Adventures in de-yellowing (Pentax 67 SMC 104mm 2.4)

Jellygeist · 04-24-2018, 08:47 PM

Originally posted by chickentender

If it's any consolation, I never noticed a discernible difference on color films before and after. I wasn't doing direct comparisons of course, but if there was an effect, it was negligible.

I'll post some pics of my 6x7 work. I can see a definite warm cast to them, especially in skin tones. Though I'll let ye be the judge:

I've just never been satisfied with the colour rendition. I can see that the lens is yellow so I figure I'll go after that. I imagine that the lab that I was using wasn't giving it their all either but I'll fix the lens before I send it off to a different lab.

Eyewanders · 04-24-2018, 10:28 PM

Originally posted by Jellygeist

I'll post some pics of my 6x7 work. I can see a definite warm cast to them, especially in skin tones. Though I'll let ye be the judge:

I've just never been satisfied with the colour rendition. I can see that the lens is yellow so I figure I'll go after that. I imagine that the lab that I was using wasn't giving it their all either but I'll fix the lens before I send it off to a different lab.

Like I said, negligible.

You wont' know unless you a/b with a clear lens. And, even then...
Unless you're printing optically from negatives it doesn't matter. In my opinion. There is so much color variation that happens from capture, to processing, to scan, to import and then export to publish or print-file, every step adding it's own potential change or fix, for better or worse.

But I cleared mine... so....

(well I mostly cleared it - I got bored after a week and didn't bother any more. It was severely diminishing returns after the first 2 or 3 days.)

*But then I should say if you're just receiving scans done for you by the lab without any color-correction or editing of your own, then sure, makes sense.

Jellygeist · 04-26-2018, 09:10 PM

Originally posted by chickentender

Like I said, negligible.

You wont' know unless you a/b with a clear lens. And, even then...
Unless you're printing optically from negatives it doesn't matter. In my opinion. There is so much color variation that happens from capture, to processing, to scan, to import and then export to publish or print-file, every step adding it's own potential change or fix, for better or worse.

But I cleared mine... so....

(well I mostly cleared it - I got bored after a week and didn't bother any more. It was severely diminishing returns after the first 2 or 3 days.)

*But then I should say if you're just receiving scans done for you by the lab without any color-correction or editing of your own, then sure, makes sense.

Yeah, I hate doing post-processing aside from cropping. I can never get the colours right with the little sliders and I frankly don't care to learn. Not really my style or how I like to work, though I won't besmirch others for doing so.

Also, Amazon seems rather hesitant to ship my darn bulb. I thought we'd have drones doing this by now, totally eliminating both wait times and millions of delivery jobs causing great social unrest.

leekil · 04-26-2018, 11:17 PM

Originally posted by Jellygeist

Also, Amazon seems rather hesitant to ship my darn bulb. I thought we'd have drones doing this by now, totally eliminating both wait times and millions of delivery jobs causing great social unrest.

You win some, you lose some

Jellygeist · 04-29-2018, 03:01 PM

Originally posted by leekil

You win some, you lose some

"I have these short shipping times, but I got laid off from my job so I cannot afford any products or services!"

In other news, the bulb shipped.

Jellygeist · 05-01-2018, 07:47 PM - **1 Like**

Okay, update. I'll just leave this here for you to ponder:

jtkratzer · 05-02-2018, 05:39 AM - **1 Like**

Originally posted by Jellygeist

Okay, update. I'll just leave this here for you to ponder:

This is all I see:

Jellygeist · 05-02-2018, 08:13 AM - **1 Like**

Originally posted by jtkratzer

This is all I see:

You don't know the half of it, there's some Egon-level science nonsense going on in that tube. I was just gonna buy a cheap gooseneck lamp, but dad decided that cutting off the end of a Meta-Mucil tube, putting lugs on a light fixture and wiring it up to an extension cord, and then mounting the Death Bulb in the tube with aluminum foil on the outside would be a better option.

I was concerned with the wiring setting fire to our house, but dad knows what he's doing: 35 years in the electrical trade. I still had to yell at him not to put his gosh darn hand under the Death Bulb or not to look right at it.

Jellygeist · 05-02-2018, 04:33 PM

Okay, I checked the lens because it's been pretty close to 24 hours. Still yellow, but again...less than 24 hours. I flipped it over.

You folks have any ideas on timeframes? Some places say a few days, some say weeks.

**Alex645** · 05-02-2018, 06:17 PM - **1 Like**

Originally posted by Jellygeist

You folks have any ideas on timeframes? Some places say a few days, some say weeks.

It probably depends on how yellow the lens is and how intense the UV radiation. I'm guessing 3-10 days.

As clear glass will filter a lot of UV light, and the thoriated element is towards the back of the lens, do make sure that your lamp is directed at the rear element and don't flip it.

**rdenney** · 05-02-2018, 06:30 PM - **1 Like**

Patience. There's no deadline--you aren't trying to find the sweet spot between success and the glass vaporizing. Just leave it on and do other things. Come back to it in a week or two and see if there's improvement.

