Watery Grave

[finescalerr]

The camera settings are fine. The meter is just fooled by the backdrop so give it a longer exposer next time and you should nail it. -- Russ

[marc_reusser]

Um...under aperature priority, I don't think it's possible to do that?...isn't that the whole purpose of AP?

Should I set it to shutter priority?

[Hauk]

Um...under aperature priority, I don't think it's possible to do that?...isn't that the whole purpose of AP?

Should I set it to shutter priority?

No, that will not help.

On my Canon G12 I use the aperature priority setting (and almost always choosing f 8.0 as this is the smallest aperture on this camera, and hence gives the optimal depth of field).

When I shoot with a white background I set the exposure adjustment wheel from +1/3  to +1 1/3. Or even +2 if the white background is dominating the motive. (I do not know the correct term for this wheel, so I include a picture.)

And when shooting with an dominant black background I set the wheel to between -1/3  to -2.

A classic camera light meter have no idea on what you are shooting. So at some time in history it was decided that an average motive reflects 18% light. A representation of this average motive is a Kodak grey card. If you take a picture of this greycard with an automatic, non-compansated setting, the exposures shall in theory be perfect.

A white sheet of paper or an white background is of course a lot lighter than the average motive (the grey card). But the light meter thinks that all motives are like a greycard, so you get an underexposed picture.

And with a black background the situation is reversed. The light meter again gives a reading that is correct for the grey card, and you get an overexposed picture.

This is at least how the situation was with old fashioned analog cameras. But the basics apply for modern digital cameras as well.

Did this make any sense?
Bottom line is: When shooting motives with large areas of white,  find a way to "overexpose" your picture up to 2 stops.

[marc_reusser]

Thanks Hauk,

I realized the exposure issue, probably as you wrote your post, when I tried running a RAW image through the Digital Negative Converter, and saw how much better it looked when I even upped the exposure. +.5 to .75. Great info on the camera default exposure settings....this is something that has been vexing me for a long time....no matter what I tried, I was always ending up with a slightly greyish/dingy looking white background, that needed cleaning in PS....I will up the camera exp setting a bit.

Now...still confused with the F stop though..........I thought Russ always says set it to the highest setting....which for me is rounf F36........this seems to give me very good depth of field, even on really close shots (granted, I have not tried F-8)

Marc

[lab-dad]

The larger the number(smaller aperture) will give the greatest dof.
However, many lenses have a "sweet spot" where clarity is best.
I think what he was saying was f8 was his cameras limit.

There is an excellent app called dofcaculator

Marty

[Andi Little]

Marc' - F36 will give you a good depth of field.... waaay too much in fact. You only need as much as is necessary to envelope the subject.
At F36 you've almost certainly got from right in front of you to infinity - [and beyond]. This will explain the infinity symbol on an old manual film camera.
F8 might only give you about a foot of focus, but if your subject fits within that foot once focused, then everything else is a waste anyway - well that's the simple version.
The problem is if you open up to F2 or the like to get max' light, probably the focus [or depth of field as it's known] won't cover your subject and the rear of it will likely be out of focus - hence "stopping" down and lengthening your shutter opening to compensate.
F36 to shoot something less than a 1/4 inch deep really is a sledgehammer to crack a nut ............... and why do I think you know this - or thought you did!!! I must admit to thinking you were a bit of a techno'-god with stuff like this??

My excuse is I'm a dinosaur [and bliddy proud of it - I've earned the right of irascibility] ... I used to teach photography back in a previous life [just as a supportive element] but then they digitalised it and my Brian - [I know, but my brain is called Brian] abjectly refused to make the switch and understand - in anyway shape or fashion.

I'm sure someone will come along and explain in better detail ... but it'll amount to the same thing.

Love and stuff.......................

[SandiaPaul]

Wow what camera do you have that has f36???

