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R1 360 mm Smart Zoom Surprise - No need for Image Stabilization

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Richard O'Sullivan

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I was only shooting at 1/60 sec because the mild room lighting required that with F/4.8 at 800 ISO.

I was shocked that the following picture did not have any evidence of “camera shake” since I had the R1 set to use Smart Zoom of 15X which gives 360 mm focal length.

I was sitting in a chair with the camera in my 2 hands and my elbows bent at about 90 degrees.
I was holding it out in mid air, not on my lap. Flash was turned off

I had the camera on Monitor Focus which means that it continually focused until I pushed Shutter Button.
I was about 12 feet away from the Santa which is about 12 inches high.

This setting of 15X is obtained when the 1 Mpixel option is used ( 1296 X 864 = 1119744 pixels).

I used a Physical Lens Focal Length of 71.5 mm (135 equivalent 120 mm because of the “crop factor of 1.67).

Now the age old “Rule of Thumb” says that to minimize shake shoot at 1/(focal length).

I thought that I would have needed about 1/360, but obviously not.

So then I reasoned that I would need 1/120, the focal length multiplied amount due to the crop factor.

However it looks like one has to use about 1/71.5, the actual physical focal length of the zoomed out lens !

What is going on here? Does my interpretation make sense at all?
Try it yourself and let me know your thoughts.
Richard
 
...but heres some info that might help...

I'm pretty sure, but not positive, that the important number is actually the magnification. In which case, the equivalent is what really matters. In this case 360.

Still, in all my years shooting, having a fairly steady hand and paying good attention to my "brace" I've cheated the usual rule consistently by at least a stop.

Keep in mind also that even with the worst conditions, you can accidently get a dead-sharp pic, just by chance.

dave
--
Amazing what we can do with just three crayons, red green and blue!
http://diamondmultimediagroup.com
 
The rule is for the actual focal length, 72mm. However if you want to make 15x enlargements a tripod is the way to go. For a 4 x 6 print no problem. The 360mm eqivalent ismart zoom is a crop of the 72mm field of view. The quality of the R1, 1 meg image is exceptional because of the large sensor size (s/n ratio).
 
..on this one. I'm sure in my head now that its the magnification that matters, and the rule was written for 35mm equivalent...meaning the 360 is the important number.

Heres why.

With magnification you get a narrowing of the field of view...but movement of the camera is a roatation of that field of view. You're moving the same number of degrees when you "shake", because zooming doesn't make you any steadier, but each movement degree is a larger percentage of the narrower field of view, making for a more dramatic blurring effect.

In other words, the more you magnify, the more shake effects you...the 72mm zoom on the R1 magnifies just as much as a 120mm zoom on a 35mm camera...therefore 120 is the important number...until you reduce your field of view even farther by cropping, now the shake is significantly magnified again.

I'm going with 1/360 for the rule.

dave
--
Amazing what we can do with just three crayons, red green and blue!
http://diamondmultimediagroup.com
 
Camera motion must of been generous to you. 15x DZ? 3 seconds? That's luck.
 
qball said: "3 seconds?"

NO, you misread my post, I said 1/60 sec shutter speed.

What shocked me was that it appears the the age old rule does not seem to apply for Digital Zoom and also not for the Crop Factor multiplier.
 
Richard O'Sullivan said:
I was only shooting at 1/60 sec because the mild room lighting
required that with F/4.8 at 800 ISO.

I was shocked that the following picture did not have any evidence
of “camera shake” since I had the R1 set to use Smart Zoom of 15X
which gives 360 mm focal length.
Click to expand...
When experiments in physics are taken place and measured, there is always a certain percentage of results that scientists call - measurement error which is then rejected and excluded from the final conclusions.

Moreover, no reliable conclution can be drawn out from one single event, so If you you would shoot at the similar conditions more than 100 pictures and get 90% of them completely free of "camera shake" then you can be shocked and surprized. Otherwise, lets assume that the case you have discribed, falls into the category of "measurement error" and is probably not more than pure one time luck.

Cheers
Moti
 
Well, in fact this is a fairly soft image all over. It isn't objectionable, by any means, but neither is it tack sharp. I can still (at age 64) hand-hold a relatively long lens (150mm equivalent, for example) at about 1/30th, if I'm propped in a way similar to what you describe, but if you blow it up to any size, you can tell it's soft. Shorter lens length, such as 1/50th, I can hand-hold to about 1/8th with the same result. But a solid base will still be what gives me a truly sharp image.

LesleyON
 
of course you don´t need Image stabilization.
but, instead of taking a yoga position etc, use the flash
(S mode-speed 2000)

This is the original photo (I used the smart zoom 1 M)
you have all the EXIFF data



Jane T

Canon 400D & Tamron 28-300mm XR Di
Sony R1
Canon S2 IS
 
AAK said:
Smart Zoom is done in the camera, not in the lens. It's not like
shooting a "real" 360mm lens. Smart zoom should not have any impact
on camera-shake. Any more than you would have without it.
Click to expand...
Gotta disagree. Digital zoom indeed exacerbates camera shake.

