Some Crazy Zoom

[Andrea B.]

This has nothing to do with UV/IR. But I thought you all would enjoy it anyway.

 

Yesterday I was playing with the Nikon P900 rented from LensRentals.com for 5 days. What fun!! This is a 16MP Coolpix zoomer -- very lightweight, articulating LCD, built-in GPS, Wi-Fi uploads, image stabilization and massive zoom out to an equivalent 2000mm.

 

What's not to like about all those goodies as long as you are not expecting DSLR image quality? That is not to say that this zoomer can't produce a nice enough foto at the normal ranges from 24mm - 200mm or even more. But if you have ever shot any telephoto of substantial length, you already know that the atmosphere can get in the way. Heat waves, air waves, pollution waves or whatever waves might be present produce that wonderfully wavy quality at long extension which obscures details and gives an underwater appearance to distant subjects.

 

Here is a series in two posts made from the widest zoom setting at 24mm up to the completely crazy 2000mm. I screwed up the exposure midrange from 50mm-300mm. Sorry 'bout that! Not the cam's fault. Around 400mm the atmosphere begins to intrude for distant subjects. Closer objects hold up pretty well.

 

These shots were made from Sandy Hook National Recreation Area in New Jersey looking across the Bay to the Freedom Tower in the lower Manhattan area of New York City. There are probably a few buildings from the west edge of Brooklyn (Bay Ridge, Sunset Park, Red Hook) in between. This is a distance of approximately 16 miles, or 24 kilometers.

From one of the GPS recordings.

Lat [N40°28'18.4"]

Lon [W74°00'21.3"]

Alt [4.50]

 

I was testing the P900's image stabilization capability (good!) and was not on tripod.

 

The actual focal length is first followed by the equivalent focal length. I used the lens memory stops to shoot the series. When that is turned off, any zoom length between 24-2000mm (4.3-357mm) can be used.

 

4.3/24mm

5/28mm

6.2/35mm

8.9/50mm

15.2/85mm

18.7/105mm

24.1/135mm

35.7/200mm

53.5/300mm

71.4/400mm

 

 

Series continued in next post.

[Andrea B.]

Series continued from preceding post.

It is obvious now, for sure, that I was not on tripod. At these long extensions even the most minor movement produces very large changes in the position of the distant subject. Starting around 178/1000mm I can no longer keep the Freedom Tower centered in either the viewfinder or the LCD.

 

89.2/500mm

107/600mm

143/800mm

178/1000mm

214/1200mm

250/1400mm

285/1600mm

321/1800mm

357/2000mm

[Andrea B.]

Here are some examples showing that the zoom can provide enough details for identification of distant birds. Of course, the closer you are to the subject, the better the image quality you will get with such massive zoom.

 

 

Yellow Warbler, Male @ 380mm, approx. (67.8mm)

Resized down to 800px max.

Crop not resized.

 

 

Green Heron @ 2000mm (357mm). A bit of either blur or atmospheric interference?

Resized down to 800px max.

Cropped, resized 50% down. Click up to 1100px height.

 

 

Red-wing Blackbird, Male @ 2000mm (357mm).

Resized down to 800px max.

Crops not resized.

 

 

The camera wanted to grab the background for focus here. But that was a tiny dark swallow, so I wasn't surprised. There are a variety of AF settings to help place focus point.

Resized down to 800px max.

80.3/450mm, approx.

It is absolutely impossible to aim a 2000mm extension at a tiny subject, so I had to "step" my way to that maximum extension. You have to be lucky enough to get a calm, sitting bird to set up a shot with this kind of zoom.

Crops not resized. Click up to 1100px height.

321/1800mm, approx.

 

 

A moon shot made later. The P900 has one of those Scene settings entitled Moon !! It seemed to work. Here the atmosphere between earth and sky was much clearer.

Cropped, resized 50% down. Click up to 1170 px height.

321/1800mm, approx.

 

 

These crabs crawl out of their den, wave their big arm around while doing deep knee bends, and then scurry back into the sand. It's probably a territorial thing.

Cropped, resized down to 300px max.

Either 143/800mm or 170/950mm, approx.

 

 

Cropped, resized down to 400px max.

170/950mm, approx.

250/1400mm, approx.

143/800mm, approx.

[Andrea B.]

A boring subject, but this short series serves to show that when there are not so many atmospheric waves between you and the subject, things are less wavy and image quality is better.

 

All resized down to 800px max.

 

4.3/24mm

 

71.4/400mm (midway??)

 

357/2000mm

[msubees]

Nice test, Andrea. I have a P500 also. When I tested, i thought the image quality was ok, later I found out that at the 100% crop, it was similar to your bird pictures here...horrible! later I did not use it as much. I found that my old coolpix 3.2 meg did not have this problem -- its 100% crop was similar to my D70 at the pixel level. I thought these high pixel counts on a tiny sensor was a marketing gimmick... you will never get good quality at pixel level once it is more than 8 megpapix, or perhaps 5. so 12 or 20 makes no difference...

[Andrea B.]

Agreed. The P900 is definitely a "snapshot" camera, and I don't want to look at anything from it at 100% size. :)

 

It is a lot of fun though. And does get enough detail of a distant bird to enable identification as long as the bird sits still for a minute. :(

 

OTOH, I could probably do a fairly good job of ID-ing birds with my Nikon D810 + 70-200/4. And with that I wouldn't have to worry about convincing them to sit still because that lens focuses so fast.

