A story of old and new lenses

[ianwatson]

From all indications given by the various members about this lens, it will not doubt, not disappoint. Admittedly, despite what Mongo thought about the impracticability of having both lenses, he now thinks if you end up with both through fortuitous  circumstances, it gives you some real choice

I am looking forward to your thoughts after you have had the chance to compare them.

[Frank Fremerey]

Thanks again for the added advice.

Well, the unthinkable has happened. One of our members chanced into a camera shop 4000 kilometres away across Australia and saw a great looking used 20mm f1.8. He was kind enough to send Mongo a PM about this. Mongo contacted the store this morning and purchased what appears to be a near mint copy of the lens for a ridiculously low price. Used copies in Australia are almost non-existent. For that amount and condition, it was a no brainer - just bought it and now have the option of going either way after a good opportunity to assess it.  It should arrive in 2 days.

A very sincere thanks for all your advice and input with this decision.
No one could have predicted what happened in the last 24 hours.

let it check at NPS for decentering. After some experience with used and even with new glass and centering issues for me this has become standard procedure

[Mongo]

Jack, have not had good results with polarisers on digital but will try it on this 20mm f1.8 in case things have changed.

Ian, may give some views about this lens after a good trial period

Frank, have a lot of new and used gear. Only buy pristine used gear. Must say, have never had a problem with used gear but have had a lot of trouble with new gear. Will see how this lens looks and performs. If any doubt, can send it back or have Nikon look at it. Mongo assumes "NPS" is nikon ??

[Akira]

Jack, have not had good results with polarisers on digital but will try it on this 20mm f1.8 in case things have changed.

Ian, may give some views about this lens after a good trial period

Frank, have a lot of new and used gear. Only buy pristine used gear. Must say, have never had a problem with used gear but have had a lot of trouble with new gear. Will see how this lens looks and performs. If any doubt, can send it back or have Nikon look at it. Mongo assumes "NPS" is nikon ??

Hmm...my humble understanding is that PL doesn't work evenly on the lenses whose focal lengths are 24mm and wider.

NPS stands for Nikon Professional Service.  My rate of grabbing factory defect samples are fairly high.     So, I always have my newly purchased lenses to check at Nikon.  The correctly assembled and/or adjusted AF-S lenses don't need the AF fine tune function in the camera.

[armando_m]

Mongo,
I think you will enjoy the lens, you may remember I own the 20 f1.8 AFS, it is a fun lens and it never dissapoints me

An example image taken without looking through the viewfinder


It is very useful on any situation, still I bought mostly for astrowork


Both images shot at f1.8

[Akira]

Mongo,
I think you will enjoy the lens, you may remember I own the 20 f1.8 AFS, it is a fun lens and it never dissapoints me

An example image taken without looking through the viewfinder


It is very useful on any situation, still I bought mostly for astrowork

Both images shot at f1.8

Oh, I love this blue-footed boobies image!  Thank you for posting it again!

[Frank Fremerey]

Mongo,
I think you will enjoy the lens, you may remember I own the 20 f1.8 AFS, it is a fun lens and it never dissapoints me

An example image taken without looking through the viewfinder


It is very useful on any situation, still I bought mostly for astrowork


Both images shot at f1.8

I remember these shots an I really really like them

[pluton]

Hmm...my humble understanding is that PL doesn't work evenly on the lenses whose focal lengths are 24mm and wider.

It's not that the Pola filter doesn't work evenly, it's that the darkening of the blue sky due to polarization is not evenly distributed over the entire hemisphere of the sky.
The polarized portion of the sky is a ring whose plane sits at 90º to the sun-viewer axis. Find the sun, look 90º away from the sun, and you'll be looking at the most polarized portion of the sky.
At sunrise or sunset, the ring is straight above.  At high noon, the ring sits at the horizon, 360º around you.
The ring, or zone of maximum polarization, is roughly 30º-40º across. The field of view of a wide angle lens is much more likely to see beyond the polarized zone than a narrow angle lens.
 