Digital zoom (or cropping in post) has exacty the same impact as optical zoom. Camera shake is a factor of camera movement (in degrees or MOA) relative to the field of view (in degrees or MOA).

Try this everyone:

Picture a flagpole at 100 meters distance. It is 12 inches in diameter (12 MOA for you technical types). You hold your camera up and notice that you are a bit shaky. In fact, if you had a laser pointer attached to your camera and pointed it at that flagpole 100 meters away, you'd notice that it is moving 4 inches in every direction. (The laser pointer is used to illustrate that the amount you are shaking is the same regardless of the camera or the lens on the camera, follow?)

Now let's put a camera in your hands. You've just won the lottery and bought the venerable Full Frame Canon 1Ds MkII (image dimensions of 4992x3328 pixels). You slap the ultra-wide 15mm fisheye lens on it (with its 180 degree angle of view). You take a picture of that flagpole and are surprised to find that it is actually VERY sharp. It is VERY sharp because the flagpole is soooo small in the picture, that it only covers a few pixels in width (in fact about 6 pixels) out of the whole picture. And your camera shake covers even less (about 4 pixels). Camera shake gets LESS noticeable the WIDER you zoom. Let's print, frame, and display this one (beautiful sunset in the background, eh?).

Now we can all agree that Digital Zoom does exactly the same thing as Cropping in post, correct? "Precision Zoom" crops in-camera and then up-rezzes to full camera resolution. "Smart Zoom" crops in-camera but keeps the specified resolution (which we would up-rez later on the computer to keep the ultimate resolution the same). Finally, "Cropping" a full-size image and then up-rezzing on the computer is precisely the same as doing it in-camera (jpeg compression aside).

In fact, putting a smaller sensor in a camera is THE SAME as cropping. Unless you also decrease the focal length to maintain an equivalent field of view (thus lenses on smaller sensor cameras are always referred to as "Equivalents"). The effect of camera shake on an H5 for instance (with its tiny sensor and 72mm lens), is precisely the same as the aforementioned Full Frame camera with a 432mm lens. Precisely the same. The same holds true for the R1 with its smaller sensor and "equivalent" focal length lens, or the D200 or 30D or Alpha, etc etc.

Well, let's start digital zooming (cropping) that original scene with a flagpole in it. 2x digital zoom cuts your angle of view in half, thus the flagpole now covers 12 pixels out of the whole picture (double the amount as before). And your camera shake is indeed more noticeable as well (double the amount - now at 8 pixels).

Let's go to 10x digital zoom (1/10 the angle of view). The flagpole is noticeably larger in the picture. It now covers 60 pixels in width, and camera shake covers a whopping 40 pixels! See where this is going?

On to 100x digital zoom (1/100 the angle of view). The flagpole now covers 1/8 of the entire image (600 pixels). And your camera shake almost makes the flagpole unrecognizable (400 pixels of camera shake!). We'd never be hanging this one on the wall!

And of course there is no debate that optical zoom impacts camera shake in exactly the same way. you double the focal length, you double the image size (and also double the camera shake present in the picture).

Camera shake is a function of camera movement (in inches, or pixels across), relative to the field of view of your image (inches in width, or pixels across). Whether using Optical zoom or Digital zoom, the image is ruined if camera shake makes up a large enough percentage of the image.

So use a tripod, turn the IS on, zoom wider and move closer, use less digital zoom, or shorten the amount of time that a camera will travel when you are shaking (by increasing the shutter speed). Hope this helps some.
R2

--
Good judgment comes from experience.
Experience comes from bad judgment.

http://www.pbase.com/jekyll_and_hyde/galleries
 
...that helps a great deal to picture the effect of shake when my pointer is swinging a larger and larger arc the farther away I'm shooting...but a flag pole is still a flag pole way out there, meaning the effect of shake is more and more dramatic. Really doesn't matter how we accomplish the magnification, its the mag that counts.

I think I'll make some diagrams.

thanks
dave
--
Amazing what we can do with just three crayons, red green and blue!
http://diamondmultimediagroup.com
 
Taking a 1 meg crop (smart zoom) from a 72mm lens is not the same as mounting a 360mm lens on the R1 and using the full 10 mega pixels. You will get away with 1/60 sec with the 72 mm lens but not with the 360mm lens. The 360mm 10 meg image will show more camera movement than the 72mm 1 meg crop.
 
As I said "I was shocked" and found it difficult to believe, so I shot the same way 3 more times.

Experimenally I can say that 1/60 sec shutter speed at 360 mm (15X smart zoom) creates no visible camera shake when hand held!

So those of you in the previous threads saying that 1/71.5 was a safe speed, get the Golden Cookie Award!!!

Richard
 
Taking a 1 meg crop (smart zoom) from a 72mm lens is not the same as mounting a 360mm lens on the R1 and using the full 10 mega pixels. You will get away with 1/60 sec with the 72 mm lens but not with the 360mm lens. The 360mm 10 meg image will show more camera movement than the 72mm 1 meg crop.
 
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