Digital camera in Aperture Priority mode does not change the depth-of-field

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I have a Panasonic Lumix TZ10 Digital Camera (see here)and although old and only 12MP it produces very good quality images.

I have been trying to use Aperture Priority mode with centre focusing and it seems no matter how low the f-stop is set I don't seem to be able to get a low depth-of-field - everything is in focus.

Can anyone suggest what stupid thing I have overlooked ?
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Commented:
What is the ISO set at?

Author

Commented:
I have tried changing the iso, as they are interlinked, and no value seems to change the DoF
the aperture range on this camera is f/3.3-f/6.3 (lower f-stops = greater aperture)
Focusing Basics
Understanding Depth of Field in Photography

the focal length range is 25 mm to 300 mm (the higher the zoom, the longer the focal length)
shorter focal length gives a wider frame angle
Focal Length and Zoom
Capture the whole image or focus in on the tiny details
The focal length of the lens (measured in millimeters) and the zoom ratio determine how much or how little of the scene you are photographing will appear in the final photograph. When you want to show the whole scene, you use a short focal length and when you want to focus on a detail you use a long focal length.

now you should be able to compose your pics with the appropriate depth of field, within the limits of your camera.

for a final tip, here is a link to a DEPTH OF FIELD (DOF) CALCULATOR
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Author

Commented:
Hi again,

Yes I instance how the depth of field works. My problem is that when I am using spot focus, in daylight (so iso is low), hold the shutter button half way down to focus on an object (say about a meter away from me)
everything in the background and foreground is in focus !

I have tried changing the f-stop over the entire range and nothing changes
and the zoom?

Author

Commented:
the zoom is fine
i meant i wanted to know if you are using the zoom ;-)

the REAL Objective focus length: 4.1~49.2 mm (35 mm equivalent: 25~300 mm)
if you play around with your Objective focus length and f/3.3-f/6.3 (lower f-stops = greater aperture) values, remembering that higher focus lengths mean MORE zoom, you will see the results
OP asks how to reduce the depth of field.

unfortunately, 'Aperture-Priority' mode alone will not accomplish this. it is necessary to use the optical zoom to increase the focal length

this is why i included the DoF calculator link (https://www.photopills.com/calculators/dof) to find the zoom/aperture combinations which will give the results he wants.

Author

Commented:
Paul: Thanks for the info. I have tried with various combinations of f-stop and zoom and nothing seems to work.

Even my Huawei Mate 22 lite smartphone's imitation of AP looks better than anything I can get with my TZ10. So when you say you need to use zoom I am confused. Do you mean you need to zoom with small f-stop to see DOF because all the videos online I have double checked before asking here show the ability to set AP f-stop while hardly (if at all) zooming and getting the DOF background blur.

Have been thinking for a while of getting a better camera. Can't afford a DSLR so was thinking of Bridge. What I need is something with a good zoom, with a 16MP+ image that gives me a good range of DOF to play with and good night photography. Optional extras as good video (occasionally used) and fast shutter speed for capturing those action moments. I have been looking for a while and been looking at this one: https://www.digicamdb.com/specs/panasonic_lumix-dc-fz82/. As, based on our other encounters, your very knowledgeable in this area can I ask if you think that is a good spec (especially the f-stop) ?

Many many thanks in advance.
Do you mean you need to zoom with small f-stop to see DOF because all the videos online I have double checked before asking here show the ability to set AP f-stop while hardly (if at all) zooming and getting the DOF background blur.
yes, you should try medium to high zoom with a low f-stop and select a subject to focus on close to the camera

here is a much better DoF calculator: https://alikgriffin.com/depth-of-field-calculator/

this is a site with great info an everything photography:
Digital Photography Review www.dpreview.com

Author

Commented:
Thanks Paul,

Yes I tired a medium zoom to focus on a plant about 1.5m away from me and set the lowest f-stop (3.3) but the background was still in focus.

I even displayed the photo on a computer rather than the back of the camera and the background was still in focus ! Very frustrating and annoying.


What was you opinion on the camera I suggested ? Enough of an f-stop range when combined with the long zoom ? Seems to have good reviews and the example photos on amazon (if genuine) have the background blur I am looking for but it has a small maximum f-stop. I would appreciate your professional opinion (even if you are retired).

