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Photography Question 

Wendy Ellis
 

What am I doing wrong?


 
 
I am at my wits end - I just don't know what I'm doing wrong. I shot two pictures yesterday (I'm going to try to attach them to this question) - The first one is of my dad with my oldest daughter. Here are the stats: ISO 125, 1/125, f/5.0, 125mm. The second is of both of my parents with both of my daughters, stats = ISO 125, 1/125, f/4.5, 110mm.

The main difference between the two pictures is the different aperature and focal length. In the one of just my dad and daughter, my dad is blurry and my daughter is in focus. I just can't understand why this would be since the aperture on this picture is slightly smaller than on the picture of all four of them. And all four of them are in focus on that one with the bigger aperture.

I wanted the background to blur, but does it make sense that my dad would be blurry when he is sitting so close behind my daughter who is in focus? Is this a focus/depth of field problem, or is it something else? I'm SO frustrated!!! Any help that anyone can give will be so appreciated.

Thanks,
Wendy


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March 08, 2005

 

Wendy Ellis
 
 
 
Trying again to upload photos...


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March 08, 2005

 
- Gregory LaGrange

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  Neither one looks too clear. More of a motion problem.


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March 08, 2005

 

Melissa L. Zavadil
  I had some frusturating focusing problems with my canon 10D for a while. I brought it in to a local shop and had the lens cleaned up and I also checked some of the stock lenses in the shop to rule out if it was the lens or if it was me. I ended up having to have the focusing recalibrated. Just a thought never hurts to pop on a different lens. But I do have to unfortunately agree, both the pictures above look out of focus to me- motion/lens?


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March 08, 2005

 

Wendy Ellis
  You mean, motion of the camera or the subjects? The camera was mounted on a tripod and I used a shutter release to take the picture. So I thought I was eliminating camera shake. The shutter speed on both of these (I thought) was sufficient to freeze motion of the subjects.

You are right - they both have blur problems. The second one just didn't seem as bad as the first, which didn't make sense to me either (if it was an aperture problem). I'm just so frustrated because all my shots from that session came out like this! I used a canon 75-300mm telephoto lens for these. I also have a canon EF24-70mm F2.8L USM lens and I get the same blur from that lens too! But when I use the 18-55mm kit lens, my pictures come out pretty sharp. I just don't get it!


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March 08, 2005

 
- Robert Hambley

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  Greetings,

Can you try manual focusing and see if the autofocus lights say it is in focus when you eye tells you it is?

And if, when it is in focus to your eye, are the resulting pictures ok?

I would believe it is the autofocus in the camera being off if multiple lenses have the same problem. You might need what Melissa mentioned, getting it recalibrated.

Good Luck!
Robert


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March 08, 2005

 

Wendy Ellis
  Thanks everyone for your help and feedback. Sorry I'm so frustrated! I will try what you mentioned, Robert, and see what happens. I will probably also check into having the focus recalibrated - thanks Melissa. Didn't even know that was an option. I'm such a newbie.

Thanks again!


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March 08, 2005

 

Jon Close
  There is a difference in depth of field between the two pictures because all the pertinent variables are not the same.

The most important is the subject distance. The subjects in the 2nd photo are almost 1/2 the size they are in the first. You were probably 2x farther away. Depth of field increases with subject distance. The differences in focal length and aperture were very small and not a significant factor.


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March 08, 2005

 

Melissa L. Zavadil
  Jon,
Can you explain further, your statement 'the differences in focal length and aperture were very small and not a significant factor.' I am not sure I am following you.
Just curious. Thanks a lot in advance.


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March 08, 2005

 
- Gregory LaGrange

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  125mm and 110mm are close enough that any of the amplification you get from telephoto like narrow depth of field, or motion steadiness problems aren't going to be a factor going from 110mm to a slightly longer 125.


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March 08, 2005

 
- Gregory LaGrange

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  125mm and 110mm are close enough that any of the amplification you get from telephoto like narrow depth of field, or motion steadiness problems aren't going to be a factor going from 110mm to a slightly longer 125.


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March 08, 2005

 

Wendy Ellis
 
 
 
Actually, Jon, my camera as on a tripod, so my distance from the subjects was the same in both pictures. I guess I just cropped one closer than the other (oops).

The reason I thought that it maybe was a depth of field problem is because even though my daughter is not sharp in this picture, she seemed to be MORE in focus than my dad.

I'll upload one more pic so you can see what I'm talking about. Please ignore the HORRIBLE composition on it, but notice that my dad is really blurry and my daughter is much more in focus. Just initially looking at it, it seemed like it was a depth of field issue, but I don't know. Maybe I've got a couple of different things going on at the same time...


