300mm f/4.5 ED-IF AI Nikkor on D850...

[David H. Hartman]

This is a quick and dirty test of my 300/4.5 ED-IF AI Nikkor on my D850. The D850 is brutally intolerant of focus errors with this lens. This lens exhibits purple-magenta blooming of harsh spectacular highlights. The problem is visible even in thumbnails. It seems largely correctable in Capture NX-D. Lateral color aberration correction, on by default, seems to soften the central image slightly so I turned it off. [Yes but Lateral Color Aberration correction helps at the edge so I turned it back on]. An Axial Color Aberration setting of 50 or more is helpful. The following are samples of the center image without then with an Axial color aberration setting of 70. This test is a worst case scenario.

I hope some find this test useful. A less demanding test subject failed as I blew the focus. 

Dave

I just noticed that right click, "View image" and clicking the image shows the image at full resolution, 1:1 pixels.

The following are f/4.5 without and then with Axial color aberration correction followed by f/8.0 without and then with Axial color aberration correction. The JPG(s) were creates as 100% pixel images...

[Jack Dahlgren]

Wow, that first photo looks like magic.

[David H. Hartman]

Unless I'm loosing my mind one set I shot had worse purple blooming at f/5.6 compared to f/4.5 and f/8.0. That doesn't make sense. I ran out of time to do anymore test shots.

My thinking is I can use this lens with my Nikon D850 provided I stop down a stop or so, use Axial Color Aberration correction as needed and especially if I avoid pixel peeping.

I don't care I'll just float a check

Cause I'm feelin' my gamblin' Jones

Here come seven, gimme eleven come again

Love to hideout where I am my own best friend

Critical focus will be a crap shoot! 

Did I mixed up the games?

Dave

[Snoogly]

Wow, that first photo looks like magic.

Reminds me a lot of some special effects in Star Trek series one.

[David H. Hartman]

I turned Lateral Color Aberration correction back on because it helps at the edges. I probably knew that in a past life. 

[David H. Hartman]

Reminds me a lot of some special effects in Star Trek series one.

Now that I think of it the purple blooms look like the blossom of a common variety of ice plant found around So. California.

[Gil Aegerter]

Wonderful lens, though!

[David H. Hartman]

Wonderful lens, though!

It was designed for film. Then again my test was pretty much a worse case scenario. If like me a photographer doesn't have any other 300mm lens them know the weakness of the lens and work around it.

Dave

[David H. Hartman]

Is this test valid? Was I testing my 300/4.5 ED-IF AI here or my D850? I'm able to produce similar purple "flowers" with my 400/5.6 ED AI and 135/2.8 AIS. I can even get a hit of this purple fringing with my AF-S 50/1.8G Nikkor.

The light is off the pond now and I'm bird sitting. Maybe in a few days I'll get some samples and start a new topic.

Dave

[Erik Lund]

Purple / Magenta Fringing or Blooming is a combination of lens and sensor - I recall we have discussed this subject before,,,
 
https://nikongear.net/revival/index.php?topic=3374.msg49029#msg49029
 
Here 400mm f/5.6 and similar

https://nikongear.net/revival/index.php?topic=569.msg4328#msg4328

One way to correct Raw files is PhotoNinja

[David H. Hartman]

So far I can mostly correct the purple fringing with Nikon Capture NX-D's Axial Color Aberration and Lateral Color Aberration tools and I presume NX Studio when it's debugged enough for use. Other software from other makers can do the same. Now my understanding is the purple fringing happens when the image sensor is over-loaded and there is a sharp divide between bright and dark. At this point it doesn't seem useful to test lenses for purple fringing under such extreme conditions as it will surely be found.

Dave

[Erik Lund]

Some camera/lens combinations don't exhibit purple fringing in the above situation.

[David H. Hartman]

Is purple fringing the work of the devil? 

[Erik Lund]

Yes - Digital Devil 

[David H. Hartman]

Some camera/lens combinations don't exhibit purple fringing in the above situation.

I can confirm this observation as I just tested my 105/4.0 AI Micro-Nikkor on the waterfall and found not a trace of purple fringing at f/4.0 and f/8.0. 

Perhaps the old test of thin tree branches against a bright sky is less severe, more useful? Anyway the severe purple fringing seen in the 300/4.5 ED-IF AI test above was almost corrected (satisfactory) in the f/4.5 sample and completely corrected in the f/8.0 sample using Capture NX-D's Axial color aberration tool. This is after all pixel peeping so I'm feeling better about using the 300/4.5 ED-IF on my D850. If I can manage to nail the focus with the 300/4.5 ED-IF the results at f/8.0 are great.

Dave