Glassifications

Zoom Raider

Since I'm new to the world of photography, and slowly learning...what are the "need to knows" about the f/#'s (f/3.5) and mm's in a lens? I get a feeling we're suppose balance the f#'s with the mm's. Sort'a like fuel and air mixture. Right now, I have a Quantaray with f/1:3.5-5.6 and 28-90mm. For some reason, I thought it was just a f/2.8. Dunno why I thought that. Maybe`cos of the 28mm.

So in the next few weeks, I'm gonna buy a another lens, but does it matter what the f/#'s are with the mm's? The lens I'm looking at that I may buy in June is a Quantaray with f/1:4.0-5.6 and 70-300mm's. I'm just not sure at all what these focus ratios are all about.

Today, I got my pics developed. To me, my Nikon N75 seems to do quite a bit better than regular digital cameras. I have no idea what to expect the difference to be if I did have a DSLR compared to my SLR. I guess the time, and money and batteries saved is about all,`cos I'm serious...these pics I have are very sharp and vivid. Looks as clear as 6 to 8mp's to me.:):

Some of my shots were kind'a wasted though,`cos I took 2 that I did not mean to take. The camera must have a hair trigger for a shutter button. A few others were a tad blurry,`cos I'm not sure yet how to set all these controls and features. I did take a picture of the moon that was clear, but with 90mm's, it was just a bit smaller than how my eyes could see it. They say if it's set at 50mm's, that's equal to our eyes, but with Nikon, I'm noticing that at 90mm's, it's still barely the same as my eyes.

But anyway, what do I need to know about the focus ratios?

Thanks!:):

~ZR~

wxwax

Zoom, rather than explain it, here are a couple of links for you to read.

http://www.peachpit.com/articles/article.asp?p=30319&seqNum=2&rl=1
http://www.uscoles.com/fstop.htm

To be brief, the f-stop measures how wide open the lens aperature gets. On some zoom lenses, that maximum aperature size changes as you zoom in.

Lucky Hack

Without writing a book here are some terms I would "Google" and read up on for starters...

Focal Length
Aperture
Shutter speed
Exposure
Depth of field

if you get wierd search results add the word "camera" to these terms and that'll help hone in on some good info...

or you can ask questions in the "how to-forum"

http://www.dgrin.com/forumdisplay.php?f=8

hoping this message finds you well -Ian

Steve Cavigliano

ZR,

Sid and Lucky have given you some great info to go study. Please don't think they were trying to direct you to internet sites rathere than answering your questions. Once you read what the sites they linked you to have to say, you'll understand that these things you are talking about are the essence of photography.
Explaining them would take pages and pages of text.

Please do yourself a favor and read as much as you can about these subjects BEFORE you purchase any lenses or cameras.

Here's another great site that will make more sense to you if you have read up a bit first.


Good luck,
Steve

pathfinder

Steve Cavigliano wrote:

ZR,

Sid and Lucky have given you some great info to go study. Please don't think they were trying to direct you to internet sites rathere than answering your questions. Once you read what the sites they linked you to have to say, you'll understand that these things you are talking about are the essence of photography.
Explaining them would take pages and pages of text.

Please do yourself a favor and read as much as you can about these subjects BEFORE you purchase any lenses or cameras.

Here's another great site that will make more sense to you if you have read up a bit first.


Good luck,
Steve

Like Steve said - Understanding aperature and focal length are fundamental concepts in photography.

Wikipedia has a great link about Photography and aperature and focal lengths here http://en.wikipedia.org/wiki/Photography
They do a far better job of explaining the basic concepts than I would.
:

Mike Lane

I'm going to be the brave one to give a simple answer based on experience with my lens. The faster the better. That is to say the lower the f number the better. The fastest you can get in a zoom lens is f/2.8 I think and I've seen down to f/1 in prime (non zoom) lenses. The advantages are numerous. Even if you have an IS lens, if it isn't all that fast, you could be stuck with motion blur in dark settings even if you have the ISO (and the noise) cranked up. The larger the aperature can go, generally the sharper the image as the aperature comes down to a more standard range. You'll get crazy small depth of field at f/1.4 on close in subjects which can be fun (it can also be annoying). In moderate light situations (under a shadow on an overcast day, at a special dinner dance in thailand - ARGH!) a lens that's f/4 or f/3.5 will give you soft pictures unless you want to lug around a tripod everywhere you go.

Of course there are downsides too. The faster the lens, the more shekels you'll have to dish out for it. It'll probably weigh a lot more too. If it's a canon lens, it'll probably be white and you'll have all kinds of photography buffs coming up to you to admire your lens (which could be a distraction unless you have business cards).

Anyhow, that's what I think.