Why are f4 and f5.6 super telephoto lenses so poor in resolution and contrast?

[spotmeter]

When I was shooting with my Canon 5D2, I noticed that my Canon 400mm f5.6 had very poor resolution and contrast compared to the Canon 200mm and shorter lenses.

Now that I am shooting with the Nikon D800E, I see that LensRentals found the Nikon 300mm f4 to have low resolution when tested on the D800.  Its MTF chart confirms this.

Why are these small aperture super telephotos so poor?

I can understand that a wide angle lens can be difficult to design because the light rays have to be bent so much. But with the narrow angle of a telephoto, the light rays are almost parallel and require much less bending.

From experience and looking at MTF charts, it seems the best telephoto lenses are in the 85mm to 135mm range.  Unless you are willing to buy a $6,000 behemoth and lug it around, it seems you can't get a decent super telephoto that is reasonable in price and weight.

[stever]

i have no such issues with the 400 f5.6 on a 5D2 or 5D3.  have not used the really long lenses - which from all reports are excellent, but have found the 300mm primes to be excellent.  my only lack of satisfaction is with the 100-400 (my copy is better than expected on FF) and the 400DO.

the only issue with the 400 f5.6 is lack of IS which requires 1/1000 for sharp hand-held images or careful tripod use limiting its general usefulness

[Ellis Vener]

The Nikon 300mm f/4 is a very old design, basically dating from the late or mid-nineties. Why they have not updated it blows my mind. Here's another not very flattering review of it here by Bjorn Rorslett from 2000. Bjorn knows Nikkor lenses as well as anyone inside or outside of Nikon: http://nikongear.com/live/index.php?/page/index.html/_/nikon-reviews/300mm-f4g-ed-if-af-s-nikkor-r36

[spotmeter]

Thanks, Elis.

This confirms Nikon's own MTF chart for the 300, which is surprisingly poor.

My Canon 400mm has poor resolution and contrast compared to the Canon 135mm and 200mm.

What could be the technical problems designing such a lens that prevents manufacturers from making a great lens in this focal length?

Any optical physicists on this forum?

[Ellis Vener]

Thanks, Elis.

This confirms Nikon's own MTF chart for the 300, which is surprisingly poor.

My Canon 400mm has poor resolution and contrast compared to the Canon 135mm and 200mm.

What could be the technical problems designing such a lens that prevents manufacturers from making a great lens in this focal length?

Any optical physicists on this forum?

I suspect there are no optical problems, just marketing and demand ones.  On one end there  is a lot of demand for 300mm f/2.8 lenses and on the other a lot of demand for zooms that reach 300mm. That makes a single focal length 300mm f/4 kind of an orphan.

Perhaps as cameras like the 5D Mark III, 1D X, D3s, D4 and D800 gett better better and better at high ISO settings maybe the  smaller and lighter weight 300mm f/4 will come back into its own, even for mirrorless interchangable lens cameras.
 

[Brian Hirschfeld]

Certainly for walking around I prefer the 300mm f/4. I was having some more serious health problems when I went to Bali last year, and I had to rent a 5D Mrkii and a few lenses, because I needed a compromise on weight and functionality which I couldn't get with any of my stuff. D3s, far to heavy, Phase out of the question, Leica, yeah no because I wanted to do some wildlife, and wanted AF camera. So it was a logical choice. I took the 35mm f/1.4, 50mm f/1.2 and 300mm f/4 and couldn't have been happier with it.

I found it was very good optically, and had no issues with the images that I was making handheld.....it is light and it works. I would be willing to bet a fixed 300mm would have better quality then a 100-400 on either Nikon and Canon, and it is prob lighter and better AF no?

No experience with the 400mm f/5.6 but I would be willing to bet it might be worse since its basically the 300mm f/4 with a TC built in...

[telyt]

I suspect there are no optical problems, just marketing and demand ones.

The Leica 280mm f/4 APO suggests the problem is marketing and demand.

[spotmeter]

Certainly for walking around I prefer the 300mm f/4. I was having some more serious health problems when I went to Bali last year, and I had to rent a 5D Mrkii and a few lenses, because I needed a compromise on weight and functionality which I couldn't get with any of my stuff. D3s, far to heavy, Phase out of the question, Leica, yeah no because I wanted to do some wildlife, and wanted AF camera. So it was a logical choice. I took the 35mm f/1.4, 50mm f/1.2 and 300mm f/4 and couldn't have been happier with it.

I found it was very good optically, and had no issues with the images that I was making handheld.....it is light and it works. I would be willing to bet a fixed 300mm would have better quality then a 100-400 on either Nikon and Canon, and it is prob lighter and better AF no?

