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some basic questions and advice!

Travel Forums Travel Photography some basic questions and advice!

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1. Posted by jaxstar84 (Respected Member 415 posts) 7y

hey there!

after a bit of price comparison and checking around on the net, im looking at a couple of DSLRs to buy in the next few weeks... however, im still unsure of a few technical things, which i hope you guys can help with!

whats the difference, or pros/cons of a 24-70mm lens, rather than the standard 18-55mm? is one better than the other?

there are some sites which say the lens is AF18-50mmDC lens...
AF= autofocus??
DC= ??

and when then mention f3.5-5.6 UC ASP what does that mean? im looking for the asnwers myself of course, but atm im getting a bit lost in photographers language lol

any help would be appreciated! im finding all this while searching a pentax K200D with a sigma lens... if anyone has a ny advice on this one id love to hear it!

am also looking at the nikon D40 as that seems to be the way to go for cheaper SLRs...

[ Edit: Edited on Nov 22, 2008, at 10:29 PM by jaxstar84 ]

2. Posted by Sander (Moderator 4811 posts) 7y

The millimeter numbers in lenses tell you how wide the lens goes (first number) and how long it goes (second number). (If there's only one number, it's a "prime" lens, rather than a "zoom" lens. This usually means you get much higher optical quality, but loose the versatility of being able to take different kinds of photos with the same lens.)
18mm is wide-angle. Good for landscapes; you can get much more in the frame than with your old point 'n shoot (which, depending on your old p&s, would go about as far as that 24mm will do).
55mm is good for portraits, but not really powerful zoom. 70mm zooms in a bit more, but you'll probably still feel it to be limiting. (In p&s terms, they're 2.3x zoom and 3x zoom.)

(Explanation you can skip: 1x zoom on traditional camera is at 35mm. Digital SLRs have a smaller sensor, so there's a "crop factor" of 1.5/1.6. A 35mm lens on a regular camera is 35mm, but on a DSLR it appears to have a built-in 1.5 'zoom', so gives an equivalent image to what would need a 53mm on a regular camera. So you can determine zoom by taking the second mm value, multiplying it by 1.5, and dividing that by 35. (e.g. 70x1.5=105, 105/35=3))

Things are completely different for Olympus again due to them using a completely different system which I won't go into for now.


The f3.5-5.6 tell you the range of the maximum aperture from the widest setting of the lens to the longest setting. The lower the numbers the better, for it means the lens lets is more light (letting you take photos in darker circumstances), and a narrower "depth of field" (which is often found pleasing, especially in portrait photography). (However, lower (or constant) is also more expensive in most cases.)


Beyond the millimeter numbers and the aperture, every lens producer has its own terms for the same concepts.
There's vibration reduction (moves the lens to counter-act the shaking of your hand; allows you to take sharp photos in much less light; it's the difference between being able to do so at 1/50th of a second, or 1/8th of a second). Nikon calls this VR. Canon calls it IS (image stabilization). Sigma calls it OS (Optical Stabilizer).
There's also lenses which are designed for the smaller sensors of (most, excepting new high-end "full-frame") DSLRs. These are smaller and weigh less, but wouldn't work on old style camera (nor on the newest high-end DSLRs). Nikon calls this DX. Canon calls it EF-S. Sigma calls it DC.
I'd list more, but I need to run now. Hope this helps clarify some things, though! :)

[ Edit: Edited on Nov 23, 2008, at 3:29 AM by Sander ]

3. Posted by jaxstar84 (Respected Member 415 posts) 7y

SANDER! bedankt :)

but shit thats alot to take in lol ill have a good read and get back to you!

4. Posted by jaxstar84 (Respected Member 415 posts) 7y

ok... so an 18mm-55mm lens is better than a 24-70? but the first number shows how wide the lens goes, isnt it better than it goes 24mm rather than 18? thats bigger...?

and with the f numbers, you say the lower the better, than whats the best? is 3.5-5.6 good or just average?

5. Posted by Hien (Moderator 3906 posts) 7y

The 18-55 mm is the range the lens can see (focal length). The lower end (18 mm) represents the widest (landscape) view it can see. As the value increases, the view gets narrower, which means you are zooming into the view (right up to 55 mm). So you get a wider view as the value gets smaller and smaller, and the number increases as you zoom into the view for a closer look.

So to compare the two lenses, 18-55 mm and 24-70 mm, both have their own strength and weakness. The first lens (18-55) can see a wider angle compared to the second one. But the second lens can zoom in farther than the first.


About the f3.5-5.6, let's say it's for the 18-55 mm lens. The lowest value (3.5) is maximum aperture you can get when viewing on the widest angle (18 mm), while the highest value (5.6) is the maximum aperture you can get when the lens is zoomed to the maximum (55 mm). And yes, the lower the f value, better it is because the aperture is bigger.

An aperture of f3.5-5.6 is not a very good one -- it's just fine. The aperture of a professional lens (meaning expensive!) is usually in the range of f1.x-2.x.

6. Posted by Sander (Moderator 4811 posts) 7y

There's a lot of additional factors which determine real lens quality, mostly in the realm of how many aspherical elements are used, what types of coatings they've received, etc. Mostly, since you're dealing with entry-level cameras and lenses, I wouldn't even start trying to grok it all. Basic rule of thumb is: price/quality ratio is constant. The more you pay for the lens, the better it is.
The only things you realistically will want to look at are how wide a view you want the lens to cover (lower first number is wider, thus better), how much zoom you want (higher second number is longer, thus better), if you want vibration reduction with it (answer: yes, but is it worth the extra cost?), and how much of the above you think is worth getting, given that "better" in all three ways will go together with the lens getting larger and/or heavier and/or more expensive (and usually all three).

