Depth of field
Discussion
Im having problems with depth of field. When taking still shots of people, or moving shots of bikes (Ive been at Oulton Park last weekend), im finding that everything is in focus. Now I did think that aperture made a difference in depth of field, but obviously it just blows everything out in bright light, and I cant seem to find any depth in any of my shots. Im using a Panasonic FZ7 Bridge cam, not a DSLR. Is this what is causing the problem or is it me?
Aperture does indeed make a difference to DOF, but it also makes a difference to exposure unless you counter it with the appropriate shutter speed.
My hunches:
1) You've got the camera in manual mode, have cranked open the aperture as wide as it will go but haven't increased the shutter speed faster to compensate.
2) The camera is set to too high an ISO, like 1600, and the bright light just swamps it.
Am I warm?
My hunches:
1) You've got the camera in manual mode, have cranked open the aperture as wide as it will go but haven't increased the shutter speed faster to compensate.
2) The camera is set to too high an ISO, like 1600, and the bright light just swamps it.
Am I warm?
Edited by Simpo Two on Friday 8th May 22:00
3 things make up the Depth of field.
Aperture - you want as large (smaller number) as you can.
Focal length - longer the better/shallower DOF
Focal point - closer to the camera the shallower DOF.
So shoot 'wide open' at the long end of your lens and with the subject close - also helos of the background is a fair distance behind them.
Use potrait mode will basicaly whackthe lens wide open too.
Aperture - you want as large (smaller number) as you can.
Focal length - longer the better/shallower DOF
Focal point - closer to the camera the shallower DOF.
So shoot 'wide open' at the long end of your lens and with the subject close - also helos of the background is a fair distance behind them.
Use potrait mode will basicaly whackthe lens wide open too.
Say I was shooting with an aperture of F2.8 then what kind of shutter would I be needing to use on a bright sunny day? I generally dont use an ISO higher than 200 as the camera tends to get grainy above that. Im just having issues with exposure at the moment and I need to sort myself out. I think I need to go back to the drawing board, and keep on practising. I'd really like to get myself a DSLR but its a budget thing at present. I prefer to use the viewfinder rather than the screen and with the Panasonic, the viewfinder is digital and therefore doesn't really show the end product.
Rob13 said:
I dont think the Fz7 will shoot at those shutter speeds at shorter depth of fields. The lowest is F2.8 for the camera - will regular DSLR lenses shoot at wider apertures?
Depends on the lens. On a std kit lens at the long end the minimum apperture maybe as slow as F5.6, yet a cheap £80 50mm lens on most camers will give F1.8. Usually the fastest lens you find is F1.4 (nikon), F1.2 (canon), though Canon did make an F1.0 lens, though that's obviously for lucky gits only... ;o)Can you answer my two questions?
Rob13 said:
I dont think the Fz7 will shoot at those shutter speeds at shorter depth of fields. The lowest is F2.8 for the camera - will regular DSLR lenses shoot at wider apertures?
You're getting in a bit of a mess here. I think your problem is that your camera can't give a sufficiently fast shutter speed to make a correct exposure in bright light at f2.8. That is why it's overexposing. By trying to get a wider aperture for shallower DOF (eg f1.8) you will only make the problem worse. In summary, you're trying to achieve something your camera isn't able to do, and yes, a DSLR will do it. But you do need to put some time in grasping the basics first I feel.Bridge cameras tend to have very small sensors and you will really struggle to get much DoF effect even if shooting close up in macro mode.
I have a Canon S3 IS which just about gives a blurred 'DoF' background effect using the lens at or around its 432mm zoom mark and something like its shortest focus distance at that length.
What you are getting will not actually be sharp well beyond the subject but will look like it is sharp enough in most cases. The eyes will be fooled. Even a regular (i.e. not a full frame) DSLR will tend to have greater DoF sharpness then people might want. Once you get to 600mm things start to get easier in the bokeh department.
If you are reasonably good at visualising distances there are a couple of DoF calculators on the net that take all the factors, including sensor size, into account and will give you back some numbers to work through.