Paul

[Hauk]

Now...still confused with the F stop though..........I thought Russ always says set it to the highest setting....which for me is rounf F36........this seems to give me very good depth of field, even on really close shots (granted, I have not tried F-8)

Marc

Russ is absolutely right, the higher f-stop, the better depth of field.
On the G12 F-8 is the highest aperture setting, and will give the best depth of field *with this camera".

So regardless of what camera or lens you use, go for the highest f-stop when you want maximum depth of field.

[marc_reusser]

Thanks guys for all the help and input. Very much appreciated.

Marty: Thanks I will look into the app.

Hauk: Thanks for clearing that up, ws confused because like with your camera, my last one went to F-8, and part of the reason I bought this one was the e higher F stop capbility......and thus I thought I was now a doofus for having been concerned about that.

Andi: You accord me way to much skill and knowledge....and photography/camera settings has always been one of those things that I for some reason I absolutely can't grasp the concept of.....no matter how hard, or often, I try (color theory is another big one)......so as with numerous other things I just manage to muddle through it, or find a work-around, that gets me to the result I want. I agree that the F36 is overkill for what I was shooting.......usually I shoot t around F29...stil overkill for the boards, but it is generally easier for me to leave this setting  from a prior shot...otherwise I forget to re-adjust it, and then end up with funky pics in. Later shoot...and have to reshoot (not always possible onan SBS.)

Paul: It's nothing super special. It's a Sony SLT A-57. It gave me everything that I felt/thought I needed for model nd work photogrphy.   I chose it in large part for the whole image/screen/display thing (the display doesn't show what you are looking at through the lens....but rather the digital image, according to your settings/adjustments you have mde in the camera.......so the basic end product. It also has (coming from my last non-SLR camera) a lot of nice/useful functions/setting options and refinements. (Which I am still getting the hang of).

[finescalerr]

Marc, on your camera the exposures compensation (or bracketing) tool probably shows up in the viewfinder (as on Havard's camera, usually -2 to +2 stops but your fancy SLR may go from -3 to +3). When you shoot, do everything just as you have but fire off a couple of extra shots, one at +1 and the other at +2. -- Russ

[michael mott]

Wow all this is giving my Brownie hiccups

Michael

[Hauk]

Wow all this is giving my Brownie hiccups

Michael

If you use a  light meter with your Brownie, the discussion about bracketing when shooting against white or black backgrounds should be valid. But even the most advanced Brownie might not be very suited for model photography...

The principles regarding depth of field is also valid for any camera. Analogue or digital, it does not matter.
But there are variables that decide how much depth of field you will get.
These are:

• f-stop
• focal length of the lens
• format of film/physical size of sensor
• subject distance

f-stop
The smaller the aperture, the better the d-o-f. It is a bit confusing that a larger number means a smaller aperture. This is because the f-stop number is really a fraction. f-8 means that the aperture opening is 1/8 of the focal length of the lens. So for maximum d-o-f we want a physical opening in the lens that is as small as possible. Some modelers have gone as far as modifying SLR lenses with pinhole apertures to get better dof. A thin blackened disk with a tiny hole is inserted in the lens, and this way it is possible to get f-stops  down to maybe f-120. A small aperture lets less light pass through your lens, so you will need long exposures. That's why a tripod and good lighting is so important when shooting models. As have been mentioned already, the smallest aperture is not the optimal f-stop for anything else than the d-o-f. You get the optimal quality of a lens when using an f-stop that is the middle value for the lens.

Focal length of lens
Shorter focal lengths give better d-o-f.  So a wide-angle lens gives better dof than a telephoto lens. When you zoom in you loose dof.  

