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Posted By: MattLFC Digital and Optical zoom - 1st Sep 2007 3:11pm
Ill do the zoom trick for you now by the way.

smile
Posted By: MattLFC Re: Night Shooting - 1st Sep 2007 3:33pm
First of all, here is the optical zoom, from the wide angle end, half way point and finally at full telephoto legnth.

First one is 28mm, second sould be in the 160's - 170's, and the third one should be around 300mm. In lamens terms, that would 1.0x, 5.35x and 10.7x.

Please dont read too much into the colours etc, the only thing I have set it up for testing here, is the telephoto shooting.

All photographs were taken WITHOUT a monopod/tripod, and without image stabilisation.

Attached picture 0x 28mm.jpg
Attached picture halfway 5x.jpg
Attached picture full zoom 10x 300mm.jpg
Posted By: MattLFC Re: Night Shooting - 1st Sep 2007 3:43pm
Now here we take a look at the difference between digital and optical zoom when cropping, and why its always best to crop for quality, but may be better to use digital zoom for detail.

Digital zoom is to be honest, shite. But at very low levels, it can have its uses and can be handy. Personally, id say 2x digital zoom is acceptable, because its effectively only halving the pixel count. It does add in noise and what it thinks should be there, but its never as good as optical zoom as you will see.

My general advice would be dont use past 2x digital zoom and only use it when you really must, otherwise just forget about it in 99% of situations.

I must add that these have very slighly worse compression then the above photo's to ensure they fit under 130KB (the viewable file limit on wiki).

This time you will need to take a look at the colours a bit more. As you can see, the first one is a bit darker, because the digital zoomed one has a lighter area to focus on and draws in a bit more light. This will become more apparent on the next test.

First of we look at the comparison between the top end of the telephoto with and without 2x digital zoom:


Description: 10.7x effective zoom, optical only.
Attached picture full zoom 10x 300mm.jpg

Description: 21.4x effective zoom, obtained via 10.7x optical zoom, then doubled using 2x digital zoom to 21.4x.
Attached picture Picture2 033.jpg
Posted By: MattLFC Re: Night Shooting - 1st Sep 2007 3:55pm
In this test, we take a look at the difference between an on camera digital crop (aka digital zoom) and a crop done in a low end PC program (PSP8 for this one).

I must add that the optical shot was made slightly darker when I put the shot on the PC, so it would be nearer to the lightness digital shot in reality.

Using a higher end program like CS3 would yeild better results. Again, notice the colour difference, but dont read too much into them, as this can also be corrected in your editing programs.

Here is a crop of the 10.7x optical zoom shot, to get it almost the same as the 21.4x shot:


Description: 21.4x digital + optical zoom.
Attached picture Picture2 033.jpg

Description: 10.7x optical zoom, cropped in Paint Shop Pro 8 to the same shot as the above digital zoom shot.
Attached picture Picture2 032b.jpg
Posted By: MattLFC Re: Night Shooting - 1st Sep 2007 4:05pm
And finally, we must look at the detail of each shot, a cropped optical zoom shot and a cropping digital zoom shot.

You will notice, that the lighting difference aside (this is because of the aforementioned difference in how the shot is taken), the colour reporduction on the optical zoom shot is much better, it is a lot more vivid and vibrant.

Also, you will see the digital zoom shot suffers from a loss of detail, even though the optical zoom shot has been cropped to just 500x375 pixel and the digital zoom shot is 1000x750 pixels (resized to 500x375 for the purposes of this test).

There is admittadly a bit of noise on the optical zoom shot (although its the same on the digital zoom shot if not worse, but disguised by the lighting and leack of detail), but if you noise reduction software, it would more then like make it clean again.

I think overall, you will agree that as good and as handy as digital zoom can be, its not "quite" as good as optical zoom cropping on a PC.

I must again mention that the optical shot was made slightly darker when I put the shot on the PC, so it would be nearer to the lightness digital shot in reality.

I should also re-iterate the fact that an old and less powerful PC program was used to crop the images. A newer and more powerful program like CS3 would yeild slightly better results, more noticeable on the optical zoom crop.

smile


Description: A cropped optical zoom photograph to 500x375 pixels.
Attached picture Picture2 032 - crop natural.jpg

Description: A cropped digital zoom photograph to 1000x750 pixels, then resized to 500x375 pixels.
Attached picture Picture2 033 - crop digital.jpg
Posted By: Mark Re: Night Shooting - 1st Sep 2007 6:37pm
[Linked Image]
From This

To this..
[Linked Image]

WOW - How Photography has come along at an affordable price too.

Night Picture = Quality
[Linked Image]

That's about half a mile away from where you were.
Great pics wink
Posted By: MattLFC Re: Night Shooting - 1st Sep 2007 7:22pm
Yep its amazing what results can be had nowadays for less then half the price of of a cheap end DSLR.

This is why I am getting more and more convined that unless you want to a be a pro or maybe semi-pro, there is no need for most people to look at buying a DSLR.

There are still a few advantages with DSLR's, but when you consider the price these advantages demand, then it really outweighs the benefits for most people.

One day I will get around to buying my .45x, 2.2x and 3.2x Opteka lens extension kits, but as yet I think they would be more of a luxury then a nessecity as I havent really found a need for them.

smile
Posted By: Waddi Re: Night Shooting - 2nd Sep 2007 11:06am
Thats a great zoom Matty, thanks for that.

just imagine what it would be like with additional add-on lens such as the 3 you have mentioned above.

I would deffo want the 3.2x lens extension just for gadgets sake.

thanks again for doing that for me

Waddi
Posted By: Wheels Re: Night Shooting - 2nd Sep 2007 11:11am
wow i cant even see it in the first picture. that zoom is amazing.
Posted By: MattLFC Re: Digital and Optical zoom - 2nd Sep 2007 10:02pm
Yeah it would be great to have the 3.2x extension Waddi.

Dont forget though, that image quality may suffer slighly with the extension, because its another lens (theres already 7 on the S6500), and the more lenses you add, the more it impacts on quality.

But, providing the lenses are of high quality, and not really cheap nasty ones, then the difference is usually un-noticeable to everything but a really trained eye lol.

Thats why I am sticking to buy Opteka lenses; they are not as cheap as lot on eBay, but they are reputable lenses from an established company, and are exceptional quality for the price rnage they are in.

They are also around 1/3 the price of the Fuji lenses, and I very much doubt the Fuji lenses are 3x better lol.

Yeah the zoom is quite good Whelan fella, ive been made up with it. Its only 10.7x, but this thread shows how powerful and effect a mid-range zoom can be.

smile
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