[msubees]

The last photo is quite impressive, for its clarity. I am still at a loss when my P500 will produce good photos and when not. it seems wide angle upclose is ok, but long zoom is not...

[nfoto]

These photos are more "pictorial" than "horrible" - also a nice demonstration that a long lens whether you calculate a faked focal length or not, is difficult to use efficiently unless you are quite close to the subject.

[Andrea B.]

....and of course if you are quite close to the subject then do you really need a long lens?? :D

 

I'm not sure what you mean by a "faked focal length"??

Whatever the focal length really is at full extension, the P900 did manage to magnify the Freedom Tower which was 16 miles away into a visible object (give or take a few heat waves) so large that it would no longer fit into the frame. I did not have "digital zoom" turned on.

[nfoto]

The focal length is *NOT* 2000 mm ... that is a faked number. Same with 24 mm as the shortest focal lenghth (it is actually 4.3 mm). People confuse focal length and angle of view. The internet is awash with such statements. Don't add more of them.

 

It is unclear from the specification whether the max focal length of 357 mm represents some equivalent obtained by 'digital zoom'. Seeing the lowered quality I'm inclined to believe such enlargement is in effect in-camera.

 

As to your question about using long lenses in the near range, any bird photographer will tell you that you simply cannot get the lens long enough. Birds are surprisingly small subjects even seen through a 500 mm lens.

[Andrea B.]

I started out as a bird photographer and wound up as a uv photographer. Go figure.

 

Those are Nikon's fake numbers, not mine. I don't want people thinking that what you said implies *I* faked something. The focal lengths of this P900 given in the camera menu as 24/28/35/50/85/105/135 and 200/300/400/500/600/800 and 1000/1200/1400/1600/1800/2000.

[nfoto]

Never implied that. However, Nikon has a marketing department and they are the guys who write the ads and manuals etc. They love to play "a number game". Simple as that. Everything being equal, bigger number sells. Human nature. That is why the crazy megapixel race continues even for these tiny sensors.

 

Do a little calculation about the size of the lens were it to be truly f/6.5 @ 2000 mm. Then factor in the weight of the required glass.

 

The actual focal length has a bearing on the depth of field you get.

[Andrea B.]

When you dial in "fake 200mm" on the P900 and "real 200mm" on the D810 + 70-200/4G, you get pretty much the same photo regardless of what the actual underlying focal length is. So is some sense it is a useful labeling. I think people are in it for that (the zoom) and don't really care so much about the DoF. So they probably don't care whether the numbers are "faked".

 

Both: f/6.3 @ ISO-400 for 1/40"

One foto is "fake 200mm". The other is "real 200mm".

So, which is which ?? :D :P

(I do see that there is some rounding error.)

 

 

[nfoto]

Again, you are talking about angle of view using the focal length terminology. It simply is not the case and one gets all sorts of wrong conclusions by confusing the two. Depth of field is the first victim and lots more to follow.

 

So what is wrong about thinking a lens has actual focal length of 4.3 mm instead of the faked "24 mm"?? One immediately understands it has very small magnification thus inherent great depth of field, plus if the lens is stopped down too much, diffraction will rob the image of clarity. One also is aware of the need to move in very close to a subject in order to render it clearly. Thus even a distance of a few cm will NOT produce a real "macro" image. Were the actual focal length 24 mm one couldn't focus the lens up close in the same manner. Thus, for the ideal case of a "thin" lens, one couldn't focus it closer than 10 cm. All this follows directly when one uses the real not faked focal length. I fail to see why illusions are to be preferred over hard facts.

[Andrea B.]

*I'm* not talking about that. Stop saying "you", please !!

[nfoto]

I'm not referring to you per se, it is a general statement. Perhaps English lacks the distinction present in other languages? I have amended the earlier post to make this clearer.

 

In the example for "200 mm", look at the depth of field to see the difference. If the aperture settings (and focus) were identical, one cannot have a huge variation in depth of field for two identical focal lengths. QED.

[Andrea B.]

And so "real 200mm" and "fake 200mm" at a fixed distance from the subject produce two photos

which are basically identical except for depth of field.

What wrong conclusions do people draw from this I wonder?

 

What we should say: :D :P

35.7mm over a 6.17x4.55mm sensor and 200mm over a 36x24mm sensor at a fixed distance from the subject produce two photos

which are basically identical except for depth of field.

[nfoto]

They have (approx.) the same field of view. Most other image parameters (manifested resolution, noise, depth of field etc.) are not identical.

[Andrea B.]

Thing is - the watercolour effect is so horrible that I am not even tempted by this P900 at all. It goes back to LensRentals.com tomorrow.

 

I do like this watercoloured, unresized extract of a moon crater though.

[Andrea B.]

I fail to see why illusions are to be preferred over hard facts.

 

You are preaching to the choir.

Perhaps this should be taken up with the great unwashed masses who love their illusions. :D :P

 

(Sometimes I enjoy a few illusions myself. But I am digressing......it is time to eat some ice cream.)

[nfoto]

Alas, I'm out of ice cream. And lack even the slightest touch of a faith to preach. A British crime rerun on the TV has to do.