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TwoBytes

macrumors 68040
Original poster
Jun 2, 2008
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Is it that much of a difference?
Any photographers care to comment on the aperture bump? Any example
pics to illustrate the difference?
 
2.4 is faster. Drinks more light.
Better sharpness, creamier bokeh for portraits.
better in lower light situations.
etc
 
A bigger aperture lets in more light to the sensor. The real explanation gets a bit more complicated since it's really a ratio, not an indication of an absolute amount but for now, just think it as a larger window that let's in more light and "blurs" the background a bit better when needed.

This can help in two ways: 1) you can use a lower ISO value, which will improve the picture quality or 2) you can use a faster shutter speed to freeze the action with less blur and I almost forgot, the separation of the background by having a shallower depth of field - more blurred background.

The faster aperture in itself is nice but not a massive improvement since it's not even a full stop (twice the light amount) gain. However since the quality of the lens optics have been enhanced along with a much faster operation as well as a better image processing, the camera will likely be much much better in the iPhone 4S.
 
F/2.4 is roughly / close to 1/2 of a stop faster. You will get faster shutter speeds which will reduce motion blur and stop action better. Plus 1/2 stop will do better at night and the phones flash will carry further as well. Not as much falloff. I think the new video stabilization will be awesome for less shakey videos.
 
The difference is NOT ground breaking but will make a difference. I also understand the sensor is greatly improved in other than just increased pixels.

Sounds like the camera will really be useful.
 
That's an amazing photo with some great depth of field. Is that the 4s?

RE depth of field, what's the next barrier towards getting SLR depth? (focused foreground/background with the blur visa versa)
 
So is f/2.4 better than f/2.8? And f/2.2 would then be even better? I don't know much about photography but I'm curious to see what difference it makes
 
So is f/2.4 better than f/2.8? And f/2.2 would then be even better? I don't know much about photography but I'm curious to see what difference it makes

Absolutely but as with everything a bigger aperture usually increases cost and size so there's a limit.

Also it's hard to directly compare aperture to another camera when the sensor size is different. For instance, the Nokia N8 has a f/2.8 lens but its sensor is larger than other camera phones so the total amount of light collected is more than other f/2.8 camera phones. Ditto for DSLR f/2.8 lenses against f/2.8 equivalents from smaller cameras. (This is actually flame bait material in many parts of the internet. ;) )
 
That's an amazing photo with some great depth of field. Is that the 4s?

RE depth of field, what's the next barrier towards getting SLR depth? (focused foreground/background with the blur visa versa)

Yes that's the 4S. The next barrier is focal length. Depth of field is proportional to aperture (the lower f/ the better) and the focal length (the longer the better). However with the thinness of smartphones you can't get very long focal length and also longer focal length means a narrower angle so it's better to just have bigger aperture.
 
Absolutely but as with everything a bigger aperture usually increases cost and size so there's a limit.

Also it's hard to directly compare aperture to another camera when the sensor size is different. For instance, the Nokia N8 has a f/2.8 lens but its sensor is larger than other camera phones so the total amount of light collected is more than other f/2.8 camera phones. Ditto for DSLR f/2.8 lenses against f/2.8 equivalents from smaller cameras. (This is actually flame bait material in many parts of the internet. ;) )

Thanks. I understand that it's probably not the sole factor in picture quality. I asked because I've been looking at the HTC Titan with has f/2.2, but from shots I've seen so far the 4S still has better results. Cameras aren't really a big deal to me, I barely take pictures, but I'm always interested in learning about new stuff.
 
I have just took two sample pictures showing the differences. They are only slight.

I used a Nikon D80, with the Nikkor 50mm prime lens, ISO 100, 1/60th Shutter speed. I couldn't select F2.4, so had to choose F2.5 and F2.8 instead, so it's not quite as big as the difference between F2.4 and F2.8, but you get the idea. You should be able to tell the F2.5 is slightly brighter. And no, the IP4S will definitely not take pictures that look this clean in low light, not even close ;)

Shot at F2.8
f28.jpg



Shot at F2.5
f25.jpg
 
2.0 is where the magic starts to happen though.

Yeah. F1.8 shot incoming just for comparisons sake..

