Don't be afraid of digital zoom!

[NicksGarage]

I know a lot of people say to stay away from digital zoom but I find it useful in certain situations. I have the S2 and I have it turned on. I don't know about other cameras but it's hard to accidentally zoom into that range when it's turned on. On the S2 you can zoom all the way out to 12x very quickly but if you want to get into the digital zoom range you have to release the zoom lever and then zoom again. It's very clearly marked on the scale as well.

The other night I was trying to take some pictures of the moon and using the full 12x zoom, the moon was just a bright spot in the middle of the image. There were very light clouds in the sky and they showed up on the image as well.

Using the 48x zoom, I could see the details on the surface and also adjust the exposure and white balance to get the shot right. Of course these are nowhere near as sharp as some I've seen from an SLR with a big expensive lens but I was pretty happy with the results given the shooting environment here in the city. I'm looking forward to trying it from the mountains or the desert.

This has only been cropped, no processing. Looks better resized smaller.



There are five shots in this folder: http://nicksgarage.com/photos/canon/062405moon

I've used the digital zoom in a couple other situations as well. Better to have it available all the time than to have to go to the menu to turn it on when needed.

Nick.

 

[Ron Parr]

You can always shoot at full optical zoom and just crop later.

--
Ron Parr
Digital Photography FAQ: http://www.cs.duke.edu/~parr/photography/faq.html
Gallery: http://www.pbase.com/parr/

 

[mamallama]

However when you digital zoom in closer you get the benefit of setting the exposure and WB more on the moon with less influence of the dark surroundings. A built-in narrow spot meter that used to cost a mint in the old days.

--mamallama

You can always shoot at full optical zoom and just crop later.

--
Ron Parr
Digital Photography FAQ:
http://www.cs.duke.edu/~parr/photography/faq.html
Gallery: http://www.pbase.com/parr/

 

[Ron Parr]

However when you digital zoom in closer you get the benefit of
setting the exposure and WB more on the moon with less influence of
the dark surroundings. A built-in narrow spot meter that used to
cost a mint in the old days.

The S2 already has spot metering though.

--
Ron Parr
Digital Photography FAQ: http://www.cs.duke.edu/~parr/photography/faq.html
Gallery: http://www.pbase.com/parr/

 

[mamallama]

The S2 already has spot metering though.

--
Ron Parr

That I know and the camera definitely should be in spot metering mode. The benefit of digital zoom arises when the metering spot extends beyond the subject of interest, moon in this case. The original poster stated "the moon and using the full 12x zoom, the moon was just a bright spot in the middle of the image". He also implied that with digital zoom he was able to achieve better exposure and WB.

This digital zoom technique has been discussed before on the Panasonic forum where long zooms have been common for some time. Using this technique there have been postings of some extremely well exposed faces of performers in the spotlight of a dark concert hall taken from a distance.

In essence, you are turning a narrow spot meter into an extremely narrow spot meter.

--mamallama

 

[Ron Parr]

Do you really think that the metering spot extends beyond the subject in this case?

Of course, there could be cases where it does...

--
Ron Parr
Digital Photography FAQ: http://www.cs.duke.edu/~parr/photography/faq.html
Gallery: http://www.pbase.com/parr/

 

[NicksGarage]

I could not have gotten the same image by cropping a 12x zoom image.

In other situations you can certainly do it. I'm going to do some tests with regular earth based subjects to see the difference if there is any due to cropping before saving as a jpg.

My whole point was that you can do some things with digital zoom that you can't without it. And since the S2 is set up to make it hard to accidentally get into that zoom range, why tell everybody to turn it off. If someone ends up needing to cropping 100 images they could save time by using the digital zoom.

Nick.

 

[Ron Parr]

I could not have gotten the same image by cropping a 12x zoom image.

This is certainly false.

My whole point was that you can do some things with digital zoom
that you can't without it.

Like what?

--
Ron Parr
Digital Photography FAQ: http://www.cs.duke.edu/~parr/photography/faq.html
Gallery: http://www.pbase.com/parr/

 

[denomolos]

There's another advantage to using digital zoom instead of cropping/resizing afterwards. The cropping/resizing done in-camera is done with the raw image date, before any JPEG compression is applied. I haven't done any testing to see if there is actually a noticeable difference, but someone here once said that there was, and theoretically there should be a difference.

 

[mamallama]

Ron:

Only Nick knows. Not me, not you. He says yes.

I've seen no spec on the angle of the S2 spot at the 12X zoom, nor do I, nor do you know the angle of the moon subtended from where location where Nick was taking the picture. I just KNOW that it is a technique that works when the situation exists and that's all I was pointing out. No need to get augmentative about it.

--mamallama

Do you really think that the metering spot extends beyond the
subject in this case?

Of course, there could be cases where it does...

