What range of photos/depth of field would a 3.5 – 5.6 lens take?

[peach]

What range of photos would a 3.5 – 5.6 lens take? What would my depth of field be limited to? I need to buy a camera for school for digital stuff. So far I have just used the film camera and it has a wide range of settings for this. The lens on the mirror-less camera my friend is selling is 3.5 – 5.6. Would it be a better idea to look for something else?

[DanK]

Those numbers are almost certainly the maximum aperture (small number=wide aperture) of the zoom lens at different focal lengths, with the wider aperture (f/3.5) at the short end. That would only limit the narrowest depth of field you could obtain. You could get a wider depth of field by closing the aperture further, that is, a larger f/stop number, at the cost of letting in less light. However, the precise depth of field depends on more than the aperture. In particular, it depends on on distance to the subject.

This is explained in a very good tutorial on this site, https://www.cambridgeincolour.com/tu...h-of-field.htm. I suggest you read that first and then post questions afterwards so that we can clear up what isn't clear to you. It's more both more efficient and more thorough than our trying to re-write it all ad hoc.

At this site, we use real names and show our location. Could you please go to "my profile" at the top right and add that information?

[Manfred M]

What range of photos would a 3.5 – 5.6 lens take? What would my depth of field be limited to? I need to buy a camera for school for digital stuff. So far I have just used the film camera and it has a wide range of settings for this. The lens on the mirror-less camera my friend is selling is 3.5 – 5.6. Would it be a better idea to look for something else?

The answer is not all that simple as the sensor size and other concerns (distance to subject) will all impact depth of field.

This article is where you might want to start learning about DoF.


https://www.cambridgeincolour.com/tu...h-of-field.htm



You might find this DoF calculator to be useful.

https://www.cambridgeincolour.com/tu...calculator.htm

[Tronhard]

Hi Peach:

Your question is dependent on a range of factors that include the focal length of the lens. Also we don't know what kinds of subjects you want to take - depth of field varies with the focal length, aperture and distance to the subject.

If you belong to a library check out their on-line catalogue and see if they have an item for lynda.com. If so you can log onto this site for free using your library credentials by clicking on the library listing. Alternatively you can go to lynda.com and use the button on the top right to get a month's free access.

lynda.com has an amazing array of on-line videos and tutorials about many subjects including photography. Each video is kept short and is presented by an expert in the field and if you are studying digital photography at school this will be an invaluable resource.

If you can get in there I recommend the following link:
https://www.lynda.com/SharedPlaylist...8-e7088633bb78

Check out the first two videos in the list.

[Shadowman]

I would also find out if specific camera type is needed/recommended for the class.

[William W]

. . . I need to buy a camera for school for digital stuff. So far I have just used the film camera and it has a wide range of settings for this. . .

I've taught Photography to High School Students. If you want advice about what DIGITAL camera to buy for your school lessons, then, whilst there might a consideration about what Depth of Field is achievable, there will probably be other considerations that will be more important, and likely more relevant to the Photography Course you intend to undertake.

When you return to this conversation and answer to the questions posed above, it would also be beneficial if you clarify your position as to being a Student or not - and an outline of the course you're taking would be a good idea too.

WW

[dem]

What range of photos would a 3.5 – 5.6 lens take?

If you look at kit zoom lenses for different sensor formats (I used examples from mirrorless cameras):

m43: Olympus 14-42 (f/3.5-f/5.6)
APS-C: Sony 18-55 (f/3.5-f/5.6)
Full frame: Sony 28-70 (f/3.5-f/5.6)

you will see that they all have the same largest aperture at the wide end (f/3.5) and the same largest aperture at the telephoto end (f/5.6). With any lens you can always close the aperture down to f/8, f/11, f/16 to whatever the smallest aperture on the lens is.

All kit lenses above also give about the same range of angles of view that covers (but might not be optimal for) most shooting scenarios from landscape to portraiture. That's why these lenses are supplied as "kit" lenses.

What would my depth of field be limited to?

This mainly depends on the sensor size. At the same aperture, say f/3.5, you might have a depth of field 2 meters on m43, 1.5 meters on the APS-C and 1 meter on full frame. Note the dof ratios 2:1.5:1 follow exactly the crop factors for these sensors. Increasing the depth of field is not a problem on any format with any lens. Decreasing is - you will have to use bigger sensors and faster lenses to make DoF more shallow. This should not be the whole objective of your photography by the way. I would think any kit lens on any format is good enough to start you off, but do check with the school.

[rpcrowe]

The f/numbers alone do not tell you what the depth of field would be with any given lens...

The factors involved in determining depth of field are:

1. Focal length of the lens
2. Distance focused on
3. Sensor size
and
4. f/stop you have chosen to use. This is most often a smaller size aperture than the maximum apertures of your lens which are: f/3.5 at the widest focal length and f/5.6 at the longest focal length for the lens you are considering.

The f/stop is a fractional representation of the size of the aperture compared with the focal length of the lens. That is why the f/stop is written as f/. It is a fraction.

Many of today's lenses are variable aperture which means that the f/stop is wider (smaller f/number such as f/3.5 for the lens that you are considering) at the shortest focal length and less wide at the longest focal length (larger f/number such as f/5.6 for the lens you are considering).

It may seem counter intuitive but lenses that do not adjust size of the the aperture for focal length are variable focal length lenses. Just consider it this way: If you have a lens of 100mm focal length with a constant maximum aperture of 25mm, that lens would be considered an f/4 lens (25mm / 100mm = 1/4 or f/4) if I decrease my focal length to 50mm while still retaining a maximum aperture of 25mm I would have an f/2 lens (25mm / 50mm = 1/2 of f/2).

Most photographs are not shot at the maximum aperture of a lens. Instead the lens is stopped down (aperture made smaller) at the choice of the photographer of of the camera when you are in an automatic mode. Therefore an f/3.5 lens can shoot at smaller apertures (which would let in less light, require a slower shutter speed and provide a greater depth of field) but, f//3.5 is the widest aperture that can be used.