Format of film/size of sensor
This might be the trickiest one to explain. You might have heard that people claim that cheap compact cameras gives better d-o-f than expensive SLR cameras.  Often this is true. More expensive cameras have bigger sensors. A cheap camera with a tiny sensor uses a shorter focal length to achieve the same picture angle as a camera with a larger sensor. Now I hear brains popping, so here is a link to an article describing the concept of picture angles better than I could ever do.
But you might have heard talk about "Normal lenses". This is a lens with a picture angle of about 46deg. This is comparable to what we see with our bare eyes. So the "normal lens" (or zoom set to the "normal") on a cheap camera with a small sensor will have a shorter focal length than on a more expensive one with a larger sensor.  With the shorter focal length f-16 might give the same d-o-f as f-32 on the  camera with the larger sensor and longer focal length. I remember that when I first started to use Hasselblad cameras in photography school I was very disappointed with the d-o-f on this very expensive camera. Up to then I had only used SLR cameras with 35 mm film. The Hasselblad uses a much larger film format, 60mmX60mm. On my SLR I used a 35mm lens as my standard lens, on the Hasselblad I chose a 90mm lens. At the time I did not realize that I would have to use a much smaller f-stop to achieve the same d-o-f with the Hasselblad. And when advancing even further up to field cameras with 4"X5" sheet film you had to use around f-90 to get comparable d-o-f with the normal lens (which is a 180mm lens if I remember correctly).
So it is not really the smaller size of  the film/sensor that gives better d-o-f, but the fact that you can use a shorter focal length to achive the desired picture angle. And a shorter focal length gives better d-o-f.  But remember, we are talking only d-o-f here, so I am not claiming that a smaller image sensor/film format is generally a good thing! On all other counts, bigger is better.

Subject distance
Shooting closer to the subject means less d-o-f.
Have you ever seen one of those videos that make real scenes look like models? The main trick is faking a lack of depth of field.  So they simulate the fact that models are shot at much closer distance than real subjects. As modelers we do the exact opposite when trying to get as realistic model photos as possible.
A picture of a prototype scene shot in broad daylight will almost  always have a depth of field that goes from the closest to the furthest objects.


A fun fact I have never seen mentioned in articles on model photography is that if you used a working scale model camera you would get exactly the same d-o-f as If shooting the real thing. Lets say you shoot an O-scale building. You place your O-scale camera at 1/48 of the distance you would have used in real life.  A smaller subject distance gives less depth of field, but this is exactly compensated by the fact that the model camera´s lens have an aperture that is also 1/48 the size of the real deal. Remember, it is the smaller *physical* size of the aperture that gives better d-o-f.  The f-stop *number* is the same on the model camera as on the  full-size camera. The f-stop number is the relation between the focal length of the lens and the physical size of the aperture opening.  
As the focal length of the model lens is scaled down as well as the sensor/film size so you get a picture angle that is the same as the prototype lens. Of course, with a film format/sensor size as small as on this model camera, you would need to make an absurd enlargement to get a decent sized print. But the depth of field would be just fine!

Was this at all helpful, or should I go stand in the corner?

[mad gerald]

... When you shoot, do everything just as you have but fire off a couple of extra shots, one at +1 and the other at +2. -- Russ

... that's what I've learned recently (using my new camera) ... some times I take shots at -2, 0 and +2 (depends on) ... and I'm curious what similar pics would look like beeing shot in HDR mode ...

Was this at all helpful,

... yup, thanks for the explanation ...

Cheers

[lab-dad]

I have recently been working with HDR.
Sometimes combining as many as 7 images.
If you go to my webpage all the images in the "hdrrods" gallery are.
There are several in the other gslleries as well.
It is a fun process but not for every subject or personal taste.
I think i did and hdr of my willamette when i finished it too.
Marty

[Andi Little]

Great work Marty ...........

Those HDR images always remind me of those Photo-realist painting you see - really plays tricks with your mind. Well it does mine because I naturally "read" imagery and they act almost as a Trompe l'oeil does, but doesn't have anything [physical constructive structure] to hang onto whilst making your way around the piece - I do find them most disconcerting.
As too the Photo-realistic painting in truth. I'm always terribly impressed by them - the skills and execution: but I invariably find myself completely devoid of emotional stimulus - Now Andrew Wyeth - that photo realism sends me into some kind of drooling frenzy ... that is what one might call "good".

I'll have a further look around your web pages when I have more time - in fact I'll look forward to it.

Cheers for now.