|Lens brand & description||Nikon AF 75-240mm f/4.5~5.6D|
|Lens purpose||Low price zoom tele lens|
|Date tested||Oct/1999 on loan from Maxwells|
|Lens hood arrangement||Bayonet style HB-21 supplied with lens, stores reversed over lens body.|
|Focal lengths marked||75, 85, 105, 135, 200, 240mm|
|Lens construction||12 elements in 9 groups|
|Apertures marked||f/4.5 to f/32, camera LCD displays 4.5~32 @ 75mm, 5.6~45 @ 240mm|
|Aperture blades||7 with rounded aperture shape|
|Front rotate for focus/zoom||Front rotates with focus but not with zoom. Front extends for focus and for zoom.|
|Weight||415g bare, 485g with hood and caps.|
|Length Flange to front Min/Max & max diameter||No hood - min length 127mm, max length 173mm , diameter 72mm.
With hood - min length 190mm, max length 240mm , diameter 80mm
|Build quality comment||Has "Made in China" label. Plastic mount. Build quality looks good. Printing on lens may be easily subject to wear.|
|Closest focus from film plane & reproduction ratio||1.5m (4.9ft) RR about 1:4.8 at 240mm
Note: add closeup lens 6T on a 52-62mm stepup ring and nearly 1:1 can be achieved.
|Controls on lens||Aperture ring with min aperture lock, zoom ring, focus ring. No focus scales on lens.|
|Lens contact count||5|
|First Impressions||Nice and light, good feel, auto-focusses well, short throw for manual focus but works well, viewfinder brightness OK on F70 and N8008s but quite a bit dimmer on FE-10. Probably not a lens to use for night shots particularly on the FE-10 as it would be hard to see composition and check focus.Would make a nice cheap light travel lens. The hood supplied is very large and should provide good flare protection.|
The lens in question with the hood on and set to minimum length.
|Image Quality vs Aperture Chart||Max Aperture||Mid Aperture||Min Aperture|
|at 75mm||f/4.5 worst||f/11 best||f/32 middle|
|at 85mm||f/4.5 worst||f/11 best||f/32 middle|
|at 105mm||f/4.8 worst||f/11 best||f/32 middle|
|at 135mm||f/4.8 worst||f/11 best||f/32 middle|
|at 200mm||f/5.3 worst*||f/11 best||f/45 middle*|
|at 240mm||f/5.6 middle||f/11 best||f/45 worst|
* means extremely close decision. With all the rest the "worst" really means very close to the "best". The f/number is what I saw in the camera LCD panel. I would happily use this lens at any aperture but would choose f/8 to f/11 if wanting eventual enlargements.
Another test was to manually focus on some horizon scenery about a mile
away and shoot at every aperture for one set focal length on three lenses
all set to 180mm. The chart shows the order in which the quality was rated,
1 is best, 2 next and 3 worst image of the aperture comparison set.
|f/5||2||Slight light falloff to corners||1||No light falloff||3||Light falloff to corners|
|f/5.6||2||Very slight light falloff to corners||1||3||Slight light falloff to corners|
|f/8||2||Best aperture probably is at f/9.5||1||Probably best aperture||3||Very slight light falloff to corners|
|f/11||2||Very close decision||1||3||Probably best aperture|
|f/16||3||Extremely close decision||1||2|
|f/22||3||Extremely close decision||1||2|
|f/32||1||-||No equivalent aperture||-||No equivalent aperture|
The surprise seemed to be the performance on another test comparing the 75-240 with the Nikon AF 85/1.8D and the Nikon AF 180/2.8D ED-IF at 85mm and 180mm but focussed on detail at maybe 200 yards distance. It gave a slightly different result to the above set (at maybe a mile, careful manual focus). I didn't test all apertures on the next test, just at the widest aperture of the 75-240 and at f/11. The 85mm and 180mm lenses were also set to match the widest aperture of the 75-240 as well as f/11.
In that closer distance test it appears that the prime lenses are just
better than the zoom at f/11, it's very close and needs a magnifier on
the 6"x4" prints. But at the matching maximum aperture which was f/5 for
the 180mm test and f/4.5 for the 85mm, it works out that the 75-240 zoom
is just slightly better than the primes. Puzzling, but I've been over the
results many times, shuffling the prints and then inspecting and re-sorting
them into quality order then turning them over to see what was what. It
is very close but it always comes up the same.
