# Depth of field and exposure.



## Gary (May 21, 2004)

About 3 weeks ago I couldnt find the "M" on my dial let alone know what to do in anything but automode. I tried reading books but my attention span is pretty short. So I just started shooting and trying different settings to see what happens. To my untrained eye, these look ok but seems a little thin.

Suggestions welcomed.

BTW, these are untouched besides re-sizing them. I want to learn how to take photos before learning computer touch ups.


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## galbayfisher (May 28, 2004)

First of all, if you are in manual (M), I assume you also have an internal exposure meter with some indicator that tells you that the picture is at the correct exposure, that is per aperture, shutter speed based on your iso. 

Depth of field and focus touch on a photograper's idea of composition and what he feels is important or what he would like others to SEE in his shot. One uses the aperture to do that. You might think of your eyes and eyelids as a natural aperture.
HINT: If you're squinting, are you letting more light into your eyes than before and by squinting, do objects become more in focus or not?

So, let's say in shot number 3, you wanted to stress the importance of that shock absorber(?) there in the front. I would first zoom in on the SA until I had it in focus. Second, open up the aperture until you get the desired amount of blur in the background leaving the SA in focus. Now, I am assuming that your camera has a depth of field preview which will allow you to see this. No matter.

Then, adust the shutter speed until your exposure meter says the pic is properly exposed. Let' say that orginally, at proper exposure, the shutter was around f/8 and you took it to f/2. That means you let in more light. That means you have to speed up the shutter to compensate for the "excess" light. Therefore, if the shutter speed was at say 1/125 of a second, you may have to take it to 1/250 or 1/500 of a second to be at the right exposure. Want everything in focus, do the reverse. Make sense?

Rule of thumb. if you want to blur the background, use apertures going toward the small numbers like f/4,2,1.8 etc. If you want everything in focus, then go towards the larger numbers f/16, 32 etc. Then set your shutter appropriately.

hope that helps.


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## RustyBrown (May 29, 2004)

*???*

Gary,

I'm not sure what you mean by "a little thin". If you're referring to the depth of field being thin by shooting at f/32 like you did then is no more dof to be had unless you change the subject distance. The dof distance increases as you increase the distance the subject is away from the lens. The downside is the subject gets smaller.

I'm assuming you're shooting the 105mm macro lens. These lenses are designed to function best in a small dof range. I agree with GalBayfisher that in your case you might want to go the other way and reduce your depth of field to "force" the viewer to look at one component.

Because my strength (I think) is in landscape imagery I'm a big dof guy. In regard to learning the postprocessing side look at the color difference between shots 1 & 2. One thing at a time for now though.


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## Gary (May 21, 2004)

What I ment by thin is, the colors just didnt pop out at me. I guess I could change that with the pc. What I'm really doing is practicing. Going from extreem to another to learn what does what and thats why I went with f/32. I wanted to get the whole car in focus if I could.

Thanks.


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## SweetBlueButterfly (Apr 15, 2007)

Gary, I very recently started taking photos with my D-SLR. Initially I was in auto-mode. I then moved to the AV setting instead of full Manual. I don't think I will ever be that good. AV lets you set your f-stop and determins the shutter speed for you. You still need to determine your ISO depending on the lighting. Also check your white balance setting. Initially I had mine set to AWB then discovered there are other settings more suitable to the light. I'm just a beginner, but these are the first things I learned. Also, someone told me that you should double your shutter speed depending on your focal length. I tried this with a few shots but focus more on my AV abilities. I'm still learning. Practice, practice, practice!


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## RustyBrown (May 29, 2004)

_What I ment by thin is, the colors just didnt pop out at me. I guess I could change that with the pc. What I'm really doing is practicing. Going from extreem to another to learn what does what and thats why I went with f/32. I wanted to get the whole car in focus if I could._

Ah yes - pop.

I think the issues you're having are due to several reasons.

1) base on your shutter speeds there wasn't a flash used. Interior lights are very soft due to the bulb coatings. While it helps reduce shadows, it's light tend to be a little flat - especially at low intensities.

2) contrast and saturation - most slrs today have preset menus that allow you to adjust specific parameters of you your camera's internal software processes it's jpgs. You can boost contrast and saturation here...but i recommend leaving it alone for now. The reason for this is that these look very typical to me for interior shots. If after shooting 10 frames you feel you need a boost then make some adjustments - especially if you are doing miimal post processing.

3) white balance - I strongly recommend using auto white balance for now. The reason is that you have enough other variable to worry about. Most people her have had shot ruined because they deviated from AWB and then forgot to change back when the light sources changed. Though sometimes I change - I primarily shoot with AWB and then I adjust it in RAW. This allows me to start with the cameras reading and make small adjustments as I see fit.

To summarize I think a cleaner/whiter light would help the image, you can do some things to help it in your camera and the sooner you get your feet wet in post processing the better.

Don't sweat the focus issue. Takes us photonerds to even notice.


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## Gary (May 21, 2004)

Playing with the software.


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## Gary (May 21, 2004)

Arrg! It looked good untill I re-sized it. Back to the books!


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## Gary (May 21, 2004)

RustyBrown said:


> _What I ment by thin is, the colors just didnt pop out at me. I guess I could change that with the pc. What I'm really doing is practicing. Going from extreem to another to learn what does what and thats why I went with f/32. I wanted to get the whole car in focus if I could._
> 
> Ah yes - pop.
> 
> ...


I tried using flash and it just blew everything out no matter what settings I used. I used a light box with two 3000k tungsten lights and moved them just about everywhere. Close, far, backlight etc.

Most people seem to think the WB was off and to be honest, I hadnt played with WB much and really dont know what it does. Next time I set up I will try a bunch of different settings. One of the books I'm reading, the auther likes to allmost allways set his WB to cloudy x2 to soften, or as he says to warm the colors. That looks flat to me. With shooting macro with all these color anodized parts on the RC car, I want it to BANG in the viewers face. Its all about the bling! 

I'm starting to think this Sigma lens isnt very good, at least not what I paid for it.


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## RustyBrown (May 29, 2004)

*Looking better...*

White balance is giving me fits...


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## Gary (May 21, 2004)

Where did I go wrong with the WB? Too bright?


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## RustyBrown (May 29, 2004)

*Nope*



Gary said:


> Where did I go wrong with the WB? Too bright?


White balance is how the camera responds to different colors of light. Cloudy days create a blue cast, interior lighting yellow etc. I think the bling in your shot probbly caused the camera to over compensate.


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