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The best way to capture the front and rear coatings on a len
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PostPosted: Sun May 22, 2016 2:48 am    Post subject: The best way to capture the front and rear coatings on a len Reply with quote

I have a few pancolar 2/50 lenses,from the various batches produced (I still have quite a few too collect) and I want to capture the true color of the glass and or its coating.Do any of you have a fool proof way of doing this?or have any pointers/techniques of how I can get a true representation of the coating on each lens?

When I look at each lens, some I could say are blue and some yellow but then there are some that look mixed. Basically I don't trust my own eyes Smile.
Thanks for any help.


PostPosted: Sun May 29, 2016 11:51 pm    Post subject: Reply with quote

Set white balance using white card -- include white card in frame...

Multiple lenses one photo is easier for me to compare differences than separate photos of each lens.


PostPosted: Mon May 30, 2016 5:32 am    Post subject: Reply with quote

Like 1 small Like 1 small Like 1 small


PostPosted: Tue May 31, 2016 4:31 am    Post subject: Reply with quote

visualopsins wrote:
Set white balance using white card -- include white card in frame...

Multiple lenses one photo is easier for me to compare differences than separate photos of each lens.


So you mean take the photo with each lens, not an image of each lens surface...never thought of that Smile Would any type of subject be of more benefit in the photo?


PostPosted: Tue May 31, 2016 4:57 am    Post subject: Reply with quote

Well was thinking about a photo of a piece of photo paper with the lenses arranged on top, each positioned best to display coating "color". In post processing, use white balance tool, click on photo paper.


PostPosted: Tue May 31, 2016 10:52 pm    Post subject: Reply with quote

Ah ha, thanks for clearing that up,I am not at all familiar with photo paper and not really sure where I will find some (I guess somewhere on ebay) Sorry I am a bit dense but I appreciate the help as I want to do this as best I can.


PostPosted: Wed Jun 01, 2016 11:00 pm    Post subject: Reply with quote

And here I was thinking there'd be a piece of photo paper nearby. Laughing

That's what I use -- clever, eh? -- to set white balance same as paper that will be used for printing...

Well, maybe not so clever...

The idea is to get something reasonably white in the frame so it can be clicked with white balance tool in pp. Copy paper works. A white card. This will give accurate color to the coatings in the resulting photo. But that isn't really necessary for comparing coating colors of multiple lenses in a single photo... To get even more accurate color, try the Gretag-MacBeth color system -- it sets white balance for a number of colors, accounting for sensor sensitivity variation for different colors -- that's what Orio was using...

You're not dense! Laughing There's only some noise on the line...


PostPosted: Thu Jun 02, 2016 4:33 pm    Post subject: Reply with quote

visualopsins wrote:
And here I was thinking there'd be a piece of photo paper nearby. Laughing

That's what I use -- clever, eh? -- to set white balance same as paper that will be used for printing...

Well, maybe not so clever...

The idea is to get something reasonably white in the frame so it can be clicked with white balance tool in pp. Copy paper works. A white card. This will give accurate color to the coatings in the resulting photo. But that isn't really necessary for comparing coating colors of multiple lenses in a single photo... To get even more accurate color, try the Gretag-MacBeth color system -- it sets white balance for a number of colors, accounting for sensor sensitivity variation for different colors -- that's what Orio was using...

You're not dense! Laughing There's only some noise on the line...


I would not use a white, but rather slight grey, to avoid burnt out white all over and WB on that BG.


PostPosted: Sat Jun 04, 2016 3:21 am    Post subject: Reply with quote

Thanks for the advice from both of you,it really is appreciated.It won't happen that quickly but it will happen eventually.


PostPosted: Sat Jun 04, 2016 3:47 am    Post subject: Reply with quote

My biggest problem photographing lenses is with reflections -- lens photos made outdoors among the fir trees makes the lenses appear fungus filled. Laughing


PostPosted: Sat Jun 04, 2016 11:58 am    Post subject: Reply with quote

Some reflections on the glass make for a more interesting image.


PostPosted: Sun Jun 05, 2016 9:49 pm    Post subject: Reply with quote

There is the experimental approach. Nobody knows what you may learn using that method!


PostPosted: Tue Jun 07, 2016 8:15 pm    Post subject: Reply with quote

mo wrote:
Some reflections on the glass make for a more interesting image.


Yes! Smile Those reflections revealing the lens optical formula can be interesting indeed! I use a 1-led torch.

Managing to capture all that AND the lens name ring AND the distance scale showing the lens minimum focus distance -- the perfect all-in-one lens photo? Laughing


PostPosted: Sat Jun 18, 2016 4:51 pm    Post subject: Reply with quote

The reflections of point-source light from each element can be different color. This is also seen in images exhibiting colorful lens flare.


PostPosted: Sun Jun 19, 2016 6:20 am    Post subject: Reply with quote

i think I have read about this,I have tried to count the reflections I see.Is there a failsafe way to count these light source reflections? Or is it a case of trial and error,too see which angle you shine it into the lens works the best.


PostPosted: Sun Jun 19, 2016 11:19 am    Post subject: Reply with quote

You can start with those lenses with known design. For example, a Tessar 50/2.8 with will show four reflections in front of the aperture if you view the lens from the front and three reflections in front of the aperture(one of them is a weak reflection from the cemented surface) if you view the lens from the back. For a Primoplan 58/1.9, you will see three reflections(one of them is a weak reflection from the cemented surface) in front of the aperture and four reflections in the back of aperture. You can find a list of lens diagrams here(there may be errors in the diagrams but most of them are correct) http://forum.mflenses.com/list-of-lens-diagrams-triplets-planars-and-hybrid-lenses-t22934.html .

Try to look at the reflections from difference angle. In my experience, my table lamp is better than a point light source. Use a magnifier or take a photo when it is hard to tell from naked eyes.


PostPosted: Wed Jun 22, 2016 10:48 pm    Post subject: Reply with quote

Thanks Calvin,I have both those lenses so will compare too see if what I am looking at is the right reflection Smile