I have an old M42 SMC Takumar 50/1.4 that is going to get something like this as soon as you report success.

Rick "a watched pot never boils" Denney

Jellygeist · 05-02-2018, 07:51 PM

@Alex645 Ooooh yeah, that's true, I'll flip it back over.

@rdenney It's a darn good thing LEDs are so efficient and give off no appreciable heat. How did we ever live without them?

Jellygeist · 05-27-2018, 12:47 PM

Well, after a bit more than a month, I've decided to stop. I checked the lens every 3-4 days and any difference is quite slight.

Here are photos taken with the lens a few weeks ago. Keep in mind how awful the lighting was (that was the only day and time that worked for them and the sun refused to cooperate, hence the awful exposure)

What do you think?

**Alex645** · 05-27-2018, 01:06 PM

I think the Jets did great but just ran into a juggernaut with Vegas.

From your samples posted, it looks like there was some de-yellowing and improvement in contrast but not completely. With a bit more tweaking in post processing, you could probably improve it further.

When looking at the glass is there still a yellow tint?

Jellygeist · 05-27-2018, 03:45 PM

Originally posted by Alex645

I think the Jets did great but just ran into a juggernaut with Vegas.

From your samples posted, it looks like there was some de-yellowing and improvement in contrast but not completely. With a bit more tweaking in post processing, you could probably improve it further.

When looking at the glass is there still a yellow tint?

I'm actually kind of glad the Jets run is over. Now I don't have to follow sports anymore.

Yeah, it's not as intense but the tint is still there. The one of them in front of the pine tree isn't bad at all, given the overcast conditions.

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04-24-2018, 08:47 PM	#31
Jellygeist Veteran Member Join Date: Sep 2017 Location: Brandon, MB Photos: Albums Posts: 334 Original Poster	Originally posted by chickentender If it's any consolation, I never noticed a discernible difference on color films before and after. I wasn't doing direct comparisons of course, but if there was an effect, it was negligible. I'll post some pics of my 6x7 work. I can see a definite warm cast to them, especially in skin tones. Though I'll let ye be the judge: I've just never been satisfied with the colour rendition. I can see that the lens is yellow so I figure I'll go after that. I imagine that the lab that I was using wasn't giving it their all either but I'll fix the lens before I send it off to a different lab.

04-24-2018, 10:28 PM	#32
Eyewanders Veteran Member Join Date: Jan 2008 Location: Land of the Salish Sea Photos: Gallery \| Albums Posts: 3,343	Originally posted by Jellygeist I'll post some pics of my 6x7 work. I can see a definite warm cast to them, especially in skin tones. Though I'll let ye be the judge: I've just never been satisfied with the colour rendition. I can see that the lens is yellow so I figure I'll go after that. I imagine that the lab that I was using wasn't giving it their all either but I'll fix the lens before I send it off to a different lab. Like I said, negligible. You wont' know unless you a/b with a clear lens. And, even then... Unless you're printing optically from negatives it doesn't matter. In my opinion. There is so much color variation that happens from capture, to processing, to scan, to import and then export to publish or print-file, every step adding it's own potential change or fix, for better or worse. But I cleared mine... so.... (well I mostly cleared it - I got bored after a week and didn't bother any more. It was severely diminishing returns after the first 2 or 3 days.) *But then I should say if you're just receiving scans done for you by the lab without any color-correction or editing of your own, then sure, makes sense.

04-26-2018, 09:10 PM	#33
Jellygeist Veteran Member Join Date: Sep 2017 Location: Brandon, MB Photos: Albums Posts: 334 Original Poster	Originally posted by chickentender Like I said, negligible. You wont' know unless you a/b with a clear lens. And, even then... Unless you're printing optically from negatives it doesn't matter. In my opinion. There is so much color variation that happens from capture, to processing, to scan, to import and then export to publish or print-file, every step adding it's own potential change or fix, for better or worse. But I cleared mine... so.... (well I mostly cleared it - I got bored after a week and didn't bother any more. It was severely diminishing returns after the first 2 or 3 days.) *But then I should say if you're just receiving scans done for you by the lab without any color-correction or editing of your own, then sure, makes sense. Yeah, I hate doing post-processing aside from cropping. I can never get the colours right with the little sliders and I frankly don't care to learn. Not really my style or how I like to work, though I won't besmirch others for doing so. Also, Amazon seems rather hesitant to ship my darn bulb. I thought we'd have drones doing this by now, totally eliminating both wait times and millions of delivery jobs causing great social unrest.

