In my review of the Nikon 500mm f/5.6 PF, user Marceli commented that the Imatest scores for the 500mm f/5.6 + Nikon 1.4x TC III were similar to the score for the Nikon 800mm f/6.3 S lens, which we’ve also reviewed. Given this, does it still make sense to the get the 800mm f/6.3 if you already have the 500mm f/5.6? Rather than leave a quick response for Marceli in the comment section, I wanted to give a complete answer that examined all the considerations at play. That’s what I’ll be doing today.
To start, here are the two Imatest scores for these two lenses:
As you can see, in the shared aperture range from f/8 to f/16, the Nikon Z 800mm f/6.3 is sharper throughout the frame, but it’s close enough that I see why Marceli asked me the question. And you don’t gain sharpness on the 800mm PF by shooting it wide open at f/6.3 – you actually lose a bit.
So, some photographers might wonder whether it’s worth it to get the Nikon 800mm f/6.3 when they can use the cheaper 500mm f/5.6 PF with the TC III instead. However, this is one case where even identical lab test results (which these definitely aren’t) would be deceiving, and where the Nikon 800mm f/6.3 S is the better choice for several reasons.
The first is that the 500mm f/5.6 + 1.4x TC III only gives you 700mm, not 800mm. That’s a 1.15x crop factor, which looks like this:
Already, this crop factor favors the Nikon 800mm f/6.3. But that’s not all. The 800mm f/6.3 has a maximum aperture of f/6.3, whereas the 500mm f/5.6 + 1.4X TC III is at f/8.
You can have a really sharp lens, but in a dim environment, every extra bit of light-gathering ability helps retain more information from what little photons there are left. The difference from f/6.3 to f/8 is two-thirds of a stop, which is definitely significant. But don’t take my word for it. I took the following photos at f/8 and f/6.3 with corresponding differences in ISO:
I turned on default denoising for both. You can see that in the f/8 image, there is already a lot more chroma and luma noise, making the details less apparent. In real-world conditions when you need every bit of detail on those beautiful bird feathers, this difference will be even more significant – especially when you add it to the 800mm vs 700mm difference.
Then there’s the consideration of focus speed. The best Nikon mirrorless cameras are pretty good at autofocusing with an f/8 lens, but it’s definitely a struggle in low light. Using f/6.3 instead of f/8 can make a massive difference to focus speed – and if your subject is moving quickly, that also means accurate focus.
As for other differences, the bare 500mm f/5.6 is pretty good when it comes to chromatic aberrations, but fringing begins to climb with the teleconverter. There’s also the fact that on the Nikon Z system, you’ll be using a teleconverter plus an FTZ adapter on the 500mm f/5.6. That’s three total lens mounts stuck together – not very ergonomic, and potentially more concerning if there are any alignment issues.
All told, the benefits of the 800mm f/6.3 really add up in this comparison: the longer focal length, wider maximum aperture, better focusing, slightly higher Imatest score (at a given aperture), and lower chromatic aberrations. If I needed good image quality and maximum reach, the 800mm f/6.3 is clearly preferable to the 500mm f/5.6 PF + 1.4x TC – both in bright conditions and particularly if you’re shooting at anything above base ISO.
Conclusion
As a long-time fan of the Nikon 500mm f/5.6 PF, I don’t want to make this comparison sound like I hate the lens – exactly the opposite! It’s probably my all-time favorite lens. When shooting at 500mm, it is just as good as $5000+ exotic supertelephotos in image quality, and it does pair surprisingly well with the 1.4x TC III if you need 700mm in a pinch.
That said, the 500mm + 1.4x combo is not on the same level as the Z 800mm f/6.3 for gathering maximum detail on the most distant subjects. Yes, lab sharpness is reasonably close, but the reality in the field includes other considerations. The 800mm’s extra reach, better low-light focusing, and brighter maximum aperture – plus the sharpness advantage in the shared aperture range – all lead me to one conclusion: The Nikon Z 800mm f/6.3 is the better choice every time for shooting at or near 800mm on the Z system.
Of course, when it comes to shooting at 500mm, then it’s a different story… which is why, if you are deciding between these two lenses, just get the focal length that you are more likely to shoot with the bare lens!
Regarding the choice between the 800pf and the 500pf+1.4tc options, if budget is not a constraint for you, the 800pf is indeed a strong choice. The point being made was that while the 800pf comes at a higher price, the difference in image quality compared to the 500pf+1.4tc may not justify the additional cost.
