More Focus

[theonlysteviet]

Hi All,

Quick question. I have gotten to the point were I always use manual now. I took some pictures of my brother-inlaw and his wife with their new baby. When I take the pictures and put them on my screen, I see issues that you cannot see when looking at the LCD on the camera when reviewing the pictures.

The main issue is, I can get the mum and dad in focus, but the baby is out. I know with auto focus, It will use multiple focus points, but manual is using just one in the center (all though I can move it around) and obviously adjust the focus using the ring on the lense. Am I doing this right? Is Fstop something I need to take into consideration? I am essentially self learning and hitting bumps along the way (which is a good thing).

I am using a D7000. The lense escapes me. I will update the thread soon. I am guessing that lenses with smaller F/ numbers will provide this feature?

I have some more pictures to take on Saturday so would really appreciate your responses

Steve

 

[gsgary]

You need to be shooting with minimum of F5.6 which is a problem if you are shooting indoors without extra lighting

 

[theonlysteviet]

So I have just watched this : - which generally explains that I need a bigger F number. I know for a fact I was shooting with the lowest setting for Light reasons. Even though I had a flash and could of bumped up the ISO. Is this all sounding right to you guys? If so, GREAT!?

 

[theonlysteviet]

Thanks GSGary

 

[Big Mike]

The main issue is, I can get the mum and dad in focus, but the baby is out. I know with auto focus, It will use multiple focus points, but manual is using just one in the center (all though I can move it around) and obviously adjust the focus using the ring on the lense. Am I doing this right? Is Fstop something I need to take into consideration? I am essentially self learning and hitting bumps along the way (which is a good thing).

Focus is the result of the physical position of the lens elements. The lens can only be focused to one specific distance. It doesn't matter if you use manual or auto focus, it doesn't matter if you use one or multiple focus points. The camera can only focus to one distance.

As you have have recently learned, your problem is with 'Depth of Field'. That is the distance in front of, and behind, the point of focus...that will also be in focus. There are a few separate factors that will determine the DOF, but the most important thing to be aware of, is that the aperture (F stop) that you choose, will greatly influence what your DOF will be.

 

[KmH]

I know with auto focus, It will use multiple focus points,

Steve

It will select from several focus points, but in the end it can only use one of them.

In manual mode you can also select any of the 39 focus points the D7000 has. You are not restricted to using just the center focus point.
Here is some info about D7000 focus settings options - http://www.pixelfinesse.com/_docs/D7000_AF_Explained.pdf

As alluded to, your issue is really depth-of-field (DoF), or more accurately, your inability to control the DoF effectively.
DoF is one of the more difficult photography concepts to understand well.

DoF is influenced by a variety of interlocking variables, like lens focal length, point of focus distance, lens aperture. Image sensor size plays a part as does.

As can be seen in the illustrations Mike has posted, DoF is a zone of acceptably sharp focus that extends in front of and behind the point of focus. The depth of that zone can be controlled by the photographer by choice of lens focal length, point of focus distance, the lens aperture used, how far from the background the subject is placed, and which camera (image sensor size) is used.

 

[theonlysteviet]

That is certainly a lot to take in. Thank you all for your time. Is it just a case of memorizing all the aperture and focal length results?
I had my subjects stand a way from the wall because I did generally want it blured in the background.

 

[weepete]

No, you can get some very useful DOF calculator apps for smartphones if you have one, you can use an online calculator or just review your image and use the zoom function to see what kind of DOF you are getting. Some cameras have a DOF preview button but personally I don't know how to use it!

 

[Benco]

That is certainly a lot to take in. Thank you all for your time. Is it just a case of memorizing all the aperture and focal length results?
I had my subjects stand a way from the wall because I did generally want it blured in the background.

You can use these to calculate DOF:

Expoaperture 2 Depth-Of-Field Guide 2 Disc Kit (Metric)

 

[Big Mike]

That is certainly a lot to take in. Thank you all for your time. Is it just a case of memorizing all the aperture and focal length results?

As mentioned, there are on-line calculators and apps for your smartphone etc. But really, after you understand the principles and you practice it for a while...you should be able to estimate what aperture you need.

And of course, you can zoom into the photos to see what is in focus or not, then adjust and shoot again if you need to.

 

[KmH]

That's all pretty simple compared to using strobed lighting (flash). Front shutter curtain sync, rear shutter curtain sync, sync speeds, flash unit re-cycle times, shutter speed controls the ambient light exposure, lens aperture controls the strobed light exposure, lighting ratios, lighting styles, etc.

 

[vintagesnaps]

Steve it sounds like you're fairly new to using manual settings (and I apologize if I'm mistaken and that's not the case). Maybe it would help before Saturday if you take some shots of an object some distance from a background so you can see how the depth of field changes and how the background would look at different aperture settings.

The f stop numbers are actually fractions, so the larger the number the smaller the aperture - f8 would mean the aperture blades leave an opening 1/8 of the focal length (f16 is 1/16 the length, f4 is 1/4 the length, etc.) (If nothing else, if it might help you could try looking into the lens and watch what the blades do as you change the aperture.) To have a background that's out of focus use a larger aperture setting.

I focus manually as you mentioned by turning the focus ring (I don't use focus points). I usually turn it til the subject looks in focus, then keep turning slightly til it starts to look out of focus, then turn back and forth til I see that the subject is sharply in focus. I think it just takes practice (because after years of using manual settings it's second nature to me). If I'm having trouble getting focused sometimes I try to find an edge or a line to focus on then reframe the shot and double check my focus, or sometimes look away for a moment then look back thru the viewfinder/at the viewscreen and double check the focus. I usually focus on what's closest to me and the camera, and set the aperture to have enough depth of field to have the entire subject in focus.

If you're indoors in lower light you might need a higher ISO so you can keep the shutter speed fast enough to keep the photo sharp too. Good luck this weekend. Sharon

 

[bruceco12]

That is certainly a lot to take in. Thank you all for your time. Is it just a case of memorizing all the aperture and focal length results?

As mentioned, there are on-line calculators and apps for your smartphone etc. But really, after you understand the principles and you practice it for a while...you should be able to estimate what aperture you need.

And of course, you can zoom into the photos to see what is in focus or not, then adjust and shoot again if you need to.

Very well said. I also experienced this problem before and one of my friends, who is a professional photographer taught me how to do it right. But of course, I didn't perfect it in the beginning. I did lot of practice before I perfect calculating the focus on my shots.

 

[Joves]

That is certainly a lot to take in. Thank you all for your time. Is it just a case of memorizing all the aperture and focal length results?
I had my subjects stand a way from the wall because I did generally want it blured in the background.

At first it is a case of memorizing, which seems daunting. The biggest thing is to practice, and experiment with it, by varying your aperture, your distance, and a subjects distance from backgrounds. After all it is digital, you can set something up and play with it, this is the best way to learn by doing it. But once you do it for a while you do not even think about it at all, you then think do I want this effect, or this one?

 

[bsinmich]

A lot of us oldtimers used the DOF scale that was on all of our lenses. I still use it a lot when shooting in less than long distance shots. That is one of the reasons I like focus scales on all of my lenses.