04-26-2018, 11:17 PM	#34
leekil Pentaxian Join Date: May 2016 Photos: Albums Posts: 2,003	Originally posted by Jellygeist Also, Amazon seems rather hesitant to ship my darn bulb. I thought we'd have drones doing this by now, totally eliminating both wait times and millions of delivery jobs causing great social unrest. You win some, you lose some

04-29-2018, 03:01 PM	#35
Jellygeist Veteran Member Join Date: Sep 2017 Location: Brandon, MB Photos: Albums Posts: 334 Original Poster	Originally posted by leekil You win some, you lose some "I have these short shipping times, but I got laid off from my job so I cannot afford any products or services!" In other news, the bulb shipped.

05-01-2018, 07:47 PM - 1 Like	#36
Jellygeist Veteran Member Join Date: Sep 2017 Location: Brandon, MB Photos: Albums Posts: 334 Original Poster	Okay, update. I'll just leave this here for you to ponder:

05-02-2018, 05:39 AM - 1 Like	#37
jtkratzer Veteran Member Join Date: Jul 2012 Location: Lancaster County, Pa Posts: 963	Originally posted by Jellygeist Okay, update. I'll just leave this here for you to ponder: This is all I see:

05-02-2018, 08:13 AM - 1 Like	#38
Jellygeist Veteran Member Join Date: Sep 2017 Location: Brandon, MB Photos: Albums Posts: 334 Original Poster	Originally posted by jtkratzer This is all I see: You don't know the half of it, there's some Egon-level science nonsense going on in that tube. I was just gonna buy a cheap gooseneck lamp, but dad decided that cutting off the end of a Meta-Mucil tube, putting lugs on a light fixture and wiring it up to an extension cord, and then mounting the Death Bulb in the tube with aluminum foil on the outside would be a better option. I was concerned with the wiring setting fire to our house, but dad knows what he's doing: 35 years in the electrical trade. I still had to yell at him not to put his gosh darn hand under the Death Bulb or not to look right at it.

05-02-2018, 04:33 PM	#39
Jellygeist Veteran Member Join Date: Sep 2017 Location: Brandon, MB Photos: Albums Posts: 334 Original Poster	Okay, I checked the lens because it's been pretty close to 24 hours. Still yellow, but again...less than 24 hours. I flipped it over. You folks have any ideas on timeframes? Some places say a few days, some say weeks.

05-02-2018, 06:17 PM - 1 Like	#40
Alex645 Site Supporter Join Date: May 2015 Location: Kaneohe, HI Photos: Albums Posts: 3,526	Originally posted by Jellygeist You folks have any ideas on timeframes? Some places say a few days, some say weeks. It probably depends on how yellow the lens is and how intense the UV radiation. I'm guessing 3-10 days. As clear glass will filter a lot of UV light, and the thoriated element is towards the back of the lens, do make sure that your lamp is directed at the rear element and don't flip it.

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05-02-2018, 06:30 PM - 1 Like	#41
rdenney Site Supporter Join Date: Feb 2018 Location: NoVA Posts: 635	Patience. There's no deadline--you aren't trying to find the sweet spot between success and the glass vaporizing. Just leave it on and do other things. Come back to it in a week or two and see if there's improvement. I have an old M42 SMC Takumar 50/1.4 that is going to get something like this as soon as you report success. Rick "a watched pot never boils" Denney

05-02-2018, 07:51 PM	#42
Jellygeist Veteran Member Join Date: Sep 2017 Location: Brandon, MB Photos: Albums Posts: 334 Original Poster	@Alex645 Ooooh yeah, that's true, I'll flip it back over. @rdenney It's a darn good thing LEDs are so efficient and give off no appreciable heat. How did we ever live without them?

05-27-2018, 12:47 PM	#43
Jellygeist Veteran Member Join Date: Sep 2017 Location: Brandon, MB Photos: Albums Posts: 334 Original Poster	Well, after a bit more than a month, I've decided to stop. I checked the lens every 3-4 days and any difference is quite slight. Here are photos taken with the lens a few weeks ago. Keep in mind how awful the lighting was (that was the only day and time that worked for them and the sun refused to cooperate, hence the awful exposure) What do you think?

05-27-2018, 01:06 PM	#44
Alex645 Site Supporter Join Date: May 2015 Location: Kaneohe, HI Photos: Albums Posts: 3,526	I think the Jets did great but just ran into a juggernaut with Vegas. From your samples posted, it looks like there was some de-yellowing and improvement in contrast but not completely. With a bit more tweaking in post processing, you could probably improve it further. When looking at the glass is there still a yellow tint?

05-27-2018, 03:45 PM	#45
Jellygeist Veteran Member Join Date: Sep 2017 Location: Brandon, MB Photos: Albums Posts: 334 Original Poster	Originally posted by Alex645 I think the Jets did great but just ran into a juggernaut with Vegas. From your samples posted, it looks like there was some de-yellowing and improvement in contrast but not completely. With a bit more tweaking in post processing, you could probably improve it further. When looking at the glass is there still a yellow tint? I'm actually kind of glad the Jets run is over. Now I don't have to follow sports anymore. Yeah, it's not as intense but the tint is still there. The one of them in front of the pine tree isn't bad at all, given the overcast conditions.