Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Canon EOS dSLR

Reply
 
Thread Tools Search this Thread
Old Sep 7, 2007, 10:11 AM   #11
Moderator
 
Join Date: Aug 2004
Posts: 8,529
Default

WilliamG wrote:
Quote:
Thank you for the replies! You're all very helpful. I'll make sure to get a good lens hood.

So, a few more questions:

1.) What is a B&W UV filter? I can make some obvious assumptions, but more info here would be good...
Quote:
B&W is a brand - they make quality filters as does Hoya
Quote:

2.) Shoot only at 50mm? As in zoom length? (I are not camera-smart).

4.) I need to read about apertures/shutter priorities since I know very little about that...

5.) Out of interest, on a point-and-shoot camera, they have things like 4.0 optical zoom. How does a 28-135 lens compare to those point-and-shoot cameras? Is there a correlation between the two at all?
Quote:
The 4x is simply a ratio of shortest focal length to longest. In dslr terms it is meaningless - a 25-75mm and a 100mm-300mm lens are all 3x zooms A 28mm prime and a 600mm prime are both 1x lenses. In both cases the lenses are completely different. In the digicam world, most digicams start at 28-35mm equiv. focallength so the 3x and 4x nomenclature is more relevant. For now, throw that concept out the window - it holds no meaning in your world.
Quote:

Thanks again for all the help. I'm hoping my books arrive today so I can understand a little more about the more technical stuff!



**EDIT**

Uh oh! We have someone saying don't get a UV filter, but get a polarizing filter. Now I'm interested in what the two do.
Quote:
This is an ongoing debate. Some people like Nick argue that you should always use a UV filter to protect the lens. Others argue that the filter offers no real protection and ANY additional piece of glass you put in front of your lens is going to cause SOME degredation of light and thus image quality. I used to be in the camp that says you should use one - but then I started using lens hoods on all my lenses which offers the protection so I don't use UV filters anymore. The one time I could see still using them is in sandy conditions to prevent blowing sand from getting on the front element and potentially scratching it.
Quote:
Also a polarizer filter is not a filter you leave on all the time - it works like polarized sunglasses - it will deepen the blues of the sky and provide contrast with clouds, but it also cuts down on reflections from glass, water etc.
JohnG is offline   Reply With Quote
Old Sep 7, 2007, 10:19 AM   #12
Member
 
Join Date: Sep 2007
Posts: 31
Default

Wow that was a lot of technical information that went fairly substantially over my head!

Thank you, though. I intend to come back to this information after some reading.

About a polarizing filter, I think I'll hold off on it for a bit, since that will take some more reading (many people don't like the Canon one, apparently). Must...read...more!

For now, I'm getting my pictures uploaded so you can tell me what you think...

Thanks again!


WilliamG is offline   Reply With Quote
Old Sep 7, 2007, 10:31 AM   #13
Member
 
Join Date: Sep 2007
Posts: 31
Default

OK here are my first pictures. Just JPEG format, and no post processing (not quite at that stage yet).














My wife actually took those last two. With my ...*cough*... expertise, I can see she's a natural!
WilliamG is offline   Reply With Quote
Old Sep 7, 2007, 12:16 PM   #14
Moderator
 
Join Date: Aug 2004
Posts: 8,529
Default

William,

Looks like you and your wife are having fun.

The only TECHNICAL thing I'd point out is that the dog moving suffers from what is called front-focus. If you look, the grass in front of the dog is more in focus than the dog itself. That happens.

But one of the things that jumps out of all the photos has to do with that difficult composition thing. All these photos pretty well have the subject in the center of the frame. Hey, it's the way most people shoot. However, the brain of a person looking at an image works a bit different. Do a search on 'rule of thirds'. This is one of the fundamental concepts of composition. It isn't a hard and fast rule but it is a guideline and it is not something intuitive - i.e. intuitively you think a subject should be at the center of the frame. In most cases, the image looks 'more right' when the subject is NOT in the center.

But don't worry - keep working at it.

I'd also like to contradict another viewpoint here. I disagree with the notion that you need to start posting photos right away and getting feedback. You're absolutely welcome to do so, but I think it can be a bit counterproductive to the learning process. I recommend taking some time to get used to the equipment and studying and practicing first. Here's why. You've posted 3 completely different types of shots here - action, portrait and macro. All of these types of photography have their nuances. And I think it's a bad idea to try and learn all these things at once.

