in some of the petals, but they could be due to shading differences between exposures with the image elements in slightly different positions. Other than that I don't really see any significant difference that would be visible to the naked eye.

rmalarz Loc: Tempe, Arizona

That's pretty much my observation, Ken.
--Bob

kpmac wrote:

Not much difference on my monitor, Bob.

Rongnongno Loc: FL

This reminds me of this:

Select one.

The window was made in china.
The fly was made in germany.

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rmalarz Loc: Tempe, Arizona

DF, the same observation difference here, slight, most likely due to the small breeze. Definitely not enough to declare filters degrade a photograph. When I did this test this morning I was prepared to make comments either way, yeah filters a bad, or can't see a discernable difference. At least it will provide visual evidence that filters degrade an image to rest. But, then again, there are those that seem to enjoy arguing.
--Bob

DirtFarmer wrote:

I really recommend creating a gif to see the diffe... (show quote)

Rongnongno Loc: FL

This thread gave me an idea on how to create a luminosity mask...

Longshadow Loc: Audubon, PA, United States

rmalarz wrote:

These were shot as identically as possible. So, le... (show quote)

I put each image it its own tab and flipped back and forth for minutes looking at different areas of the image.
I would put the difference as between none and barely noticeable.
I'd say nada...
Thanks!

Bill_de Loc: US

Me thinks we all have too much spare time on our hands.

Did anybody really think there would be discernable different results?

If there were discernable results, would it make you remove your filter.

Inquiring minds, and the mindless, all want to know.

Enjoy the weekend.

User ID

Rongnongno wrote:

This thread gave me an idea on how to create mask...

(Download)

Longshadow Loc: Audubon, PA, United States

Bill_de wrote:

Me thinks we all have too much spare time on our hands.

Did anybody really think there would be discernable different results?

If there were discernable results, would it make you remove your filter.

Inquiring minds, and the mindless, all want to know.

Enjoy the weekend.

ME thinks that some people are too persnickety and minutia oriented.

I knew there would not be a discernible difference.
But, but, but there is an added piece of glass and it has a coating......

Yea, they do.

You also.