How to Marry DOF and a Compact?

[modene1]

Hi,
After a ridiculously long time I've had to buy a new camera - a Canon PowerShot SX270 HS (spec here).

What I'm really struggling to do is create nice portraits (in and out) with minimum depth-of-field. Something that was a breeze on the SLR.

As you can see I have:

• f/3.5 - f/6.8
• 1/2.3 type back-illuminated CMOS

to play with.

I'm not overly familiar with these terms but was told these stats were important for DOF.

Can you help with specific cocktails of f-stop/ISO/shutter... or should I give up? Another possibility might be the 20x optical zoom (although not preferred).

Many thanks,

 

[Designer]

The factors that enter into the prospect of giving you a minimum depth of field are:

Longer focal length of lens

Wider aperture

closer to subject

If your new camera will not give you the results desired, you will need to figure out a way to change any or all of the factors.

 

[Braineack]

shoot at 90mm.

 

[JustJazzie]

Zoom in as far as you can without the optical zoom. And separate your subject from the background as far as you can!

 

[KmH]

Hi,

As you can see I have:

• f/3.5 - f/6.8
• 1/2.3 type back-illuminated CMOS

to play with.

The 1/2.3 image sensor size is the smallest they make, and it has a 5.62 crop factor.

The smaller an image sensor the greater the crop factor and the more difficult it is to attain a shallow DoF.
Digital Camera Sensor Sizes: How it Influences Your Photography

If by saying SLR you mean a 135 format (35 mm) film camera, then that was a full frame and there is no crop factor.

 

[Derrel]

Zoom in as far as you can without the optical zoom. And separate your subject from the background as far as you can!

There's a balancing act when one strives for the shallowest DOF possible withy a small-sensor compact camera: distance to the subject is very critical. The primary determinant of DOF will be distance to the subject; the closer you are to the subject, the better,even if that means sacrificing some of the zoom-in, make sure you are pretty close to the subject. And as jazzie mentioned, try and situate the shot so that the subject is close to the camera--and the background is far,far behind the subject.

Wide-open aperture will give less DOF, but on a 1 and 2/3 size sensor, there is plenty of depth of field at all aperture values at longer distances. My guess is that as the lens zooms all the way out the aperture losing physical diameter will increase the DOF, and that the least DOF might be achieve very close to the subject, with the lens probably no more than 1/3 of the way into the zoom range, to 1) keep the distance to subject short and 2) to keep the aperture pretty wide 3) to use not the widest-angle setting 4) to avoid needing to be 15 feet away at the tele end. Again, the balancing act.

 

[chuasam]

Easy:
Panasonic Lumix GM-1
Nikon Coolpix-A
Sony DSC RX-1

 

[modene1]

Easy:
Panasonic Lumix GM-1
Nikon Coolpix-A
Sony DSC RX-1

When can you send me the money?

 

[modene1]

@Derrel. Brilliant. Thanks for the full post. Much appreciated. Thanks also to the others

 

[chuasam]

Easy:
Panasonic Lumix GM-1
Nikon Coolpix-A
Sony DSC RX-1

When can you send me the money?

No! Use your own.

 

[bratkinson]

One of the things to consider is that point and shoot type cameras are not intended to satisfy the more critical DSLR customers. Instead, the goal is simplicity and least amount of difficulty to get acceptably sharp and properly exposed pictures regardless of the shooting conditions. Getting a 1"-2" DOF in a picture is not likely to be one of the major design considerations, whereas getting a 'family shot' of 12-15 people all in focus is important. I'd hazard a guess that the majority of non-photographer point and shoot owners don't even know what depth of field is. All they want are nice, sharp pictures better than what their cellphone can produce.

For what it's worth, my fairly recent addition of a Canon G15 as a 'bang around' camera (in addition to a 5D mark iii) has really surprised me in what it can do in 'Auto', regardless of the lighting. Although the lens on the G15 is f1.8-f2.8, I don't consider super-thin DOF one of its capabilities. Instead, the f1.8 is more likely an 'accommodation' for some really low-light shooting and only occurs at very wide-angle focal lengths.

 

[Raj_55555]

I would say Derrel & Jazzie covered the two basic points to get what you want. I've been shooting with sx50 (the big brother of SX270) for a few years now, but they use the same sized sensor so it should be applicable. I'll add a few of examples showing some of these cases for your reference.

Case1: Relatively close to subject, zoomed in as much as possible, background being close to the subject.

Case2: Very close to subject(macro), totally zoomed out, background being close to the subject.

Case3: Relatively close to the Subject, relatively zoomed in, background far away

Case4: Very far away from the subject, completely zoomed in, background far away

I do hope this helps!

 

[Solarflare]

1. Buy a Canon 5D3
2. Buy a Canon EF 85mm f1.2
3. GLUE the lens to the camera so it cannot be exchanged anymore. And voila, its now a compact camera !
4. Done. You have a compact with great DoF !

SCNR

 

[usayit]

Yes... I could also get subject separate with my old Panasonic LX3 but the subject has to be very far from the background.

I would recommend not fighting with the inherent limitation of small sensor compacts, after all compacts are great for being ...well.. compact in size. Simply do it in post. Alien skin - Bokeh plugin which is now part of their "Exposure" package has had some good reviews although I myself haven't used it.

Another interesting plug in?Alien Skin Bokeh 2 | STEVE HUFF PHOTOS

The alternative is to buy a camera more suitable for it....

 

[Derrel]

Wow-some GREAT posts from Raj and usayit and bratkinson. I looked at the Canon G15 a few weeks ago at BestBuy....DANG-! I WANT! I WANT! I had a G3 years ago, but gave it to my then teenage nieces when the reallly wanted a digital camera. I was utterly amazed at how gorgeous the G15 is, and how, well, how perfectly Canon has evolved the controls to be.

And usayit's suggestion of software blurring: that has become better and better,and I know one person on here, The_Traveler, who's pretty good at it. Raj's photos were really good illustrations.

I remembered this article/chart from late 2012 that dPreview did, with a chart describing background blur degree and its relationship to sensor size.

Background blur and its relationship to sensor size: Digital Photography Review

THE LEAST background blur? Very Limited blur, APple iPhone5. Next, Very Limited blur; then Limited blur for a whole host of compacts; Reasonable Blur for many cameras like the APS-C d-slrs and the 18-55 f/3.5~5.6 kit zooms; Strong Blur with several d-slrs; and Very Strong blur with the EOS 6D and 85mm f/1.8. So, that was the gamut the article encompassed. Pretty good one-pager as far as allowing people to SEE in photos, and to read about some of the factors underlying the degree of blur that goes with types of cameras and lenses.