I have a Canon S3 IS which just about gives a blurred 'DoF' background effect using the lens at or around its 432mm zoom mark and something like its shortest focus distance at that length.
What you are getting will not actually be sharp well beyond the subject but will look like it is sharp enough in most cases. The eyes will be fooled. Even a regular (i.e. not a full frame) DSLR will tend to have greater DoF sharpness then people might want. Once you get to 600mm things start to get easier in the bokeh department.
If you are reasonably good at visualising distances there are a couple of DoF calculators on the net that take all the factors, including sensor size, into account and will give you back some numbers to work through.
Simpo Two said:
Can you answer my two questions?
I was running it on manual and trying to use a wider aperture and then ramped the shutter speed right up (was trying to take a shot of a moving bike so I wanted a fast shutter anyway) but it was blown out. I think that was at 100 or 200 iso at that time.Rob13 said:
I dont think the Fz7 will shoot at those shutter speeds at shorter depth of fields. The lowest is F2.8 for the camera - will regular DSLR lenses shoot at wider apertures?
You're getting in a bit of a mess here. I think your problem is that your camera can't give a sufficiently fast shutter speed to make a correct exposure in bright light at f2.8. That is why it's overexposing. By trying to get a wider aperture for shallower DOF (eg f1.8) you will only make the problem worse. In summary, you're trying to achieve something your camera isn't able to do, and yes, a DSLR will do it. But you do need to put some time in grasping the basics first I feel.Ive had the camera a while now, and still my exposures are hit and miss. I try using the graph display to give me an idea of where I am in the shot. I shoot my landscapes mainly in aperture mode (should I be using manual?) and I use EV compensation to alter the exposure. Should i be looking to run it in manual and using aperture and shutter and avoiding EV compensation?
Can anyone give me any pointers as to what I should be doing? I feel i'm grasping the basics, but dont seem to be improving
Sounds like you are tryin the right things. for the exposure wide aperture, low ISO, high speed.
EV adjustment will just fix the Av and tweak one of the other values (most likely) for you.
I would guess Simpo is right. The camera make lack sufficient dynamci range to give what you want when porocessed as a jpg. The jpg processing is likely the only other variable. Are you specifying an particular sort of preset ( I assume the FZ7 does not have RAW?).
You may be able to improve things with some post processing work. Difficult to tell without seeing.
EV adjustment will just fix the Av and tweak one of the other values (most likely) for you.
I would guess Simpo is right. The camera make lack sufficient dynamci range to give what you want when porocessed as a jpg. The jpg processing is likely the only other variable. Are you specifying an particular sort of preset ( I assume the FZ7 does not have RAW?).
You may be able to improve things with some post processing work. Difficult to tell without seeing.
Without seeing the output it's difficult to tell, but a snip from one of the online guides tells me
cameras.co.uk said:
You can take full control over the exposure by using the fully manual exposure mode. Aperture priority and shutter priority are available too. Shutter speed can be set in the range 60 - 1/2000 seconds. Available apertures are in the range of Wide: F2.8 - F8, Tele: F3.3 - F8.........ISO sensitivity (Auto/80/100/200/400 High Sensitivity Mode: Auto / 800 / 1600)................ The 12x optical zoom lens has a focal length of 36-432mm in 35mm format
I think if you're on big zoom for motorsport it's not going to let you get anywhere near F2.8, not that you necessarily need that for DoF mind. Stick some photos up, it'll be easier to understand what you meanLongQ said:
Bridge cameras tend to have very small sensors and you will really struggle to get much DoF effect even if shooting close up in macro mode.
This is the issue I believe. The small sensor on the camera means you get vastly more depth of field than a dSLR given the same aperture. Macro mode on your camera will result in DoF but this limits your shooting possibilities!This is true when comparing the difference between DX and FX dSLR's but is less pronounced.
Unfortunately its simply a question of physics.... time to upgrade to a dSLR
Good excuse imho Rob13 said:
I was running it on manual and trying to use a wider aperture and then ramped the shutter speed right up (was trying to take a shot of a moving bike so I wanted a fast shutter anyway) but it was blown out. I think that was at 100 or 200 iso at that time.