I'm not so much learning how good this 75-240 lens is, as finding the weird things that happen at different focus distances. Something similar happened when testing the Nikon 80-200/2.8 (non-S version), it was second to the Sigma zoom on the one mile test but at portrait distances was better than the Sigma.
When you want to buy a lens you need to evaluate it at the distances you intend to use it at. OK, the differences were very slight but may make a difference if needing huge enlargements.
Nikon 75-240 lens at 240mm f/5.6 1/400 ISO 100 hand held.
I tried scanning at the maximum optical resolution of 600dpi on my flatbed but the detail cannot be captured successfully. Anyway what I was trying to talk about is the detail in the fence. Maybe it's about 6 or 7 feet high to stop people getting on the rail tracks. With a magnifier on the print it is easy to see the chain wire links in the fence and comparing the edges with the centre there is only a small amount of falloff in quality. In good daylight with the naked eye you can just detect there is a wire pattern at about 8 inches viewing distance on the 4"x6" print. I call this a good optical performance, that is, a lot more detail on the print than the eye can see normally.
Nikon 75-240 at 240mm at f/8 1/400.
I took two shots, one at maximum aperture and this one at f/8 when I shifted the program. That's why I like to use aperture priority normally, I get to chose a more sensible aperture than the camera chooses. The program seems to go to maximum apertures, I know I can hold a camera steady so I go for middle apertures and better quality and depth of field. As usual the scan looks drab beside the sharp and bright print.
Nikon 75-240 at 75mm at f/8 1/320
The shot above was another grab to see whether all the detail looks
good all over the frame and sure enough the actual print looks nice and
sharp all over. No light falloff to the corners like some lesser zooms
I've seen. I really don't know why I bother to scan and display these,
they don't do the situation justice at all.
The lenses comparison was between the Nikon 74-240 and the Sigma AF
75-300mm APO zoom (the good one, about vintage 1993), the Nikon AF 85/1.8D,
the Nikon AF 180/2.8D ED-IF at the appropriate focal lengths, the chart
should make sense, if not give me a yell and I'll make it clearer.
|At 75mm f/4.5||
|At 75mm f/11||
|At 85mm f/4.5||
|At 85mm f/11||
|At 180mm f/5||
|At 180mm f/11||
|At 240mm f/5.6||
|At 240mm f/11||
The 75-240 as a Macro lens.
Then for a macro comparison I put the Nikon 6T closeup lens on the 75-240mm using a 52-62 step-up ring and set it to minimum focus to get very close to 1:1 and compared it to the Nikon AF 105/2.8D macro lens at the same apertures, f/8 and f/22. If buying this lens then the sensible thing to do would be to get the Nikon 4T closeup lens (+2.9 dioptre double element) in 52mm size.
When zoomed to 240mm the image yielded was nearly 1:1 and the working distance from the front of the lens to the subject was about 270mm. This seems like a nice easy way to achieve macro. There was slight pincushion distortion, but not too disturbing and that would not be a problem if shooting a bug or flower. The image looked good from centre to edge. A lesser quality (single element) closeup lens would not yield as good an image. Of course the depth of field is the usual problem, but it's exactly the same shallow depth of field as with any macro lens. More tests on the same bank note and on a 3D object like an old watch innards look very much the same as the 105/2.8 macro except for the pincushion distortion.
Nikon 75-240 at 240mm at f/22 with 6T magnifier
The print image looks better than the scan as usual, note the slight
pincushion distortion along the top edge, the note wasn't placed properly
so the left side is a little higher in the frame. Not a combination for
serious flat work copying but would be great for general macro. There appears
to be no quality falloff to the edges. The width shown was the whole 4"x6"
print and measures 35mm of the actual bank note. The whole negative has
about another couple of millimetres of the subject thus making it very
slightly less than 1:1 on the film.
|Thanks for looking at this very early effort, there has been enough interest to cause me to put something here now before I have all the films back. Regards........... Guy|
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