No experience with the 400mm f/5.6 but I would be willing to bet it might be worse since its basically the 300mm f/4 with a TC built in...

I was talking about the 300mm for the Nikon D800E, and yes these lenses are fine for hand held and walking around, but I shoot on a tripod, mirror locked up and with the much higher resolution D800E because my prints are 5 to 10 feet long.  Even the MTF for the Nikon 300 is very poor, especially compared to their 85 and 100mm lenses.

[spotmeter]

The Leica 280mm f/4 APO suggests the problem is marketing and demand.

What is it about the Leica lens that suggests it's marketing and demand?

[ErikKaffehr]

Hi,

The main problem with telephoto lenses is lateral chromatic aberration. Lateral chroma is not affected by aperture, so the only rescue is low dispersion glass, which used to be expensive. So they use ED glass or even CaF2 (Calcium Flouride) for some elements in expensive lenses. On economical lenses they use cheaper glass.

Best regards
Eik

When I was shooting with my Canon 5D2, I noticed that my Canon 400mm f5.6 had very poor resolution and contrast compared to the Canon 200mm and shorter lenses.

Now that I am shooting with the Nikon D800E, I see that LensRentals found the Nikon 300mm f4 to have low resolution when tested on the D800.  Its MTF chart confirms this.

Why are these small aperture super telephotos so poor?

I can understand that a wide angle lens can be difficult to design because the light rays have to be bent so much. But with the narrow angle of a telephoto, the light rays are almost parallel and require much less bending.

From experience and looking at MTF charts, it seems the best telephoto lenses are in the 85mm to 135mm range.  Unless you are willing to buy a $6,000 behemoth and lug it around, it seems you can't get a decent super telephoto that is reasonable in price and weight.

[Ellis Vener]

All versions of the Nikon 300mm f/4 lenses all have at least one ED glass element in them.

[telyt]

What is it about the Leica lens that suggests it's marketing and demand?

It's a very sharp high contrast lens, very close to diffraction-limited at full aperture.

[Ellis Vener]

It's a very sharp high contrast lens, very close to diffraction-limited at full aperture.

And cost well over $2,000 when available. Note: Leica has discontinued the R line of cameras and lenses.

[telyt]

And cost well over $2,000 when available. Note: Leica has discontinued the R line of cameras and lenses.

I paid $1600 for mine in 2004.  The current market value suggests some demand for this level of performance, even without the conveniences of AF and IS or VR.  Regardless of the price the performance of this lens demonstrates that high resolution and high contrast is possible in a lens of this speed and focal length.  Whatever their reasons, CaNikon have chosen not to produce a comparable high-performance lens.  There's no technical reason they can't.

[WaitingForAnR10]

When I was shooting with my Canon 5D2, I noticed that my Canon 400mm f5.6 had very poor resolution and contrast compared to the Canon 200mm and shorter lenses.

Now that I am shooting with the Nikon D800E, I see that LensRentals found the Nikon 300mm f4 to have low resolution when tested on the D800.  Its MTF chart confirms this.

Why are these small aperture super telephotos so poor?

I can understand that a wide angle lens can be difficult to design because the light rays have to be bent so much. But with the narrow angle of a telephoto, the light rays are almost parallel and require much less bending.

From experience and looking at MTF charts, it seems the best telephoto lenses are in the 85mm to 135mm range.  Unless you are willing to buy a $6,000 behemoth and lug it around, it seems you can't get a decent super telephoto that is reasonable in price and weight.

I'm not seeing any problems with my 5DII and 800/5.6 shot at wide open.

[telyt]

I'm not seeing any problems with my 5DII and 800/5.6 shot at wide open.

And it's not a $6000 behemoth either 

[Ray]

I also wonder about this issue. If Nikon had produced a sharp 80-400/5.6 or 100-400/5.6 or 150-400/F5.6 with VR2, I would have been prepared to pay a modest premium, and would also have bought their D3200.

I suspect the real reason why they don't offer such a lens is not because it cannot be designed, but because such a lens would reduce the sales of their very expensive and very heavy F2.8 and F4 primes of 400mm and greater.

[NancyP]

Nothing wrong with a good copy of Canon 400mm f/5.6L, in focus, shot at high shutter speed or on a tripod. It is best at f/5.6 and f/8, less crisp at f/16, but then again I shoot APS-C, so that is expected. 99% of the time I shoot at f/5.6.

Is there an issue of poor autofocus, and would there be a need for AF microadjustment for some of you?