Here's where posting on forums can be VERY beneficial: When you have a general idea about photography under your belt and you develop an interest in a certain part of photography - let's say after a month you find yourself really into those portrait shots of your dog. The great benefit of these forums is you post one of those shots and ask for feedback. You can get very specific feedback on things that affect THAT TYPE OF SHOT. So you can refine your technique in that area more. Then say your wife wants to do the macro shots - she can post a shot or two and get specific feedback on THAT TYPE OF PHOTOGRAPHY. But, it's important that you learn to walk before you learn to run.

Now there are plenty of forums on this site and others where people just like to share photos without critique - you have a favorite shot and you want to share it. Nothing wrong with that. But you don't learn from those types of forums - that's not their purpose. So, my advice is to take it a bit slow - concentrate on the basics first - asking questions for clarification. But hold off on the posting photos for critique until you're more familiar with the basic concepts. That way when we start talking about front-focus and needing shallower depth-of-field and having more contrast and applying USM (unsharp mask - a post processing term) you won't think we're speaking in Greek. Again, just my opinion. Not trying to dismiss you or anything just suggesting that posting photos for critique and feedback is like jumping into an ocean with 7 foot swells when you haven't learned how to swim yet!


JohnG is offline   Reply With Quote
Old Sep 7, 2007, 12:48 PM   #15
Member
 
Join Date: Sep 2007
Posts: 31
Default

Thank you for the reply! I'm glad to be able to say that I knew the first dog picture suffered from front-focus, and that the rule of thirds was ignored! Yay! I remember things from my film classes!

Quick questions:

1.) The macro mode was not used for any of the close-ups. I know from using my point-and-shoot SD700is Canon that macro mode was a must, since close-ups looked much clearer with it on. With the 40D, though, turning on macro mode didn't seem to change anything. Did I miss something there?

2.) What is the best way to get focus really quickly on something you can see already, but might move? e.g. my dog is lying on the grass, and I want him to run toward me so I can get a picture of it. Is there a way to get quick definitive focus on him when he's running? (i.e. to avoid the front-focus issue)

Thanks!
WilliamG is offline   Reply With Quote
Old Sep 7, 2007, 1:39 PM   #16
Member
 
Join Date: Sep 2007
Posts: 31
Default

I now have a third question!

I've been reading my EOS Camera for Dummies book, and it's full of all sorts of useful information. This part took my interest, though, as I'm trying to work out shutter speeds.

This is a quote from the book:

"There's a rule of thumb: you can handhold a camera and get a sharp picture so long as the inverse of the lens focal length is larger than the camera's shutter speed. As an example, say you're using an 85mm lens. The inverse would be 1/85. When you shoot a picture, if the shutter speed is faster than 1/85 of a second, then you should be fine."

He goes onto say that this is an approximation and that he's taken photos that break this rule.

Now, for my lens, which is a 28-135, what does this mean? Trying to get a general idea here.

Thanks again for the help. I won't be a newbie for long.
WilliamG is offline   Reply With Quote
Old Sep 7, 2007, 2:05 PM   #17
Moderator
 
Join Date: Aug 2004
Posts: 8,529
Default

WilliamG wrote:
Quote:
Quick questions:

1.) The macro mode was not used for any of the close-ups. I know from using my point-and-shoot SD700is Canon that macro mode was a must, since close-ups looked much clearer with it on. With the 40D, though, turning on macro mode didn't seem to change anything. Did I miss something there?
Quote:
I'll leave macro questions for someone else I don't do much macro.
Quote:
2.) What is the best way to get focus really quickly on something you can see already, but might move? e.g. my dog is lying on the grass, and I want him to run toward me so I can get a picture of it. Is there a way to get quick definitive focus on him when he's running? (i.e. to avoid the front-focus issue)
Quote:
The answer is the focus mode. You need to use AI-Servo focus mode - the manual will tell you how to set the focus mode. In a nutshell what happens in this mode is the camera constantly re-focuses (as long as you hold the shutter half-way or all the way). However, this won't necessarily fix the front-focus problem. The camera has to actually be focusing on the subject to start with for servo to work. So, there are two ways to help the camera do this: 1) fill the frame with your subject - i.e. the larger the subject is in the frame the more chance the camera will focus on IT and not something else. 2) if you can't do that because you don't have a long enough lens and/or your subject is small and/or too far away (like your dog running) you can improve your odds by selecting just a SINGLE focus point and not all focus points. Your manual will tell you how to select focus points. There are more details about focusing and success in action shots (my particular area of interest as a sports photographer) but the above is a good enough primer to get you going.
Quote:
Thanks!
Quote:
Now, for my lens, which is a 28-135, what does this mean? Trying to get a general idea here.
Well, this isn't as easy an answer as the other questions. In the strict sense it means if you were zoomed out all the way (at 28mm) the principle states you need at least 1/28 shutter speed to hand-hold. If you're zoomed all the way out at 135mm you need at least 1/135 to hand-hold successfully.

