Help me choose a Compact Digital - Depth of Field and other Considerations

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Andy
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Further to a recent thread I am still trying to decide on which compact to get for a trip to Thailand in the New Year.

One thing I am very keen on is the ability to have a shallow depth of field which immediately made me think of the Canon G1X and Sony RX100 because of their larger sensors, but it looks like this advantage might be negated by their maximum aperture at full zoom. As far as I can see the extra zoom of the Nikon P7700 means that it has a shallower depths of field at the long end.

OR HAVE I MUSUNDERSTOOD THINGS???:shrug:

The Panasonic LX7 and Olympus XZ-1 appear to make a reasonable fist of things as well but I think it’s going to be a three horse race.

I got the DOF info below off the internet . Am I missing anything?

Canon G1X
Depth of Field @ 5ft “Wide” 3.85-7.14; @ 5ft “Tele” 4.82-5.19; @ 30ft “Tele” 24.4-38.9

Pros
Has optical viewfinder for bright conditions
Nice big sensor
Depth of field consistently good

Cons
Bit of a lump (I know part of that is due to the viewfinder, I guess Canon can’t win)
4x Zoom

Nikon P7700
Depth of Field @ 5ft “Wide” 3.32-10.1; @ 5ft “Tele” 4.90-5.1; @ 30ft “Tele” 26.7-34.2

Pros
7x Zoom
Depth of field “Tele”
Compact

Cons
Depth of field “Wide”
No viewfinder (Nikon can’t win either)

Sony RX100
Depth of Field @ 5ft “Wide” 3.94-6.84; @ 5ft “Tele” 4.73-5.3; @ 30ft “Tele” 22.3-46

Pros
Looks stunning
Depth of field “Wide”
Compact

Cons
Only 3.6 Zoom
Depth of Field “Tele”
No Viewfinder (yeah yeah, I know:bang:)

Panasonic LX7
Depth of Field @ 5ft “Wide” 3.34-9.91; @ 5ft “Tele” 4.74-5.29; @ 30ft “Tele” 22.5-45

Pros
Price

Cons
3.8x Zoom

Olympus XZ-1
Don’t have DOF data for this but I expect it to be similar to the Panny. Same Pros and cons too.


What else??
I want the ability to shoot RAW which I think all the above can do. Obviously there are loads of other features / differences between the cameras which I am trying to get my head around. One feature that is missing from them all (and which would be a real deal maker) is weather proof seals per the Pentax DSLR’s, oh well, maybe next years models.

I don’t want to make it sound like I am going to buy just on the basis of a technical spec but once I have got my head around balancing the pros and cons identified so far I will hopefully be on the way to opening up my wallet.

Now there might be new releases in the pipeline that I’m not aware of, ready to throw a spanner in the works, but at the moment my heart says Sony:love: but the zoom range of the Nikon is very hard to resist.:thinking:

What to you guys think?

Stumps
 
With smaller sensors you'll be using wider lenses and the same rules apply, to get limited DoF you're going to have to use/balance the longest focal length you can, the widest aperture and reduce the camera to subject distance.

With something like a 6mm equiv FoV you've got next to no chance of getting limited DoF. You could go for the (relatively) larger sensor and a (relatively) long lens and accept the compromises that places on your framing, or just forget about chasing thin DoF. MFT @20mm f1.7 might be enough?
 
Hi Woof Woof,

Apologies for ignorance but "MFT" means??

Stumps
 
Micro four thirds.

Depth of field is proportional to sensor size. The bigger the sensor, the easier it is to get it shallower - but you do need the right lens to enable it.

People very often mistake depth of field (i.e. the bit of the photo you perceive to be critically in focus) with the bokeh of the shot (the quality and "blurriness" of the out of focus areas).
 
Easy way to work out relative DoF between formats, using the crop factor.

Find out the 'equivalent' focal length in full-frame terms, and divide that by the actual focal length. For example, Nikon P7700 has a 6.0-42.8mm f/2-4 lens, equivalent focal length 28-200mm. Divide 200 by 42.8 and the crop factor is therefore 4.67x.

Multiply f/number by crop factor and in DoF terms f/2-4 x 4.67 converts to f/9.3-18.7. Hence the problem getting shallow DoF out of smaller format cameras.
 
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By shallow depth of field I am assuming you want the main subject to stand out and the background to be out of focus.
Some compacts or smaller sensor cameras have inbuilt software that can emulate this in some situations. Fuji X10 can and is very effective, but you still need a reasonable distance between the object and the background so this can work.
If you have time, pick a few of the cameras that interest you and look on Flickr for their group sites. You should get an idea what types of images they are capable of then.
Allan
 
Pity you need a zoom lens (assuming you do?) as the X100 would have been perfect.
 
arad85 said:
Micro four thirds.

Depth of field is proportional to sensor size. The bigger the sensor, the easier it is to get it shallower - but you do need the right lens to enable it.
Click to expand...

Here we go again... :D

Smaller sensors are often coupled with shorter lenses and... deeper DoF, would be a more accurate answer IMVHO :D

It doesn't matter if you have a 6mm, MFT, APS-C or "FF" sensor if your lens is a 6mm f4, IMVHO, you're always going to struggle to get shallow DoF.
 
woof woof said:
Here we go again... :D

Smaller sensors are often coupled with shorter lenses and... deeper DoF, would be a more accurate answer IMVHO :D

It doesn't matter if you have a 6mm, MFT, APS-C or "FF" sensor if your lens is a 6mm f4, IMVHO, you're always going to struggle to get shallow DoF.
Click to expand...
That is true, but isn't the point. And funnily enough, in that case, the MFT will give the shallowest DoF for a given print size, but the photo wouldn't be the same. What I haven't yet convinced you of (even though the maths shows it) is that sensor size plays a part.

If you use any DoF calculator or any DoF guides on a lens, the size of the sensor is built into the calculations - not through the f number or focal length (they are there too) but through another parameter: Circle of Confusion.
 
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