800mm f6.3S PF Review - Thom Hogan

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I don't think Thom.is referring here to the AF fine tune issues like on the DSLRs. I have seen few of Thom's reviews of Z glass where he keeps saying there is focus shift when you stop the lens down and the fact that Z cameras do not have a way to correct it.
Exactly. Isn't his 400/2.8 TC supposed to be even more prone to focus shift?! It's a faster lens. It looks like Thom has some personal resentment about the 800pf. He did us all a favor and paid for a lens that he won't use because he doesn't need it. I'm reading all of his reviews, Its the first time he has written something like this.
Or, perhaps, that is his own way of getting "clicks".
 
In this the lens would normally focus wide open at f/6.3, and if you are trying to shoot at f/9 or f/11 you might find that the actual focus is different than wide open. I have not seen that, but technically it is possible. AF Fine tuning would not really be useful for this because the problem is not present wide open. My experience is I'm shooting wide open most of the time anyway, and the added DOF from stopping down should cover any focus shift issues.

Here is an article about focus shift.
sounds mostly hypothetical
 
Exactly. Isn't his 400/2.8 TC supposed to be even more prone to focus shift?! It's a faster lens. It looks like Thom has some personal resentment about the 800pf. He did us all a favor and paid for a lens that he won't use because he doesn't need it. I'm reading all of his reviews, Its the first time he has written something like this.
Or, perhaps, that is his own way of getting "clicks".
Not sure how he exactly measures this but here's one more from his review of the Z 24-70 f4 and I'm pretty sure I've seen this with few more of his reviews of Z mount lenses
"Focus shift: "
https://www.zsystemuser.com/z-mount...ion sharpeners.-,Focus shift:,-Some clear-but
 
Not sure how he exactly measures this but here's one more from his review of the Z 24-70 f4 and I'm pretty sure I've seen this with few more of his reviews of Z mount lenses
"Focus shift: "
https://www.zsystemuser.com/z-mount-lenses/nikkor-lenses/nikon-z-mount-lens-reviews/nikkor-24-70mm-f4-s-lens.html#:~:text=with deconvolution sharpeners.-,Focus shift:,-Some clear-but
This one of the lenses I never read because I was reading the 24-70 f/2.8 which I own.

How do you link a page down to the word?
 
Personally, i feel this topic on focus shift is a bit over rated. The issue allegedly crops when stopping down and the DoF will anyways take care of the focal plane.

Google has a feature wherein you can just select a portion of a text, a word, paragraph etc , right click and you'll see 'share'. Just copy and paste it and it'll link precisely to whatever you selected.

This one of the lenses I never read because I was reading the 24-70 f/2.8 which I own.

How do you link a page down to the word?

Do I need to be worried about focus shifting in the 50/1.2?
Isn’t Nikon aligning all the wavelengths before hitting the sensor?
 
The main reason he reviewed this 800mm is to complete his Z coverage, which is unmatched.... it's clear reading the introduction that Nikon fast tracked getting a copy to him - a factor that's disclosed up front. He works every lens hard before finalizing his review. Kudos to Thom and obvious benefits to photographers.

The additional focal length aka 'Reach' is extremely useful across a range of scenes/subjects with a 800mm; so is the tighter 2.5o field of view - compared to 5o for a 400 and ~3.4o of a 600 on FX ['o' should be in superscript = degree symbol). Compared to my experience the costs of this tighter FoV is over dramatized IME. I find it naieve to pigeonhole all wildlife photographers into a context where they should be closer in on subjects. Moose Peterson is one who's raved about his 800 f5.6E, ever since he bought his in early 2014 and still uses it often apparently (however Moose P sure is enthusiastic about his gear!). However, Steve and many here deeply appreciate the advantages of not only 800mm but 1120mm and even 1600mm in FX format. Most importantly we have the images as proof of principle.

On the niggling subjects, I do agree with Thom that Nikon's engineers got button layout almost right on the 100-400 S but they slipped up on their placement in the other Telephoto Z primes. The buttons on the 800 PF would work much better closer together.

Compared to a 400 f2.8E + TC2 III and latterly a 800 f5.6E (even on support) I continue to be impressed with the unexpectedly excellent VR of the 800 PF. This is one most important feature of the 800 PF that's not highlighted that often, and Thom H leaves out this VT (by the way). The anti-shakes technology in this Zed super telephoto probably reflects on the combination of IBIS with the Z VR, but I've captured challenging keepers in poor light , which have been a pleasant surprise.... 1/125 and 1/200 handheld for example.