Now, here's where things get more complicated.

First, some would argue that since the DSLR you're using applies a 'crop factor' of 1.6 (do a search on crop factor) it makes your lens an affectively 44.8mm - 216mm. So this camp would argue you really need 1/45 at the short end to hand-hold and 1/216 at the long end to hand hold. My opinion is: this is a guideline anyway and every person is different so don't get hung up on whether it's 1/135 or 1/216 according to the rule. You need to find out what it is for YOU. Your steadiness and technique will have a big impact on it.

Second, not all lenses are the same weight. A 200mm 2.8 lens weighs a lot more than a 200mm 5.6 lens - so it's harder to hand-hold. So that affects this as well. While you may be able to hand-hold a 200mm 5.6 lens at 1/200 you may require 1/320 or 1/400 to hand-hold a 200mm 2.8 lens.

Third - your lens has Image Stabilization. It's an older generation of the technology and Canon claims it provides 2 stop advantage for hand-holding. So if you could normally hand-hold a shot at 1/200, by using IS you could hand-hold at 1/50 (1/50 is two stops of shutter speed below 1/200).








JohnG is offline   Reply With Quote
Old Sep 7, 2007, 4:32 PM   #18
Member
 
Join Date: Sep 2007
Posts: 31
Default

Thank you again for the reply. So what it really comes down to is that it doesn't matter what shutter speed you use, really, aside from the obvious effects of using the different speeds.

So would I be correct in posing this question and answer?

Q: What is the best shutter speed to take THIS picture?

A: There is no correct answer, but this general range is a good starting point.
WilliamG is offline   Reply With Quote
Old Sep 7, 2007, 7:54 PM   #19
Senior Member
 
nickphoto123's Avatar
 
Join Date: Aug 2004
Posts: 1,356
Default

WilliamG,

Seems you are ignoring my suggestions. That is not a bad move.....

HOWEVER... your posts and follow-up questions indicate you are trying to grasp at all facets of photography at the same time.

The underlying problem in your approach is that you think you are asking the 'Correct Questions' about an issue.

You have been tossed the Rule of Thirds. IGNORE IT.

If you follow my suggestion of shooting a 50mm for a month, your resulting images will reflect the world as YOU SEE IT, YOUR VISION OF THE WORLD.

Once you get a feel for your own Photographic Vision, you can then evaluate applying various 'Compositional Rules' as 'the Rule of Thirds'.

My suggestionscause you to foucus on Composition and Light.

They require your time and attention. They require you to make evaluations on each of your shots. Try it for a week, you'll like it.

P.S. : Buy a B&W UV filter and put it on your lens. Check B&H and others.

All those saying only a lens hood is all that is needed, never mention the hundreds of times they had to clean the front of their coated lens and have affected the coating on their lens. They never admit to this. An old Polish expression is "Cheap is Expensive".

Good shooting with your DSLR.

Waiting to see images of your view of the world,

Nicholas




nickphoto123 is offline   Reply With Quote
Old Sep 7, 2007, 8:03 PM   #20
Moderator
 
Join Date: Aug 2004
Posts: 8,529
Default

nickphoto123 wrote:
Quote:
All those saying only a lens hood is all that is needed, never mention the hundreds of times they had to clean the front of their coated lens and have affected the coating on their lens. They never admit to this.

hate to disagree with you Nick but if you take care of your gear there's no need to clean your lenses hundreds of times. About twice a year is good.
Quote:
Seems you are ignoring my suggestions. That is not a bad move.....
Glad you think you know more than the rest of us. Sorry the OP didn't bow down and take as gospel your advice but decided to think. Perhaps he'll see the light. Keep working at it Nick - someday you'll be as good a photographer as you think you are

JohnG is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 2:30 PM.