Here we go. This clearly shows the advantages of using low fstop.. this is F1.8, way bigger aperture than Ip4s can achieve. Look how much brighter it is.

DSC_1450.jpg
 
Some folks in here need to read a little photography 101 before making the blanket statement that it's a huge improvement. Yes, low light photos will be slightly better but it makes absolutely no difference in bright light.

Optics will have a far more significant effect on image quality than the fact that you gain about a 1/2 stop. Also keep in mind that as aperture increases, Depth of Field decreases and vice versa. That means the bigger the aperture you are shooting at, the less that will be in focus in your photo.

Now, that's fine if you are trying to a achieve an effect with a blurred background such as in my photo below where I wanted to draw focus to the front most parts of the scene. (f/3.5 here)


Niagara Falls Botanical Gardens by zerind, on Flickr

BUT, if you want the entire scene in focus you want to use a higher f/stop (f/11 here)


Place of Refuge - Big Island, Hawaii by zerind, on Flickr

It's a lot more complicated than just what I said but since the iPhone lacks manual control much of this is a moot point since the device will do whatever it thinks is best to get a proper exposure, but if you want to learn about aperture here is a good article - http://www.digital-photography-school.com/aperture
 
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Some folks in here need to read a little photography 101 before making the blanket statement that it's a huge improvement. Yes, low light photos will be slightly better but it makes absolutely no difference in bright light.

Optics will have a far more significant effect on image quality than the fact that you gain about a 1/2 stop. Also keep in mind that as aperture increases, Depth of Field decreases and vice versa. That means the bigger the aperture you are shooting at, the less that will be in focus in your photo.

Now, that's fine if you are trying to a achieve an effect with a blurred background such as in my photo below where I wanted to draw focus to the front most parts of the scene. (f/3.5 here)



BUT, if you want the entire scene in focus you want to use a higher f/stop (f/11 here)



Since the iPhone lacks manual control much of this is a moot point since the device will do whatever it thinks is best to get a proper exposure, but if you want to learn about aperture here is a good article - http://www.digital-photography-school.com/aperture

Yeah.

We just need manual controls now. Chances of apple doing that are tiny..

Generally, the phone will get it right. Most people are going to be using it to take snaps during the day anyway, so it should use a high f-stop and get most stuff in focus.
 
Some folks in here need to read a little photography 101 before making the blanket statement that it's a huge improvement. Yes, low light photos will be slightly better but it makes absolutely no difference in bright light.

Optics will have a far more significant effect on image quality than the fact that you gain about a 1/2 stop. Also keep in mind that as aperture increases, Depth of Field decreases and vice versa. That means the bigger the aperture you are shooting at, the less that will be in focus in your photo.

Now, that's fine if you are trying to a achieve an effect with a blurred background such as in my photo below where I wanted to draw focus to the front most parts of the scene. (f/3.5 here)

[url=http://farm7.static.flickr.com/6064/6158932394_ae0d71d41d_z.jpg]Image[/url]
Niagara Falls Botanical Gardens by zerind, on Flickr

BUT, if you want the entire scene in focus you want to use a higher f/stop (f/11 here)

[url=http://farm4.static.flickr.com/3072/5707746168_6faea05961_z.jpg]Image[/url]
Place of Refuge - Big Island, Hawaii by zerind, on Flickr

It's a lot more complicated than just what I said but since the iPhone lacks manual control much of this is a moot point since the device will do whatever it thinks is best to get a proper exposure, but if you want to learn about aperture here is a good article - http://www.digital-photography-school.com/aperture

When I said higher aperture meant better depth of field, I was considering the guy was asking what makes your background more blurry, cause that's probably what he wants. It has to do with the style of the picture, not the quality. If what you want is a sharp picture, yes, good optics is what you're looking for. I never said a bigger aperture meant more depth of field, not sure who your photography 101 thing was targeted at.

And yes, aperture matters even in bright light. Your shutter speed will be much faster, meaning less blurry shots even in movement, and if the iPhone has auto ISO (not sure), it will be lower meaning less noise. Not that there's usually a lot of noise in bright pictures, but a lower sensivity never hurts.