Bottom line, together with the 400 f4.5S. As much has been said, and is being said many times.... Kudos to Nikon for enabling this new PhaseFresnel model relatively affordable and combining ergonomics with such impressive acuity. The engineers ticked all the boxes with this Z Nikkor

Of note: "The design concept of this lens is that amateurs can also use it for shooting, so we use a low-cost high-performance STM stepper motor. In addition, the focus group has been optimized from the design stage, allowing the STM stepper motor to fully demonstrate its performance."
 
Across such subjects and scenes, a 800 prime is impressive in its versatility. Soon after its first outings, it was beyond doubt the ZTC14 added even more bang-for-$ to this 800 PF... some examples: https://bcgforums.com/index.php?thr...r-african-mammals-and-birds.17190/post-191231

IMHO I've proved the abilities conferred by a 800mm lens apply as much to frame a large mammal in a portrait at tens of metres; as they do to capture an Animalscape at approx hundred metres.... And equally as handholding using field skills enables spying on a small mammal or bird within ~10m away, and in each case frame the subject appropriately. This chunky Vlei-Rat was munching away unconcernedly ~7m from where I was crouched, and I captured many frames in waning light at dusk. I kept turning down the shutter speed and a surprising percentage are sharp
Otomys irroratus nibbling_F Cotterill-7012.jpg
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Common Vlei-Rat, Otomys irroratus 1/250 ISO6400 Nikon Z9, 800 f6.3S PF
 
On the niggling subjects, I do agree with Thom that Nikon's engineers got button layout almost right on the 100-400 S but they slipped up on their placement in the other Telephoto Z primes. The buttons on the 800 PF would work much better closer together.
i have a suspicion that control placement is a secondary consideration. i get the impression nikon has a vision for the role each lens will fill and then is taking an almost artisanal approach to building the lens completely driven by that goal and other performance characteristics are higher on the list than control consistency or layout.

as an example folks have commented on the lack of display on the 85 1.2 and suggested possible reasons like weight or cost savings. my guess would be more that it just didn’t fit well into that space with this design and instead of adding bulk or compromising the design they just didn’t include it. of course it could also be they noticed most of us simply didn’t seem to care about the display that much.
 
...Compared to my experience the costs of this tighter FoV is over dramatized IME...
I completely agree with this. To repeat what I said above FOV is FOV regardless of focal length. If you are filling the frame with a subject it's just as hard to track motion with 400mm as it is with 500, 600, 800... And in fact it's easier with longer lenses due to increased distance and therefore slower relative motion. The reason this is perceived as such an issue is because from a practical standpoint most wildlife photographers seek longer glass because they aren't/can't getting close enough to fill the frame and look to longer glass to do so. In which case yes certainly shooting from the same distance and going from 500mm to 800mm keeping a BIF in the frame is going to be harder.

... I find it naieve to pigeonhole all wildlife photographers into a context where they should be closer in on subjects...
We should keep in mind that Thom is NOT a wildlife photographer. For a few days each year he sits in the back of a safari vehicle in Africa. With animals well habituated to vehicles he can simply tell the driver to get him closer. This is also no doubt the reason that he makes such an issue of heat distortion. Virtually all of his wildlife shooting is done in Africa and he shoots a lot of sports over sun heated fields(or pitches in the Queen's English). My frame of reference is the exact opposite. The vast majority of my shooting is in overcast condition, low sun angles, or over water. I can count on fingers the number of times heat distortion has been a practical concern for me.


This thread(myself included) has been a lot of discussion about the (minor)negative things Thom had to say in spite of his ultimately giving the lens his "highly recommended" rating. But we can't unsee things. Now that I'm aware of the focus shift issue it's ruined it for me. I think I'll sell mine :rolleyes:
 
On the matters of subject size(s) and 'filling the frame' , I collated this schematic as a field guide. It is clear why it's not uncommon to find that a 800mm lens on a FX camera barely suffices for smaller birds. In these situations, one often needs 1120mm to frame a tiny bird at a ~5m distance.