What about shooting the 500pf with tc on a dx dslr like d7500, that would save me the cost of buying a z camera and also save me money on the used 500pf lens
It’s a good choice but the focus accuracy of the 500PF on a DSLR drops when the TC is added. Personally, I don’t like TCs and I’d just use the bare lens on a DSLR.
As someone who owns both lenses, the sharpness conclusions of the 800mm you have come to don’t make sense to me as it is certainly not what am seeing. The 500 is incredibly sharp but I’ve found the 800mm to be noticeably sharper. I don’t own the 1.4 TC but I think I might pick one up to test the 500 and compare against the 800.
I would certainly be interested in the test, but I know a lot comes down to real-world conditions, which body you use the lens on, subjects you have at the time, etc. And of course if you are comparing side-by-side then the 800 still has that slight additional crop factor which does count too.
While I can appreciate a prime does better than a lens with a teleconverter on it, since I already have the 500 PF and 1.4 TC I will not be buying the 800 PF any time soon!
There is of course also the weight difference! The idea in this post was to emphasize that there are just too many other factors besides sharpness when you are deciding between the two. And also, under real-world conditions, both lenses are so sharp that you shouldn’t really consider numbers, but rather which one is overall more appropriate for the conditions at hand.
I agree, I still have a Sigma 800 f5.6 I can use if I really need 800mm, but if you are talking about weight, that thing weighs 4.7kg! Clearly not even close to the 800 PF!
Hi Jason!
Thanks for complete answer!
I understand Your conclusion – its very logical and definitely right. I agree with You in all aspects.
But…
I confused about how “weak” 800 PF is…
Its new lens, he should “destroy” 500 PF with TC 1.4 III (I write about sharpness, other things like f6.3 to f8 are obvious).
I read all tests and comparisions on photographylife.com, and I do often private comparisions.
And…
always, always prime lens in same class with TC (even 1.4) is noticeable weaker then lens without TC (usually at borders). In my comparisions – i see the same situation.
But not in this situation.
Its strange for me.
Another story.
I compare my 500 FL + TC 1.4 III with 800 PF, and lens with TC was a noticeable sharper then 800 PF.
Im expected they will be comparable in sharpness, or 800 PF win a little. No.
Ok, I can understand it – lenses is not in same class.
Jason, once again, thanks for Your answer!
Marceli
I think partly, this may be a case where it’s a little harder to design an 800mm compared to a 500mm. To make the 800 “as sharp” (in the sense of scoring the same on a test like this) as a 500mmm might have made it even more expensive.
I also remember reading on Nikon’s website that the 500pf was designed with the TC in mind, so maybe that’s why it is still decent with it, more so than you might expect.
Jason, Its possible.
But in this situation – overall differences between 500 PF + TC 1.4 III and 800 PF, are more subtle then I expected.
Only for me, of course.
Yes, I remember information about TC too.
I will ask You by the way.
All lens sharpness tests on photographylife.com – with new graphic line – are comparable?
Yes, all of them are!
Regarding: getting feather details.
To get such details, one has to be fairly close to the bird. My question is: how close for both lenses?
Say you are photographing a Grey Owl, wings tucked in, sitting on a perch, in very good diffused light. So, ideal conditions to capture feather details.
So, how far away from the owl would you be – for both lenses, framing the bird the same way, on the same full frame camera body?
I ask because I do not own a telephoto lense, and this information would be good to know before purchasing an expensive lense.
I’ not sure, but I think it calculates as this:
to compensate for a 2x crop factor you have to be half the distance. so if you fill the frame with a 800mm at 25m distance, you’d have to be 12,5m at 400mm.
The 800 vs 700 is a crop factor of 800/700=1.15. So you’d have to be at 25m/1.15=21.7m.
same with 800 vs 500. crop factor: 800/500=1.6. So you’d have to be at 25m/1.6=15.6m.
I’ll happily be corrected if that is wrong.
Thanks for the answer Mario. I think you are correct in your mathematics. But will you get “great feather details” from 15m/20m away from the bird?
What about atmospheric conditions and pollution?
If the subject is framed the same way for both lenses, the 800mm lense will result in more haze.
If one is willing to sneak up on the subject, say in a hide, then one might as well get the 500mm lense and sneak up a bit more.