Outside on a bright sunny day at f/1.8, if I don't lower my ISO too much I can almost run while taking shots and my pics won't be blurry.
 
When I said higher aperture meant better depth of field, I was considering the guy was asking what makes your background more blurry, cause that's probably what he wants. It has to do with the style of the picture, not the quality. If what you want is a sharp picture, yes, good optics is what you're looking for. I never said a bigger aperture meant more depth of field, not sure who your photography 101 thing was targeted at.

And yes, aperture matters even in bright light. Your shutter speed will be much faster, meaning less blurry shots even in movement, and if the iPhone has auto ISO (not sure), it will be lower meaning less noise. Not that there's usually a lot of noise in bright pictures, but a lower sensivity never hurts.

Outside on a bright sunny day at f/1.8, if I don't lower my ISO too much I can almost run while taking shots and my pics won't be blurry.

With any half decent DSLR you should be able to get atleast 1/1000th sec or faster at f1.8 with a decent iso level on a sunny day. So yeah, running shouldn't be a problem. Not that you'd want to run with a camera :p
 
Photography 101 comment wasn't aimed at you, but of course there are always situations where settings matter which is why a fully manual setting is nice. But, you shouldn't be getting camera shake at any reasonable shutter speed in daylight conditions anyway ;)

And yes, aperture matters even in bright light. Your shutter speed will be much faster, meaning less blurry shots even in movement, and if the iPhone has auto ISO (not sure), it will be lower meaning less noise. Not that there's usually a lot of noise in bright pictures, but a lower sensivity never hurts.
 
I've learned a lot from this thread.

Although it reads like a bigger number f stop would mean better depth of field for some scenarios for sharpness

Example http://www.cambridgeincolour.com/tutorials/depth-of-field.htm

The first pic in the left looks better than the one of the right. As the iPhone has a smaller number appeture, you couldn't get the shot on the left. I have to remember though, it's only a phone...
 
Some things to know about photography.

Cameras, analog or digital work by recording light that falls on an image plane. There are generally 4 ways to manipulate how much light reaches this image plane. All of them have benefits and shortcomings which not only determine how much light reaches the image plane, but how the camera "sees" the shot.

A properly exposed image will require "X" amount of light (value variable by image sensor sensitivity and ASA speed rating of film, or ASA simulation of sensor)

You can directly control the light falling on the image plane by

1 - Actual increasing or decreasing the amount of light in the scene. I.E. use strobes (flash), continuous light, open a window, use reflectors, etc. All these methods actually increase (or decrease) the amount of light on your subject. This is often the most difficult option and often is not even possible. Creatively it may alter the tonality of the scene, add or remove shadows, color the scene differently, etc.

2 - Increase the sensitivity of the recording medium. In film this means actually using a more sensitive film (dsignated by ISO rating) or by treating the film as a sensitivity other than native and correcting for this adjustment in processing. In digital it means setting the camera to a higher or lower ISO sensitivity (simulated and adjusted by adding analog gain to the output of the sensor. All sensors have a native sensitivity and others are adjusted). Higher ISO speeds allow the image plane to be more sensitive (require less light to be recorded for proper exposure) at the cost of increased image coarseness or "grain". High ISO films are used artistically to increase grain and give a more coarse, rough and less continuous tone image. Digital can be used this way but digital noise if less flattering and holds a lower aesthetic than film grain and thus high ISOs are used out of necessity rather than artistic intent. Photoshop is much better at adding artistic grain patterns.

3 - Increasing or decreasing the shutter speed. The longer the shutter is held open the more light is recorded per exposure, at the cost of clarity. That is, a fast shutter usually produces the sharpest image because it is immune to smearing from subject or camera movement. The longer the shutter speed the more you will be prone to motion blur. Examples of creative use of this would be selecting a very fast shutter speed to freeze the action in a sporting event. Individual sweat spots are frozen sharply, as well as action that can rarely be seen as such in real life. Examples of when youd want to use a slow shutter speed might be in photographing a waterfall. Instead of rendering discrete droplets or water the photo can be made to show a smooth stream, almost in motion. A very long shutter speed can even be used to photograph a busy roadway and make it appear as though there isn't even traffic on it. Most people select shutter speed out of necessity, rarely realizing what a powerful creative device it is. Search "panning shots" and see what a slower shutter speed can do to high speed racing shots for example.