Author

Commented:
The below more detailed spec looks good to me but I don't pretend to me an expert: Panasonic's details
what you are trying to achieve is called the "bokeh effect" -  have a look here to see HOW to do this:
7 ways to achieve a beautiful bokeh effect in your photos (with stunning examples)
If you frequent photography websites or have photographer friends, then there’s a good chance you’ve encountered the term bokeh before. Camera enthusiasts discuss this optical effect regularly, but what is it exactly? Taken from a Japanese word for “blur,” bokeh has become a photography jargon used to describe how a lens renders a background that’s out of focus.

the information here will give you the information you need to choose a camera to accomplish this!

Author

Commented:
Yes I know it is also called Bokeh. What I was asking is whether in your greater instating the combination of x60 zoom and the f-stop range on that Canara well be sufficient.

The example images from the camera seem perfect.
the article says
The reason why some people get frustrated with bokeh is that they're probably using the wrong lens. The secret to getting beautiful bokeh is using a lens that has an aperture of at least f/2.8. Unfortunately, the maximum aperture of a typical kit lens (the lens often found on entry-level cameras) only goes as low as f/4.5 or f/3.5. Although it’s more or less just two f-stops away from the ideal aperture, it’s still not wide enough to provide the background blur essential for bokeh.
...
So what type of lens should you use, then? For beginners, a 50mm lens is the best choice. It’s cheap, it’s easy to find, and its aperture opens up to f/1.8 or f/1.4. Apart from the ‘nifty fifty’, you can also use telephoto lenses to create hazy backdrops. Lenses with longer focal lengths increase the depth of field (also called DOF) even when the distance between the camera and the subject doesn't change. Coupled with a low f-stop (f/2.8 or lower), zooming into what you’re photographing with a telephoto increases blur significantly.

the camera specs (https://panasonicdirect.store.panasonic.co.uk/p-5129-panasonic-dc-fz82eb-k-dc-fz82eb-k-panasonic-lumix-digital-camera-with-ultra-wide-20-1200mm-lens-black.aspx?psn=5) say Max aperture: f2.8 - f5.9, so you're good to go!

this is what i have been trying to explain: small f-stop medium to high zoom

HOWEVER: the sensor size of your camera has an impact on the image recorded:
DIGITAL CAMERA SENSOR SIZES
This article aims to address the question: how does your digital camera's sensor size influence different types of photography? Your choice of sensor size is analogous to choosing between 35 mm, medium format and large format film cameras — with a few notable differences unique to digital technology. Much confusion often arises on this topic because there are both so many different size options, and so many trade-offs relating to depth of field, image noise, diffraction, cost and size/weight.

Background reading on this topic can be found in tutorial on ]digital camera sensors (www.cambridgeincolour.com/tutorials/digital-camera-sensor-size.htm).

Author

Commented:
Well I decided last night to go ahead and order it - so we will see
 It does have a minn f-stop of 2.8 so let's hope the small sensor size doesn't have to much of an impact.
please have a look here:
All forums>Panasonic Compact Camera Talk
Bokeh with FZ80
QUESTION:
Hi,
I just got a Panasonic FZ80 bridge camera. I have only had it for a day and know it is not my old Canon DSLR, but wondering if anyone can help with achieving best possible bokeh photos such as birds and flowers? I've not had success but will be going to wildlife park tomorrow.
...
ANSWER:
The camera has a 1/2.3 sensor with a lens with apertures 2.8 to 5.9.

It is not a good combination at all for de-focused backgrounds, especially at close range. Your best bet will be to be farther away from the subject and use longer focal lengths.

Camera sensor size: Why does it matter and exactly how big are they?sensors compared

Author

Commented:
Well I hope the camera proves better than your post would suggest as it's arriving tomorrow
Lumix DC-FZ82 Sensor size: 1/2.3" (6.17 x 4.55 mm)

Author

Commented:
Yes I appreciate that but on the other hand all the reviews are excellent and the (supposed) sample images have excellent Bokeh. So lets hope the newer model had improved.
i forgot to post the url for the bokeh discussion of the fz80: https://www.dpreview.com/forums/thread/4346411

you can see from the photos posted here the bokeh effect you can get using higher zoom & low f-stop

there is some good information for you to read!

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