Reach = (16/25 x 10/6 x 630/750) 2 x 1.0 => 80 % detail 7of benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1=1.0.
Reach = (16/25 x 10/18 x 750/500) 2 x 0.8 => 50 % detail of benchmark picture.
CLight x CAtm x CLens x CSensor = 0.9 x 0.9 x 1 x 1 = 0.8.
Reach = (16/25 x 10/25 x 2000/750) 2 x 1.0 => 200 % detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Overall splendid result with top quality Swarovski telescope, solid Panasonic mirrorless G3 and high quality 20mm 1.7 lens. Perfect detail, great colour depth (shades blue black!) and high light contrast (and lots of patience !)at relatively short distance of an extremely shy bird.
Reach = (16/25 x 10/21 x 1260/750)² x 1.25 => qqq % of detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1.25 x 1 x 1 = 1.25
Size smaller, distance shorter, equivalent large. Marvellous result with high quality Tamron 600mm and modern D500 sensor. Great detail (feathers, feet, nails), good colour depth (shades blue) and beautiful light and colour contrast at relatively short distance. Onluy few seconds to make the shot through bushes and branches at the very moment this Kingfisher took a short brake at this spot which we had anticipated.
Reach = (16/25 x 10/28 x 1500/500)² x 1.25 => 45 % of detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1.25 x 1 x 1 = 1.25
Rich detail of relatively small bird. High quality sensor Z50 and aspherical TC-20E III converter, large equivalent, Lightroom editing, evening sunlight and exceptionally clean atmosphere created perfect contrast and colour depth.
Reach = (16/25 x 10/28 x 1500/500)² x 1.25 => 40 % of detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1.25 x 1 x 1 = 1.25
Good detail of relatively small bird. High quality sensor Z50 and, great aspherical TC-20E III converter, large equivalent, Lightroom RAW conversion and editing and exceptionally clean atmosphere created good detail in this picture in spite of the cloudy wheather. This example clearly shows that also in cloudy wheather one can acquire detailed pictures. Size, distance and equivalent are governing factors, irect sunlight will improve light and colour contrast in a picture but usually does not add substantial detail.
Reach = (16/25 x 10/28 x 1500/500)² x 1.25 => 40 % detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1.25 x 1 x 1 = 1.25
Reach = (16/25 x 10/25 x 1620/500) 2 x 0.8 => 50 % detail benchmark picture.
CLight x CAtm x CLens x CSensor = 0.9 x 1 x 1 x 1= 0.9
Extremely dark cloudy rainy midwinter wheather (original RAW picture below). This affects resolution. J5 uses more or less the same sensor as D500 with great low light performance.
This RAW converted non edited picture after Lightroom editing produces surprisingly good detail considering circumstances. Look at edited picture 8 at birds eye, white neck and nails in this very dark rainy windy midwinter wheather!
Reach = (16/25 x 10/32 x 1050/500)² x 1.25 => 50 % detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1.25 x 1 x 1 = 1.25
Exceptionally clean atmosphere roughly compensates larger distance.
By the way: This picture became our Standard picture effect of “Exceptionally clean atmosphere“. We always keep this result in mind as a standard reference: this is about the maximum hoevver significant effect of exceptionally clean atmosphere: only a bit more detail but far better colours and colour contrast and visibly more vibrance in the picture!
Reach = (16/25 x 10/33 x 1050/500) 2 x 1.25=> qqq % detail benchmark picture. If you stretch the Kingfisher to about 3/4 of this total picture the amount of detail/mm2 will degrade too much.
CLight x CAtm x CLens x CSensor = 1 x 1.25 x 1 x 1 = 1.25
Size smaller, distance larger, equivalent significantly larger than in benchmark picture, resulting in about half the resolution of the benchmark picture, although overall surprisingly satisfactory result with the pro quality Nikkor 500mm, a really great lightweight telelens. Particularly birds feet have perfect detail.
As you can see: one gets significant difference in the amount of detail of the same bird at for example 27 meter and 33 meter. This is the quadratic effect of the Reach-formula at work: 272 = 729 and 332 = 1090, rounded: 730 and 1100! In bird photography a few meters distance can make a “mile” of difference in amount of detail! Plus or minus 10 % distance translates into substantially leeser respectively more detail in bird pictures!
By the way: This picture over time became our Standard picture “BORDERLINE CASE distance 33 meter Kingfisher, equivalent 1050mm, sun, exceptionally clean atmosphere“. This is about as far as you can reach with 1050mm equipment and this size of bird in sunlight and percectly clean air.