--
Ron Parr
Digital Photography FAQ:
http://www.cs.duke.edu/~parr/photography/faq.html
Gallery: http://www.pbase.com/parr/

 

[Steve in the Big Oh]

Hi Nick,

I've noticed the same nice division between optical and digital zoom on my old G3, and leave digizoom turned on, even if just to get a better look before I snap the pic using only optical zoom. I've noticed that the division is not there when going back toward wide angle, though, so I need to watch for the WHITE 4.0X on the LCD.
--Steve.
--
Go a little farther, see a littler farther.

 

[wazza]

There's another advantage to using digital zoom instead of
cropping/resizing afterwards. The cropping/resizing done in-camera
is done with the raw image date, before any JPEG compression is
applied. I haven't done any testing to see if there is actually a
noticeable difference, but someone here once said that there was,
and theoretically there should be a difference.

I speak from limited experience with the Optio 750Z. Given it is 7mp it allows a lot of cropping.

It also has a two stage digital zoom - 2x and then another option up to 8x which are selected separately

I do notice better images using the onbaord 2x digi zoom than cropping afterwards.

There are fewer jaggies and seems to be sharper colour definition. It is really noticeable - not really but as I don't like post processing if I donb't have to, onboard cropping is fine by me.

Now, I'm not sure if the same is true with the S2

Mind you, the 750Z has a dedicated exposure meter separate from the image capture function as well which is quite useful.

 

[Bob Schrader]

angle of the moon

the full Moon is a half a degree wide as seen from the Earth

 

[relate22]

I just did a comparison on the photos I took in this thread.
http://forums.dpreview.com/forums/read.asp?forum=1010&message=14060470

The optical photo cropped has more jaggies and halos than the digital zoom photo. I don't understand the physics of it but for me I will be using the digital zoom more than I would have otherwise, it quiet suprised me at the quality of the digital zoom.
--
http://www.pbase.com/reelate2
http://www.pbase.com/relate2

 

[NicksGarage]

I just did a comparison on the photos I took in this thread.
http://forums.dpreview.com/forums/read.asp?forum=1010&message=14060470

The optical photo cropped has more jaggies and halos than the
digital zoom photo. I don't understand the physics of it but for me
I will be using the digital zoom more than I would have otherwise,
it quiet suprised me at the quality of the digital zoom.
--

Thanks for the examples. I don't know why people are so turned off by the digital zoom yet they never seem to provide images to support their claims.

I tried to take my moon shot at 12x so I could compare the differences but I couldn't get one where the moon wasn't totally blown out. Maybe an expert photographer could with the right settings.

So if the tool works, why not use it?

Nick.

 

[imbsysop]

There's another advantage to using digital zoom instead of
cropping/resizing afterwards. The cropping/resizing done in-camera
is done with the raw image date, before any JPEG compression is
applied. ..

plse point us to some articles that discuss this on an argumented/technical level ? as to me this is mythical nonsense .. the "raw" data have no "pixels" so how would you zoom them digitally ?

--
if needed, email me at : [email protected]
Horum Omnium Fortissimi Sunt Belgae !
HP912C, G6, S2 IS soon?

 

[imbsysop]

sorry for not sharing the general euphoria .. but seen at 100% that's a hell of a blurred picture .. aka typical extrapolated pixels .. check other moonshots on this forum for comparison ..
FWIW

--
if needed, email me at : [email protected]
Horum Omnium Fortissimi Sunt Belgae !
HP912C, G6, S2 IS soon?

 

[Ron Parr]

Ron:

Only Nick knows. Not me, not you. He says yes.

He hasn't even said if he was using the spot meter.

If you really had to, you could use the digital zoom to meter, but still use a regular capture to get the image.

I've seen no spec on the angle of the S2 spot at the 12X zoom, nor
do I, nor do you know the angle of the moon subtended from where
location where Nick was taking the picture. I just KNOW that it is
a technique that works when the situation exists and that's all I
was pointing out. No need to get augmentative about it.

I agree with you that there can exist metering modes and situations where it's to your advantage to reduce the area the camera is monitoring in some way.

However, you won't get something for nothing. With a 4X of digital zoom, you're taking a 640x480 crop from the center of the image and interpolating it up to 5MP.

The only advantage to doing it in camera is that you might squeeze more past the quantization threshold of the jpeg algorithm, so any perceived benefit is an artifact of shooting with a camera that doesn't support RAW.

The disadvantage is that for magnifications that are not integer valued, your camera will use a worse interpolation algorithm than what a good piece of software would do on your PC.

--
Ron Parr
Digital Photography FAQ: http://www.cs.duke.edu/~parr/photography/faq.html
Gallery: http://www.pbase.com/parr/

 

[pleith]

Oh really! The raw data is not made up of pixels? Smarties perhaps.

phil

 

[wazza]

Oh really! The raw data is not made up of pixels? Smarties perhaps.

phil

When you open the RAW data in your editing software the header is read and used to display an image of the RAW data.

Note I said display -- the actual RAW data is never affected.