First post. Need criticism to learn!

[CONSTANTINE]

Well i definately feel new to this now that ive been browsing this site. If someone can tell me why the person or subject gets blurred or direct me to a link that explains it that would be great. Or any criticism in general that would be great too. Shots were taken with my 50mm 1.8

[nicolerork]

The 50mm is a great lens, did you have it on Automatic or Manual mode? It looks like you had it on Auto. The subjects are blurred because of the depth of field. For the first one, step back a little bit and focus the shot manually. On the second shot just focus it manually.

Love the second one!

[CONSTANTINE]

Thanks! I had it on automatic focusing. I figured it was because of the depth of field. How can i change that? So you suggest using the manual focus most of the time?

[ibdb]

I think the focus on #2 was ok (might have a little more of the hair than the eye) -- it's just got too shallow DOF. Just because you have an f/1.8 doesn't mean you always have to shoot at 1.8.

Try taking a series of pictures of the same thing, the same way, only moving from a shallow depth of field (f/1.8) to a much deeper DOF (f/16 or more). Compare each photo to the next to see what your lens is capable of doing.

[CONSTANTINE]

Ok so 1. use manual focus more often and 2. use an f stop thats higher. How do i know which f stop will make her face not blurry? or is it just trial and error? IBDB i will try doing what you said also

[nicolerork]

On your lens there's a switch with "AF" and "MF," move it down to the "MF" for manual focusing. I usually use manual focusing for still life and some portraits (although sometimes I don't get the depth of field that I'd like). I use auto focus for faster-paced photos such as sports, concerts/shows, traffic, etc. Try it and let me know how it goes!

Portraits are much more crisp when you focus manually (shot with a 50mm f/1.8 )

[taramcg]

I have this lens and I am new to DSLR. I find that I need to focus on the iris of the eye for contrast with AF to make it more sucessful. I can do MF, but it takes me too long (can't see too well) and with kids this is often a hard thing. I also find that this lens does much better at 2.5 - 3.2 than at 1.8. HTH!

[Darvon]

Constantine, it all depends what you want to do... but you're starting to really explore with the basics (and to me some of the most fun) of photography. Aperature (or f stop) is directly related to shutter speed and the amount of light hitting the film or sensor. A smaller aperature (higher f stop number) creates a greater depth of field, but to acheive the same lighting, you need to slow the shutter by the same number of "stops." I actually really like your second photo because of the shallow DOF. Manual or automatic focus should hopefully acheive the same quality focus, but there does seem to be a number of folks on here say their camera's autofocus is off. I've noticed mine is off sometimes... like low lighting situations. Then you may want to try manual. But most of the well-lit situations will get just as good focus especially if you focus on a "high contrast" area. Typically, too, using the central focus out of the multiple focus areas gives the best focus because it uses horizontal and vertical lines whereas others use only horizontal (or maybe that's only vertical... I don't remember).

Experiment, experiment, experiment.

[CONSTANTINE]

Thanks for the advice Darvon. Is there a link where i can read more on the aperture and how it effects my shutte speed. I thought picture 2 wasnt good because some of her face is blurry but i actually see what you mean, it doesnt look that bad.

[Darvon]

Originally Posted by CONSTANTINE

Is there a link where i can read more on the aperture and how it effects my shutter speed.

I don't have a web site off the top of my head. Shutterbug.com has lots of little tips, etc. Go to your local library and get a Basics of Photography book... just something to review some of the shutter/aperature relations. Depth of field can be used both shallow or deep. Just depends on the effect you are looking for.

[Andy_T]

Hi constantine,

welcome to the forum

The first image is simply boring, because the viewer doesn't know what it should be .

The second, on the other hand, does have potential. I like it.

Originally Posted by CONSTANTINE

Is there a link where i can read more on the aperture and how it effects my shutte speed.

It's pretty simple, actual.

With every full f-stop, you lose half of the light (because the hole through which the light hits your sensor is reduced in size).

In order to get a properly exposed image, if you lose half of the light, the shutter has to stay open twice as long. This - of course - can lead to a blurry image because of camera shake at a certain point. (1/15 s is way too slow!)

Full f-stops are 1.0 - 1.4 - 2.0 - 2.8 - 4.0 - 5.6 - 8.0 - 11.0 - 16.0 ... starting at 1.0 and multiplying it with 1.4
(which is roughly the square root of 2, as the hole through which the light comes has 2 dimensions)

So if you stop down your lens from f/1.8 to f/2.5, you will need twice the shutter speed.

Recommended Shutter speed:
The 'rule of thumb' is that you should use 1/focal length * crop factor as minimal shutter speed -> for the 50/1.8 on a 1.6x camera this translates to 1/(50*1.6) -> 1/80 second. The average person should be able to get sharp handheld images with that, if you have nerves of steel, you can do better, if you are suffering from Parkinson's disease, you'll have a hard time. Also ... if you go below 1/50, then any movement of your subject will also be visible.

So I am amazed that in your second image (1/15s shutter speed) something at all (the hair, that is) is sharp in your image. Try to increase the ISO from 400 to 800 (twice as much sensitivity to light) and further to 1600 ... your shutter speed will go to 1/60 and possibly give you better results.

The aperture (f/2.5) looks ok to me, this should give you reasonable DOF at this distance.
I normally used f/2.8 as starting point on my 50/1.8. According to my experience, you should not go much below f/2.5, as the images will not be too sharp then.
You get more DOF if you increase your distance to the subject. Other than that, select the center focal point (otherwise the camera will decide where it wants to focus, and that might not be your choice )

So my suggestion ... practice, practice, practice!.
Doesn't cost anything apart from the time you spend.
Use AV mode to select the aperture (the camera selects the corresponding speed). If you see in the viewfinder that the speed is too slow, increase the ISO and/or the aperture.

Hope that helps...

Originally Posted by nicolerork

Portraits are much more crisp when you focus manually (shot with a 50mm f/1.8 )

WOW! I really admire your eyesight .
I could not focus correctly with my 20D if my life depended on it (before I got my split prism focusing screen). It looked great in the viewfinder, but not so great in the downloaded image.
At what aperture was that image taken that you linked?

Best regards,
Andy

[BLINN]

I think that manual focus is a bad idea. your eye can not focus fast enought it the subject moves and therefore you can not compensate for it fast enough. there is a reason why slr's added autofocus. All you have to do is be aware of what your camera is focusing on, and watch the depth of feild. Try changing the AV to the next higher increament. The biger the apature value the smaller the open is that lets light in to your camera and less DOF. There all is in focus. The smaller the apature value the larger the opening that lets light into your camera and the greater the depht of field. Here is a link that might explain it better.

http://www.dofmaster.com/dofjs.html

hope this helps. cute kid

[Fred525]

Constantine...

I'm in the same boat as you and am trying hard to learn and grasp all that I can from these boards as well as practice when I can. Unfortunately, I have more time to read the boards than I do to shoot since the internet is 24/7.

Anyway here are a couple of links to pages that I've picked up from these boards. They've helped me.

http://www.camerasinteractive.com/index.php#
http://www.camerahobby.com/EBook-TOC.htm
http://www.uscoles.com/fstop.htm

Enjoy!