Most entry-level cameras come with a default "kit-lens". Nikon kit-lenses have a reputation of being very good for their price-point, Canon's used to be really crappy, but are pretty decent nowadays from what I've heard, and I have no idea about Pentax.
Third-party lenses (e.g. not the same brand as the camera itself is; Sigma, Tamron, etc) are hit and miss; some models are really good for a significantly lower price than Nikon/Canon's equivalents, some aren't worth getting. For me that means (together with the lack of extensive reviews of third-party lenses) that I stick to just Nikon lenses, but if money is an issue, you might want to take the gamble anyway.

Personally I'm a landscape shooter, and I couldn't conceive of starting at 24mm. 18mm is a must for me. (Actually I have a dedicated 12-24mm wide-angle lens; superb quality, but expensive.) 55mm is very limiting, too, but I could probably live with it. (I have an 18-200mm lens for the ultimate in versatility while travelling, but that's pretty costly, pretty large, and not all that good; still, incredibly useful.)
On the Nikon end of things, I know there's a recently introduced 18-105 VR lens, which a good camera store should be able to bundle with a D40 or D60 for about €150-€200 (? wild guess, but order of magnitude should be right) more than the default 18-55. That'd probably be my ideal middle-of-the-road starter lens; enough zoom to be useful, VR for low-light, yet not too heavy or too expensive. (I don't know how it holds up optically, though. My usual sources for Nikon lens reviews haven't looked at it yet.)
(Undoubtedly there'll be equivalent lenses from the other manufacturers, but since I'm a Nikon shooter myself, I don't know about them.)


Entry-level lenses are about the worst you can get. f3.5-5.6 is really bad compared to almost all other lenses. However, it's pretty standard on kit-lenses, and generally good enough. Since this is a first lens, I wouldn't worry about it. You're not yet going to spend $800+ on a lens yet anyway. (Also, when we say something is bad in DSLR land, we're only comparing to other DSLRs and lenses. The crappiest cheapo $100 lens outperforms anything found on a point & shoot camera costing less than $500, and on most p&s above that price-point, too.)

And of course, since the lenses are separate from the camera, you can just start with the cheapest one available and upgrade later (or buy additional lenses next to it) once you've learned about how you use the camera and what the biggest limiting factor of your current lens is.

[ Edit: Edited on Nov 23, 2008, at 3:16 PM by Sander ]

7. Posted by jaxstar84 (Respected Member 415 posts) 7y

thanks heaps you 2! its really cleared alot up for me... everything im looking at now makes a bit more sense, now that its been explained in a way i understand...

im not likely to get another lens yet, i just wanna learn the basics of how to use the cam n then upgrade wheni have the money and the knowledge. im gonna go for the D40 cos of the reviews ive read on it, it suits me moneywise (i might have more money to spend but we'll look at that later!) and from what ive read it seems to be a good body to start building on. the nikons seem to be a good range and if i start with a nikon, get a better lens later, i can get a better body further down the track. a decent body with a crappy lens to start is prolly better than a crappy body and a good lens?

8. Posted by Sander (Moderator 4811 posts) 7y

Quoting jaxstar84

im gonna go for the D40 cos of the reviews ive read on it, it suits me moneywise (i might have more money to spend but we'll look at that later!) and from what ive read it seems to be a good body to start building on. the nikons seem to be a good range and if i start with a nikon, get a better lens later, i can get a better body further down the track. a decent body with a crappy lens to start is prolly better than a crappy body and a good lens?

It differs; both lens and body can be the limiting factor. General wisdom is that investing in good lenses is better than investing in good bodies, though, and so most people prefer a good lens on a not-so-good body than the other way 'round. (Lenses have a much slower upgrade cycle than bodies, and a good lens could last you several decades, while advances in sensor technology go so swiftly that bodies can feel outdated barely a year after they're introduced.)

As long as you're not going to print larger than A4 size, and don't expect miracles in dark indoor places, the D40 isn't actually a "crappy" body, though. There's things it can't do, but for 90+% of the photography you'll want to engage in, it will take absolutely excellent photographs. Still, it's definitely the most paired down body out there, and lack of dedicated buttons for a lot of functionality might in the long-run be more limiting than its sensor, which would make upgrading the body a likely prospect.

Anyway, good choice on the D40. Enjoy it! :)

9. Posted by jaxstar84 (Respected Member 415 posts) 7y

ok well i had considered, if i had enough money, to go for a D60 instead of a D40, but im thinking now that i might go the D40 and see if i can scam a better lens.. i cant afford to get a D60 n try n get a better lens, so it looks to me like the baby cam is the winner!

10. Posted by jaxstar84 (Respected Member 415 posts) 7y

i think ive found a good deal on the net, but im not sure! its thru a reputable chain camera shop...

but what i found is this....

Nikon D60 with 18-55mm VR, and 55-200mm twin lens kit, with a double warranty, extra battery and a DSLR bag for $1099AUD (€550)

OR

Nikon D80 with 18-135mm lens with the same extras (bag and battery) for $1199AUD (€600)

for that price... im thinking of getting the D60... im assuming the lens WONT be a nikon, rather a kit brand, but for that price, it seems like a pretty good buy for what you get??

am i missing something!?