Ive had the camera a while now, and still my exposures are hit and miss. I try using the graph display to give me an idea of where I am in the shot. I shoot my landscapes mainly in aperture mode (should I be using manual?) and I use EV compensation to alter the exposure. Should i be looking to run it in manual and using aperture and shutter and avoiding EV compensation?
Can anyone give me any pointers as to what I should be doing? I feel i'm grasping the basics, but dont seem to be improving
Hi Rob,Ive had the camera a while now, and still my exposures are hit and miss. I try using the graph display to give me an idea of where I am in the shot. I shoot my landscapes mainly in aperture mode (should I be using manual?) and I use EV compensation to alter the exposure. Should i be looking to run it in manual and using aperture and shutter and avoiding EV compensation?
Can anyone give me any pointers as to what I should be doing? I feel i'm grasping the basics, but dont seem to be improving
You've got all the right basics but not quite linking them together properly. In this case you've simply run off the scale of what your camera can do (unless you use an ND filter as mentioned above).
Shooting in manual means the camera's metering system is not being involved; it will simply do what you tell it, whether right or wrong. There's no point in using EV as well; it's like cutting a bit of wood too short then adding a new bit on.
I shoot 98% of my work in aperture-priority auto, meaning that I choose the aperture (so I'm choosing DOF, and also indirectly shutter speed as well). If it's not quite right, then consult the histogram (graph) and use EV as required, typically +0.5 but it depends on the situation and of course your camera.
Purists will often say 'Bah, use manual' - but it's not essential and as you've found, can often make things much harder. I only use manual exposure when using studio flash - because the camera and the flash heads work independently.
So try abandoning manual exposure for now, and try aperture-priority. But really, as has been said, you're too advanced for your camera and should consider a DSLR
Ansel Adams book 'the camera' is extremely good, not just at explaining the basics. Although it was written a good few years ago, its still as applicable in the digital age. Recommended reading for anyone with a camera really. I'd think there were a good few photgraphers who would have something useful to learn from it. 'The Negative' also by Ansel Adams is worth reading too but about half is dedicated to the darkroom, which in the digital age is redundant for most people.
If your exposures are 'hit and miss' then using manual exposure for a while will help to understand the relationships between f-stop/shutter speed and the final result. Somthing thats invaluable and with digital pretty quick to learn as you can look at the image youve just taken, not wait to get home and develop the film to see your mistakes.
If your exposures are 'hit and miss' then using manual exposure for a while will help to understand the relationships between f-stop/shutter speed and the final result. Somthing thats invaluable and with digital pretty quick to learn as you can look at the image youve just taken, not wait to get home and develop the film to see your mistakes.
Thanks for all the feedback. Like I said, I have shot most of my stuff in aperture mode, keeping the iso as low as possibly to reduce any grainy issues. 400 iso is the absolute maximum I use on the camera. I usually use 80 or 100 if i'm outdoors.
When using Aperture priority mode and shooting landscapes, what factors must be considered? Im obviously not looking for depth of field in wider angled shots so should i just let it all out or should I shoot around F4-5 to get a shorter shutter but without losing depth in focus?
It does sound like im doing the right things, as ive been reading the posts on here, stuff in books etc but dont seem to be getting the same results. Maybe Im looking at shots which have been shot in RAW and post-processed. Thats something which the Panny lacks, and yeah maybe I should be looking to upgrade its just getting the finances together to head into the world of DSLR.
When using Aperture priority mode and shooting landscapes, what factors must be considered? Im obviously not looking for depth of field in wider angled shots so should i just let it all out or should I shoot around F4-5 to get a shorter shutter but without losing depth in focus?
It does sound like im doing the right things, as ive been reading the posts on here, stuff in books etc but dont seem to be getting the same results. Maybe Im looking at shots which have been shot in RAW and post-processed. Thats something which the Panny lacks, and yeah maybe I should be looking to upgrade its just getting the finances together to head into the world of DSLR.
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