Medium sized mammals are another example: e.g. smaller antelopes, warthogs, cats about lynx size etc. When hiking, I have found 700mm is too little lens to frame Caracal that are relatively approachable if one is discrete. One male I met up with a few times once stalked me as I was lying down in camouflage, but although curious he still kept safe distance for himself. Since that lesson I never leave the house with the 800 PF without the TC14.

1678448808670.png
 
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To repeat what I said above FOV is FOV regardless of focal length. If you are filling the frame with a subject it's just as hard to track motion with 400mm as it is with 500, 600, 800... And in fact it's easier with longer lenses due to increased distance and therefore slower relative motion.

I think geometry might disagree with this statement...

If you are tracking a subject from a fixed position you are roughly moving in a circle, twisting your body as you are trying to keep the bird in frame.

Now, if my napkin math is correct, at 16m you'll get the same FOV with an 800mm as you'd get at 10m with a 500mm.
So shooting with the 500mm you are in the center of a circle with a radius of 10m => roughly 62m circumference.
Shooting with the 800mm you are in the center of a circle with a radius of 16m => roughly 100mm circumference.

So, say, if you twist 10 degrees to follow the bird, you would have shifted your image by 1.7 meters with the 500mm and 2.7m with the 800mm (remember, FOV is the same).

Since humans aren't precision instruments (most of us at least), this means that, for the same FOV it is harder to make precise adjustments and easier to overshoot your subject with the 800mm than the 500mm.

So it is realistically harder to track with the 800 :D

Also, as a fun fact, since keeping the FoV the same means you are further away from your subject with the 800mm and since air temperature is not uniform over distance and this leads to refraction of the light beam that leads to loss of sharpness, you can end up with more light bends when using the 800mm than the 500mm pf so the longer lens is more impacted by heat distortion...
 
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Personally, i feel this topic on focus shift is a bit over rated. The issue allegedly crops when stopping down and the DoF will anyways take care of the focal plane.

Google has a feature wherein you can just select a portion of a text, a word, paragraph etc , right click and you'll see 'share'. Just copy and paste it and it'll link precisely to whatever you selected.
But when I do shoot wide open? Or I’m a at MFD with a stopped down lens?
Is this a real issue with Nikon (or all) lenses, or not? I’m asking seriously.
 
But when I do shoot wide open? Or I’m a at MFD with a stopped down lens?
Is this a real issue with Nikon (or all) lenses, or not? I’m asking seriously.
I don't think it's a real issue, but if it exists it is when you are stopped down beyond f/5.6. The Z lenses normally focus at an aperture of f/5.6 (this is not exactly true, but close enough). Thom may see it but especially with the Z cameras, I'm not sure I buy it. There are only so many issues you can worry about.

I can tell you I did not see it in any of my images while testing at MFD and wide open.
 
I think geometry might disagree with this statement...

If you are tracking a subject from a fixed position you are roughly moving in a circle, twisting your body as you are trying to keep the bird in frame.

Now, if my napkin math is correct, at 16m you'll get the same FOV with an 800mm as you'd get at 10m with a 500mm.
So shooting with the 500mm you are in the center of a circle with a radius of 10m => roughly 62m circumference.
Shooting with the 800mm you are in the center of a circle with a radius of 16m => roughly 100mm circumference.

So, say, if you twist 10 degrees to follow the bird, you would have shifted your image by 1.7 meters with the 500mm and 2.7m with the 800mm (remember, FOV is the same).

Since humans aren't precision instruments (most of us at least), this means that, for the same FOV it is harder to make precise adjustments and easier to overshoot your subject with the 800mm than the 500mm.

So it is realistically harder to track with the 800 :D

Also, as a fun fact, since keeping the FoV the same means you are further away from your subject with the 800mm and since air temperature is not uniform over distance and this leads to refraction of the light beam that leads to loss of sharpness, you can end up with more light bends when using the 800mm than the 500mm pf so the longer lens is more impacted by heat distortion...
Most certainly for anyone whose challenge to keep the image in the VF is shaky hands etc the longer lens is harder. If the challenge is movement of the animal it is easier the farther away that you are. Put away the calculator and try it you'll like it ;)

Regarding the heat distortion no argument as you describe it. And that's the argument Thom uses. My whole point above is that most people seeking longer glass are not in control of distance to subject and will be shooting the same distance regardless of focal length. Therefore no difference in heat distortion. Not sure why anyone would spend funds to get 800mm if they can simply get closer. If that was the case I'd still be content shooting the old 300mm f4D and could have saved thousands.
 