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March 08, 2005

 

Wendy Ellis
 
 
 
Okay, here's the pic I mentioned. (why can't you upload a pic in the FIRST response? Oh well, one issue at a time... heehee)


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March 08, 2005

 
- Robert Hambley

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  Greetings,

Your dad is out of focus as a result of the depth of field. You were using a zoom lens at 265mm.. The depth of field shrinks as the lens length grows. Also, the larger the aparture the smaller the depth of field. So I would try a shorter lens and a smaller aperature.

Thanks,
Robert


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March 09, 2005

 

Wendy Ellis
  So, then, is it basically impossible for me to use my telephoto and get pictures of more than one person? I'm planning on taking my daughter to the arboretum next week with all her friends to see the tulips. I was planning to use my telephoto because I thought I'd get more candid shots if I could take them from a little bit of distance instead of having the camera right in her face. But that means that all of her friends, if they are in the frame and if I'm focusing on her, will be blurry. Is that right? I'd be better off shooting with a standard zoom lens?

Thanks for your insight everyone! I'm trying to learn!


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March 09, 2005

 

Tammy L. Odell
  Hi Wendy,
Someone correct me if I am wrong, but the digital rebel does have a crop factor of 1.6x, so could that affect the outcome of the image if the shutter wasn't fast enough for a focal length of 200 instead of 125?? Like I said, that probably doesn't have anything to do with it, but thought I'd ask.
Wendy, are you sharpening any of the images in photoshop?? I was unaware inwhen I first got my rebel, that digital images needed sharpening especially around the eyes. The second photo may benifit from a bit of sharpening. I am no expert at all, but that's just my 2 cents!! Oh and I agree with Robert on the telephoto lens, I have a 70-300mm and has a very shallow depth of field, not real great for group shots!!


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March 09, 2005

 
- Robert Hambley

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  Greetings again,

First you can use a telephoto, just try using a shorter focal length on it, or use a larger f-stop.. like f8 or f11 (or larger if necessary) to get a larger depth of field. The shutter speed might then demand using a tripod or other support, monopod, etc. You could also use the auto-depth of field on the camera to try and determine the right depth of field...

Also, don't forget the depth of field preview button on your camera. It can really help before you press the shutter to find out what will be in focus.

Tammy, the 1.6 multiplication factor has to do with the sensor size and doesn't affect the the focal length, or more specifically, the 1/focal length to get the shutter speed for handheld. It just refers to an extra magnification that the smaller sensor gives. A 500mm lens becomes 800mm etc, but the 1/focal length is still 1/500 for handheld photography.

However, ask any one of the instructors here and they will say use a tripod as often as possible, as it will increase the sharpness of ever picture. It seemed like a hassle at first, but now, I don't even think of it, it is just part of taking a picture.

Good Luck!


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March 09, 2005

 

Wendy A. Blanchard
  Hi Wendy, I have had the same problems and I love my 70-300 for portraits. It is a matter of your apeture. You do need to use a larger f-stop. The background will still have blur.


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March 09, 2005

 

Wendy Ellis
  Thanks, everyone. I will definitely use a larger f-stop next time. I wasn't expecting the background to still blur so well at F8, but it did (I just spent some time experimenting). So, last question: (and this may be a dumb question), what, then, does it mean when my lens says it's a 75-300mm F4 - 5.6? And what, if anything, gets affected when I use an aperture higher than 5.6? Does it just mean I might need a tripod for those shots?

Tammy, those HAVE been sharpened in PS, believe it or not. I was SO disappointed when the shots came out as badly as they did because my Dad is in horrible health and it may have been one of my last opportunities to get pictures of him with my girls...


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March 09, 2005

 
- Robert Hambley

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  Greetings,

No dumb questions...

The F4-5.6 identifies the maximum aperature that the lens has at each end of the zoom ... for yours ..at 75mm its max is F4, at 300mm its max is F5.6. Smaller aperatures (larger F-stops) are not a problem.

Technically, lens-wise, nothing is affected by using a larger F-stop (smaller aperature), it affects the length of time the shutter must be open.

You will need a tripod when the 'rule of thumb' shutter speed is less than 1/focal length. IE.... 1/125 on a 300mm focal length shot. However, by this rule of thumb .. anything over 1/300 on the 300mm focal length should be fine handheld.

Good Luck! and hope this helps!


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March 09, 2005

 

Wendy Ellis
  It does help, Robert! Thank you so much!


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March 09, 2005

 

BetterPhoto Member
  hey Wendy, I have a big pet peve about things in foucs. So if I shoot people, I set the smallest f-stop possible and just make sure the backround is far away. Something is definitely wrong, looks like nothing is in focus. For portrait its best to have a set lens like 85mm, 105, or 135. These wide range lenses loose qaulity. I only have a 70-200mm because I shoot weddings and might not be able to get closer during a ceremony. Maybe you could manual focus on your daughter and then your father in another shot and stich them together. If not then have them on the same focusline(best bet).


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March 13, 2005

 
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