Reach = (16/25 x 10/33 x 1500/500) 2 x 1.25 => qqq % detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1.25 x 1 x 1 = 1.25
Reach = (16/25 x 10/33 x 1050/500) 2 x 1.25 => 25 % detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1.25 x 1 x 1 = 1.25
Size smaller, distance quite large, equivalent significantly lower than benchmark picture, resulting in about about a quarter of detail of the benchmark picture. This result is surprisingly satisfactory with high quality Z7 sensor and pro quality Nikkor 500mm, our wonderful favourite lightweight telelens.
Reach = (16/25 x 10/40 x 1500/500) 2 x 1.25 => 25 % detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1.25 x 1 x 1 = 1.25
Size smaller, distance larger, equivalent significantly larger than benchmark picture, resulting in about half resolution benchmark picture. Nevertheless overall surprisingly satisfactory result with pro quality Nikkor 500mm and great aspheric converter TC-20E III, both great lightweight optics.
This amount of detail though is rather low. If you would stretch the Kingfisher to full frame height the amount of detail would degrade way too much. Nevertheless we really do like this very picture and experience it as quite satisfactory. For example the amount of detail of bird’s feet and nails at 40 meter is extraordinary! The exceptionally clean atmposphere obviously has significant effect in this situation. Maybe we should account for it using factor 1.35 in stead of 1.25 but we will leave it at that. This is an estimate, not an exact calculation.
| Test pictures various bird Sizes S cm |
Reach = (15/25 x 10/6 x 375/500)² x 1.0 => 75% amount detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Rather small bird close by, low equivalent but this surprisingly high quality Z zoomlens is deliveriing constant rich detail and colour depth. Other bird photographers do confirm this. Nikon is offering this lens for an attractive price as kitlens Z50.
Reach = (14/25 x 10/6 x 1050/500)² x 1. 0 => 400 % amount detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Reach = (17/25 x 10/8 x 1050/500)² x 1.0 => 250 % detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Rather small bird, extremely short distance, high quality equipment and direct sunlight result in marvellous detail and colour depth.
Reach = (17/25 x 10/8 x 1050/500)² x 1.0 => 250 % detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Good detail with pro quality Nikkor 500mm and high quality D500 sensor. Average large bird tather close.
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@dik check and update yet
Reach = (16/25 x 10/33 x 1050/500) 2 x 1.25=> 50 % detail benchmark picture. If you stretch the Kingfisher to about 3/4 of this total picture the amount of detail/mm2 will degrade too much.
CLight x CAtm x CLens x CSensor = 1 x 1.25 x 1 x 1 = 1.25
Size smaller, distance larger, equivalent significantly larger than in benchmark picture, resulting in about half the resolution of the benchmark picture, although overall surprisingly satisfactory result with the pro quality Nikkor 500mm, a really great lightweight telelens. Particularly birds feet have perfect detail.
By the way: This picture over time became our Standard picture distance 35 meter Kestrel, equivalent 1500mm, sun. This is about as far as you can acquire a very well detailed mrr orless framefillg picture using thos equipment having 1500mm equivalent and this size of bird in direct sunlight and clean air.
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CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Reach = (22/25 x 10/302 x 150o/500)2 x 1.0 => qqq amount of detail benchmark picture. So this bird fits quite well in the picture frame.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Reach = (35/25 x 10/252 x 150o/500)2 x 1.0 => qqq amount of detail benchmark picture. So this bird fits quite well in the picture frame.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
@dik replace
Reach = (90/25 x 10/15 x 1500/500)2 x 1.0 => qqq % amount of detail benchmark picture. The bird covers almost the entire picture frame.
@dik move to action
We noticed the bird landing in a deep ditch about 50 yards away and approached carefully so the Heron did not see us on our camouflaged tribike. Our approach took about 10 minutes and the bird was not disturbed but Fter a wgilw took off spontaneously and flew quite relaxed away so we could shoot a few pictures when it was passing by.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Rather small bird, extremely short distance, high quality equipment and direct sunlight result in marvellous detail and colour depth.
Reach = (17/25 x 10/8 x 1050/500)² x 1.0 => 75 % detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
@dik dehaze fg qm
Reach = (17/25 x 10/8 x 1050/500)² x 1.0 => 250 % detail benchmark picture. qqq qm qqq
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Rather small and shy mediterranan bird short distance, high quality equipment and direct sunlight produce perfect detail and colour depth.
Reach = (25/25 x 10/10 x 630/450)² x 1.0 => 1.4² => 200% amount detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
The larger equivalent, using a 1.4 converter. results in exactly twice (1.42 = 2) the amount of detail. Sunlight in the actual situation compared to cloudy wheather in the benchmark usually results only in more light contrast and more colour contrast but does not necessarily add more detail so we kept all correction factors 1.0.