Well, if you use the 500PF vs 800PF on the same camera, and sneak up closer with the 500PF to get the same framing, then yes indeed, the 500PF shot will be superior with the caveat that the perspective will be different.
Hi Jason,
Many thanks for your in depth and interesting article here.
I wish you extend your review to D500 paired with 500mm PF F5.6 lens without TC as compared to mirrorless Z8 or Z9 body paired with 800 mm F6.3. The two combinations are very identical in term of focal length and max apeture. It will be interesting to see how the new generation of Z bodys compete with older generation D500.
Hope to hear from you soon.
Cheers.
In terms of field of view, they are identical. But the Z8 and Z9 have the same pixel density as the D500, so there is no additional reach provided by the D500 over the Z8/Z9…hence with a 500PF, the Z8/Z9 will give the same result as the D500 *when cropped*…thus, the Z8/Z9 + 800PF will provide a 1.6**2 = 2.25 as many pixels on target compared to the D500 + 500PF.
In terms of light gathering ability, the Z8+800PF will crush the D500+500PF in low light, IF you had both combos side by side, shooting the exact same subject with those similar framings, with the caveat that the 500PF on the D500 will be a bit less tight due to the 8/7 crop factor.
SO, in terms of pure IQ, the Z8/Z9 + 800PF will be better than the D500+500PF most of the time, when you are comparing them *with the same framing*.
Of course, in the real world, using a 500PF on a D500 or an 800PF on a Z8 will result in *very* different pictures, simply because in the real world there is a lot more to consider in terms of field of view. They are not always comparable.
However, what we can say is that the 500PF on the Z8/Z9 will be just as good or better than the D500 + 500PF in *every* case, simply because of equal pixel densities. It will be better when you don’t have to crop, since you can’t “uncrop” a D500 shot.
The 800PF is more specialized, and will beat the 500PF in those cases where you get the right framing. In terms of birding, the framing you get is by chance a lot of the time.
Thus, whether the 800PF is right for you over the 500PF depends on circumstance, availability of shooting locations, etc. From my own experience birding and seeing almost 700 species of birds and photographing most of them, I’d say that the 500PF is the more general and versatile lens, whereas the 800PF is more specialized. It’s not a general-purpose lens compared to the 500PF but it will shine in the right conditions, and when it does, it is far more suitable that the 500PF, even if you slap a TC on it.
New Z8 and 800mm = £10,000.
Used D500 and 500mm (750mm efl) = £3,3,00 (approx).
Might be the deciding factor?
Many thanks again for your reply Jason.
When it comes to bird photography, of course additional focal length is a great advantage in getting the best shot. Hence Z8 paired with 800mm PF would be an advantage. I have been using D500 paired with 500mm PF (without TC) for bird photography for the past 4 years. I must say I am happy with the results thus far, except for the burst rate is far too slow as compared with Z8 or Z9 body especially shooting bird in flight. Hence, I do not find a good reason for upgrading my current gear, let alone the price.
I use the same! D500 + 500PF, without the TC. Good enough for me!
There are several advantages of the Z8/Z9 bodies over the D500 besides the frame rate. No mirror black out, it’s lots easier to keep a bird in the frame with FX rather than DX, no mirror slap or shutter shock. Since buying the Z9 I haven’t used my D500, even though it’s still a great camera.
As far as the 500PF on a Z body, I don’t like using a TC in addition to the FTX II. Even though they mount up snugly enough, the combination feels loose.
I have both the 500PF and the 800PF. Honestly, in my informal testing of the 500PF with and without the TC14E II and III, it was very difficult to see a difference between images taken with the bare lens and cropped to match those taken with either TC.
I haven’t bothered testing the 500PF + TC vs the 800PF.
I forget, the price of 500 mm PF is 3700 E, both being unattainable from the price point point of view.
Yeah, the 800mm f/6.3 is more expensive, but not by double or anything like that. The 500mm f/5.6 combo (with the 1.4x TC + FTZ II adapter) is $4350, and the 800mm f/6.3 is $6500 in the US. Used prices favor the 500mm more than that, though.
I think n-o one knows a sitation where a TC improves the sharpness of a lens. The problem is how big is the the loss of the sharpness. Another problem is the price of this 800 mm ,here, being 7400 E.
no one ,not n-o one
Yes, I sincerely doubt a TC could make a lens sharper than it is bare, for sure! That would be cool though.