On the matters of subject size(s) and 'filling the frame' , I collated this schematic as a field guide. It is clear why it's not uncommon to find a 800mm lens on a FX camera barely suffices for smaller birds. In these situations, one needs 1120mm to frame a tiny bird at a ~5m distance.

Medium sized mammals are another example: e.g. smaller antelopes, warthogs, cats about lynx size etc. When hiking, I have found 700mm is too little lens to frame Caracal that are relatively approachable if one is discrete. One male I met a few times once stalked me as I was lying down in camouflage, but he was still maintained a safe distance for him. Since that lesson I never leave the house with the 800 PF without the TC14.

View attachment 56483
I love this chart that you created. When do you plan to publish the North America version? :)
 
[...] At a given distance from the subject and for the same field of view(i.e. final cropped image) heat distortion has the same effect regardless of lens used. As he mentions many people are buying this lens because they can't get any closer to what they're shooting and they want more "pixels on target". So regardless of what lens they use heat distortion is going to be the same. [...]
Don't forget that the effects of heat distortion are pretty much enlarged by a 800mm lens compared to a short lens, in the same way the subject appears enlarged on the sensor.
Indeed, at a long distance, the air between you and the subject is the same, but I have never heard any photographer complaining about heat distortion when shooting mountains with a 28mm lens.
 
Don't forget that the effects of heat distortion are pretty much enlarged by a 800mm lens compared to a short lens, in the same way the subject appears enlarged on the sensor.
Indeed, at a long distance, the air between you and the subject is the same, but I have never heard any photographer complaining about heat distortion when shooting mountains with a 28mm lens.
You must not have read the post carefully. You either overlooked, ignored, or misunderstood the part about "for the same field of view(i.e. final cropped image)".
 
On the matters of subject size(s) and 'filling the frame' , I collated this schematic as a field guide. It is clear why it's not uncommon to find that a 800mm lens on a FX camera barely suffices for smaller birds. In these situations, one often needs 1120mm to frame a tiny bird at a ~5m distance.

Medium sized mammals are another example: e.g. smaller antelopes, warthogs, cats about lynx size etc. When hiking, I have found 700mm is too little lens to frame Caracal that are relatively approachable if one is discrete. One male I met up with a few times once stalked me as I was lying down in camouflage, but although curious he still kept safe distance for himself. Since that lesson I never leave the house with the 800 PF without the TC14.
Nice chart! Wish our bobcats would wander over and check me out! Maybe I should rub myself with fish oil? I find I never have enough reach so I carry both the 1.4 and 2.0 TC with my 800mm lens. Allows me to stay at a distance and watch them hunt, etc (of course, then someone else approaches them and spooks them).
Recent shot at 1600 mm:
[ ]
 
I love this chart that you created. When do you plan to publish the North America version? :)
Thank you. I drew it up in Coreldraw, using clipart icons and also a font set depicting some African animals. But the birds are Chicken, Pigeon, Sparrow I think so more global citizens! I was aiming at extremes in diversity as a rough guide to gauging distances etc. The distances are computed using an online site. I carry this on longer trips printed as a "cheatsheet" with DoF tables etc

Nice chart! Wish our bobcats would wander over and check me out! Maybe I should rub myself with fish oil? I find I never have enough reach so I carry both the 1.4 and 2.0 TC with my 800mm lens. Allows me to stay at a distance and watch them hunt, etc (of course, then someone else approaches them and spooks them).
Recent shot at 1600 mm:
[ ]

Thank you.

Interesting. IME, and from reading, wild cats are challenging to get close to on foot. Being so alert is obviously key to their survival living alongside the most destructive species on Earth and their commensal domesticates, notably dogs. Lion are one exception in the very few places where they they still survive.
A couple of times I've found lions truculent on meeting up but typically they just want to carry on with their siesta or eating etc. If wary they retreat during daylight if treated with due respect, but they can be dangerously cheeky at night... As once when I was engaged in nighttime fieldwork studying bats - treed by lions for most of the night (until they departed at dawn); such that I empathize ever since with baboons forced to sleep in trees :D
In contrast I've managed only once photographing a leopard while walking over in many years:)
Caracal along on the periurban fringe habitats in the Western Cape have become more habituated, compared to decades back. I shared a photo of a memorable encounter.
 
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