Reach = (13/25 x 10/12 x 1500/500)² x 1.0 => 100% of detail benchmark picture. Warbler is covering 100 % full frame.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Relatively small usually quite active bird. High quality sensor Z50, effective Lightroom editing and direct sunlight create light contrast and colour depth and perfect detail in this almost one-tint brownish picture. A bit of strong wind is finishing touch.
Reach = (22/25 x 10/12 x 400/500)² x 0.8 => 35 % of detail benchmark picture.
CLight x CAtm x CLens x CSensor = 0.8 x 1 x 1 x 1 = 0.8
Particularly the large amount of noise makes that it looks like this picture contains less satisfactory resolved detail. It has also low colour contrast. Nevertheless it is not too bad considering the extraordinary long exposure time 1/15 second. We used a tripod.
Reach = (44/25 x 10/25 x 1050/500)² x 1.0 => 225 % detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Larger bird not far away. Splendid detail, very goo light contrast and colour contrast. Oystercatcher is expert in opening shells. His juveniles learn this profession from the adults.
Reach = (51/25 x 10/35 x 750/500)² x 1.0 => 225 % detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
When photographing large birds the size of a bird becomes important in a completely different way: the question is not any more “Do I have sufficient reach?” but rather “Will this large bird fit within about 3/4 of a full frame image so what equivalent should I use?
In this example we were expecting a Black Woodpecker (Zwarte Specht), man, official size 51cm, distance 30 meter to show up soon. We might get but one brief moment to shoot pictures when the bird would arrive near the nest whith breeding wife. We already could hear man’s sound announcing its arrival to his wife far away and desperately needed to know whether we should use or not use the 1.4 converter at our Z50 (on tripod to be able to aim at the right spot high up the tree) and Nikkor 500mm f/5.6E PF VR TC-14E if we wanted a sufficiently detailed more or less frame filling image of this Woodpecker. our estimate, imagening our benchmark picture Great Spotted Woodpecker size 25cm at 10 meter Nikkor 300mm was something like: Black Woodpecker has about twice the size Great Spotted Woodpecker but will be at about about three times distance and now we are using a 500mm in stead of 300mm tele so the Woodpecker may fill more than full frame, which would be a real shame. So we took the converter out and shot this picture. It became our third standard average large bird 35 meter 750mm equivalent. And we do remember this kind of situation so we know by heart what to do next time.
Reach = (31/25 x 10/35 x 1260/500)² x 1.0 => 75 % detail benchmark picture. (145 % detail of “horizontal size” this case in stead of “vertical size” in this case).
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Reach = (26/25 x 10/38 x 1500/500)² x 1.0 => 75% of detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Great detail, realistic colours and very good colour contrast thanks to large equivalent and high quality sensor. Rather large bird not too far away.
@dik repl qm
Reach = (35/25 x 10/20 x 585/500)² x 1.0 => 85 % of detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Good detail and natural colours even using older D300 but pro quality Nikkor 70-200mm f/2.8 zoom and aspherical TC-20E III. Average large bird not too far away.
Reach = (25/25 x 10/25 x 1050/500)² x 1.0 => 45 % of detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Good detail and natural colours using pro quality Nikkor 500mm and high quality D500 sensor. Average large bird not too far away.
Reach = (35/25 x 10/35 x 1050/500)² x 1.0 => 45 % detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Great detail (imagine bird stretched out horizontally) and natural colours using pro quality Nikkor 500mm and high quality D500 sensor. Average large bird not too far away.
Reach = (62/25 x 10/35 x 1050/500)² x 1.0 => 225 % of detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Rich detail (imagine bird stretched out horizontally) and natural colours using pro quality Nikkor 500mm and high quality D500 sensor. Average large bird not too far away.
Reach = (33/25 x 10/12 x 1050/500)² x 1.0 => 200 % detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Good detail with pro quality Nikkor 500mm and high quality D500 sensor. Average large bird tather close.
Reach = (40/25 x 10/25 x 2000/500)² x 1.0 => 85 % detail benchmark picture. This corresponds to about 1/5 of 3000 x 2000 pixels cand is compatble with 60 % of detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Reach = (52/25 x 10/100 x 1050/500)² – 0% => 15% of detail benchmark picture.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Explanation: relatively large bird, far away, good equivalent and sunlight produce usable detail and colour contrast. In some way astonishing goo reach and this became our Standard picture “Absolute limit reach of average size bird using this equipent”-BORDERLINE CASE. Not a real good picture but still usable for practical proof purposes.
CLight x CAtm x CLens x CSensor = 1 x 1 x 1 x 1 = 1.0
Using Reach-formula and quadratic rules in the field