4 - By increasing or decreasing the speed of the lens. This is the f-stop or aperture setting that is the topic of discussion here. Obviously a larger optic system can gather more light than a smaller one (diameter) when focusing on a same size image plane. The tradeoff is depth of field. When using very fast lenses and very wide apertures the depth of field is reduced. that is to say the focal plane of the image is narrower. This is how portrait photographers like myself keep the subject sharp and make the background go smoothly out of focus. It isolates the subject without taking it out of the scene. You have to be careful though, you can easily focus on the tip of your subjects nose and have the eyes go out of focus. A good reason why you don't always just reach for a wide aperture without knowing your stuff. this background blur is increased significantly at longer focal lengths. It is also relegated to larger sensors. It is difficult to get nice BG blur on small sensor cameras. Tip, use max aperture and max zoom. Put as much distance between your subject and the BG as you can. Smaller apertures increase the depth of field and thus allow several planes to be captured in sharp focus. Landscape photographers rarely use wide apertures unless they are limited by the 3 criteria above. Sharpness is paramount throughout the depth of the photograph. Keep in mind most lenses have a sweet spot as well. e.g. corner sharpness is poor wide open or at ver high apertures like f16, but edge to edge sharpness is highest at f6.3. This is different for every optic system and requires observation to learn.

So there you have it. If you want a snapshot let your camera manage the scene for you. It will usually perform admirably. If you want to make your image yourself become familiar with the tools listed above. you can increase shutter speed to freeze your subject, but you will have to get that lost light from somewhere else be it a faster lens, higher iso, or adding light to the scene. Of course, those methods may introduce new drawbacks. You can choose a smaller aperture to make your image sharp from foreground to deep into the background, but you need to make up that light. Choose a slower shutter speed, but beware camera shake or image movement. Use a tripod. You can use a flash, but beware uneven lighting, hot foreground, or unwanted shadows.

So you see, photography really is an art. A faster aperture is just another tool you can reach for. Higher ISOs are probably the most coveted feature after a good sharp, fast lens. If you can shoot at higher sensitivities without objectionable grain it greatly increases your flexibility. Small sensors like those in phones and point and shoots are getting really good, but are not anywhere near large sensor cameras in this regard. Clean ISO 1600 is a reasonable expectation in an SLR theses days, and usable ISOs up to 3200 and 6400 are to be found. Small cameras are lucky to get ISO400 cleanly, and I'm afraid phones can't expect even that. Be prepared to introduce more light into your scene for a good image. For this reason, f2.4 is a pretty useful upgrade from f2.8, sharpness and image processing aside. It gives you more usable light to make pictures with!

For those of you that bothered to read this, you just got a whole lot of information to play with. I hope it helps make your photography more enjoyable and helps you get better results!
 
Everybody will agree that 2.4 is better than 2.8 if everything else is equal. But it is not. Unfortunately iPhone 4S lens has longer focal length. It's an equivalent of 35mm (in classic 35mm camera terms) vs 28mm for iPhone 4. iPhone 4 has wider lens which gives it an advantage when shooting in tight spaces (or big objects).
For comparison, Galaxy SII's lens has focal length equivalent of 30mm.
 
Everybody will agree that 2.4 is better than 2.8 if everything else is equal.

I wouldn't agree than 2.4 is better than 2.8 if everything else is equal. Quite frankly there are times where I want f2.4 and there are times that I want f2.8 or slower.

2.4 is faster. Drinks more light.
Better sharpness, creamier bokeh for portraits.
better in lower light situations.
etc

f2.4 does not equal better sharpness, necessarily. Yes, it does mean potentially faster shutter speeds, but f2.4 gives you a shallower depth of field than f2.8, which means your subject might be not quite as sharp as you would like it to be at f2.8 or stopped down further.

e.g. I have a Canon 50mm f1.4 lens, and at f1.4 it's not especially sharp, but stopped down to f2.8/f4.0, it's so much sharper it's not even funny.
 
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