question about aperature

jdphotos · Mar 6, 2011

I am new at photography but have always had a passion for it!!! last year my husband bought me a Sony A330 which i am really enjoying.:thumbup: I have been reading a lot lately and try to learn to use more of my functions on my camera. So right now i am trying to master aperture because i love when pictures are focused on the subject and the background is out of focus. But i have been trying in aperture priority and trying the same picture at different f stops and when i look at them on the camera and when i load them on to my computer everything is still in focus. I don't get it.

Also second question i have changed my setting to RAW and jpeg but when i load them on to my computer each picture is like 2 files with the same number but one just shows a box with the letters ARW not sure why it is doing this either:meh:

If anyone had any advice it would be appriciated.

JD

Big Mike · Mar 7, 2011

Welcome to the forum.

What you are trying to achieve, is a shallow Depth of Field (DOF). Yes, we do use the lens aperture to control DOF, but it is also affected by the focal length of the lens and the distance to the subject. The longer the lens, the shallower the DOF and the closer you are to the subject, the shallower the DOF. And of course, the larger the aperture (lower F number), the shallower the DOF.

You knowing that a larger aperture can give you a shallower DOF, you need to consider your lens. Most 'kit' lenses don't have a large maximum aperture (F3.5 to F5.6)...so getting that shallow DOF that you want, may not be easy. To really get a shallow DOF, most photographers use lenses with a much larger maximum aperture...F1.8. F1.4 or even F1.2.

http://www.bhphotovideo.com/c/product/622190-REG/Sony_SAL50F18_SAL_50F18_50mm_f_1_8_DT.html

Studio7Four · Mar 7, 2011

Mike got the aperture part of your question so I'll take the RAW. I also shoot in RAW and jpeg. Your camera is recording each image (each filename) in both formats. Jpeg is a universal format, so whatever you are using to browse the files on your computer recognizes it and will display the thumbnail. RAW just means that it is uncompressed - each camera manufacturer has a proprietary means for handling that data. That is, your Sony will produce a different file than would a Canon or Nikon. As such, your browser/explorer window does not necessarily know how to handle that data, so it just displays the box (I believe ARW is how Sony labels their RAW format - Canon's is CR2, for example). Your camera should have come with software which you can load which a) will allow you to see the RAW files using that software and b) likely will download a plugin for your computer which will let the RAW images be seen in your browser. Additionally, many editing software programs will have the proper plugins to display your RAW images.

KmH · Mar 7, 2011

Actually, the longer the focal length of the lens, if the subject scale in the image frame is the same, so is the DOF.

What the longer focal length gives us is background compression. Perspective compression make the background appear closer to the subject. If that background is also out of focus....

Eye Shutter 2 Think: Photography Lesson 3 In the examples, notice the distance from the camera to the subject (DTS) changes to keep the same subject scale in the image frame.

Derrel · Mar 7, 2011

It is aperture that you are working with; the word has only one a in it. That taken care of, you do not mention what lens or lenses you are using, but I will assume it is the 18-55mm kit zoom lens. With that lens, and the sensor size in the Sony you own, depth of field is reasonably deep at most apertures found on that lens. Shallow depth of field work is easier to do with longer lens focal lengths, and at wider lens apertures, like f/1.8 or f/2 or even f/2.8. So....do what you can!

PhillyPhoton · Mar 7, 2011

I thought this was helpful.

Depth of Field - AdoramaTV from Adorama Learning Center

jdphotos · Mar 8, 2011

First of all :blushing: Thanks for catching my spelling mistake!

The 2 lenes that i have are a 55-200 mm with a maximum aperture of F4 - 5.6 and my kit lens which is 18 - 55 mm aperture 3.5 -5.6

The thing with the DOF is that i have achieved it lots of times when i was just in auto mode, but i am trying to take more control of my photos so i am trying to use the different functions and learn how to get the affects i want when i want. So your advice is very helpful and i will check out the suggested sites mentioned above and i will try again to take control of my DOF! And thank you for the RAW info!!! I will have to look for the software that came with my camera and get things figured out! also i just got photoshop CS5 maybe that will display my RAW images? Also should i just be shooting in RAW mode as opposed to RAW & jpeg???
and thank you for the link to the 18 - 50 mm lens.... it's a really good price point i may have to have a look into that! !

cidrmakr · Mar 8, 2011

When you shoot in raw mode, the image you see on the back of your camera is a jpg that the camera also makes (not raw + jpg, just raw) that is embedded in the raw file. The look of it is affected by the "creative style settings" but the raw file is not. Since you are using cs5 - and I assume bridge that comes with it - when you upload from the camera you have a choice of quality in bridge to view but it is usually the jpg that was embedded in the raw file - the same one you saw on your camera. Only reason for raw + jpg is if you need quick jpgs to send to a client. Your raw file will load from bridge into acr for adjustment then on to ps. After adjusting in acr the original jpg will change to reflect those changes. As to depth of field, set your lens to the widest aperture and shoot a wall of something (curtains, blinds, jars, etc.) at a 45 degree angle. Since you can measure the distance of what you shoot, when you see the shot in your computer (at 100% in acr) you can get a good idea of what depth of field your equipment will give you.

Bill Haynes · Mar 8, 2011

I use a Sony a33. Before I switched to full manual, I used the auto+ mode, and set the display to show the shutter speed, aperture, and ISO setting of the photo. When I took a photo, I would examine the information on the camera and try to replicate it in manual mode. I continued this until I started to get a feel for how the different settings on the camera affected the photo. It also allowed me to gain a better understanding of how to access all of the functions on my camera. I just got into photography about a month ago, so I know it can be confusing at first.