[Seapy]

Keith, I am shaking my head in disbelief!

The things I learn here unexpectedly, are beyond my wildest expectations.  Thank you for such a concise and understandable explanation.

Are you able please to explain the difference, as related to photography between circular and 'normal' polarising filters?  I understand circular is a requirement for digital but linear for film, I can't understand why they should be different.

[Jack Dahlgren]

It's not that the Pola filter doesn't work evenly, it's that the darkening of the blue sky due to polarization is not evenly distributed over the entire hemisphere of the sky.
The polarized portion of the sky is a ring whose plane sits at 90º to the sun-viewer axis. Find the sun, look 90º away from the sun, and you'll be looking at the most polarized portion of the sky.
At sunrise or sunset, the ring is straight above.  At high noon, the ring sits at the horizon, 360º around you.
The ring, or zone of maximum polarization, is roughly 30º-40º across. The field of view of a wide angle lens is much more likely to see beyond the polarized zone than a narrow angle lens.
 

How is this different on digital than it was on film? I am familiar with the limitations, but seemed like Mongo said they didn't work as well with digital cameras and I'm trying to understand why.
I suppose with digital post processing you can more easily modify the sky if you want.
However, I find them interesting in the way they knock down reflections - this can have big effect in saturating the colors of foliage.

[Roland Vink]

... At high noon, the ring sits at the horizon, 360º around you...

In this situation, it is possible to use a polarizer on even the widest lens and get even polarization of the sky from edge to edge. The polarizer nicely cuts through the haze near the horizon, while the sky higher up is less affected by polarization but is a deeper blue anyway, so the effect looks even top to bottom. I regularly used a polarizer on my 20mm lens (and I'd use it on my fisheye if I could!)

Even when the sun is lower and the band of maximum polarization arcs up into the sky opposite, the polarizer can still be used effectively with some care, depending on how you frame the sky, and whether you adjust the polarizer so the sky is fully or only partially polarized. It's only when you get a dark band of polarized sky running down the middle of the image that it doesn't really work. So I don't believe it when people say that you can't use a polarizer on wide lenses, you have to judge each scene on its merits.

The effect is the same with film and digital, but in my experience, polarizers results in a strange loss of contrast on digital that I never found on film, even on the best multi-coated filters. I suspect digital sensors are more reflective than film, so reflections from the polarizing foil itself (sandwiched between the glass) may be the cause.

[pluton]

However, I find them interesting in the way they knock down reflections - this can have big effect in saturating the colors of foliage.

Yes, I neglected to mention the non-sky-darkening uses of polas.  They still work for refections within the standard acceptance angles.  They can be very effective for eliminating the glossy shine from leaves.

[pluton]

The effect is the same with film and digital, but in my experience, polarizers results in a strange loss of contrast on digital that I never found on film, even on the best multi-coated filters. I suspect digital sensors are more reflective than film, so reflections from the polarizing foil itself (sandwiched between the glass) may be the cause.

I've also noticed this. I am thankful in those situations that digital allows quick and effective contrast adjustment.

[Jakov Minić]

Armando, never look through the viewfinder again!

I always thought that the extra thin B+W MRC circular polarizers could be mounted on wide angle lenses. I didn't know of the 24mm rule. I have one that I used to use on my 17-35/2.8 but I cannot verify or substantiate whether there is any loss when shooting wider than 24mm.

[Akira]

Keith and Roland, thank you very much for explaining detailed behavior of PL filters.

I always wondered why Cheyco Leidmann, one of my favorite photographers, even used a specially made PL for his 13mm/f5.6 Nikkor lens!:

http://cheycoleidmann.blogspot.com/search/label/14-Tec

Armando, never look through the viewfinder again!

I didn't know of the 24mm rule. I have one that I used to use on my 17-35/2.8 but I cannot verify or substantiate whether there is any loss when shooting wider than 24mm.

LOL!

Jakov, the 24mm-rule that I've heard of might to be meant as a very general advice for the total beginners.