I'm a bit confused.

[Dodge]

Heres a few newbie questions for you guys....

I have a 70-300 4.5-5.6 lens. I've noticed that a comparable quality 70-300 3.5 lens is a lot more expensive, roughly twice the price.

Why is this and what benefits are there to the 3.5 to warrant the higher price? I can't help feeling a dumbass for not knowing, but it's just not registering with me Also, whilst I think about it, what further advantages are there to a 300 2.8 prime?

Secondly, I noticed when buying my 50mm prime, that an f1.4 was considered better than a 1.7 for example........why is this exactly? I got the 1.4 but would I have seen a vast difference if I took the same pic with both lenses?

I can't help feeling I should know this stuff already but it's been bugging me for awhile and I don't seem to have quite got my head around it. I guess it may be more obvious if I could compare lenses but my only experience is with the ones I actually own, so nothing to compare to.

[Bluenoser]

3.5 vs 4.5 = another full stop you can open your aperture. This in turns = better ability to shoot in low light. Not saying you can't shoot in low light with 4.5, just that you might have to use a flash/lighting, up the ISO, or other solutions.

Basically, the lower the Ap #, the more open you can get the AP and the more light you can let in.

The more light you can let, the faster shutter speed you can use.

[RLucas]

Hey Roger. Not stupid at all. In addition to what Bluenoser was saying, I am assuming the 3.5 you mention is a constant aperture zoom ( It stays at 3.5 all the way through the zoom range.) . They are way more expensive to make, hence the higher price.

Next, I don't know what kind of gear you are shooting, but with the Nikon 50mm, the 1.4 is supposed to be sharper, with better IQ, and color. Plus it is a heavier build. I have never shot with one to compare to my 1.8, so I am just taking people's word for it.
Hope this helps!
Luke

[gturner]

Wiki has a good explanation:
Aperture - Wikipedia, the free encyclopedia

It is really important to understand this part of how your camera works.


It fits in with this CRITICAL part of the game:
http://digital-photography-school.co...al-photography

[OsmosisStudios]

Do you have links to both items? There could be other issues at hand.

[Jim Bryant]

lower the fstop..the better. Lets in more light, give you a more shallow depth of field.

[tasmo2]

I am still new as well, so I could be wrong and if I am I know someone will correct me But....

Originally Posted by Dodge

Heres a few newbie questions for you guys....

I have a 70-300 4.5-5.6 lens. I've noticed that a comparable quality 70-300 3.5 lens is a lot more expensive, roughly twice the price.

Why is this and what benefits are there to the 3.5 to warrant the higher price? I can't help feeling a dumbass for not knowing, but it's just not registering with me Also, whilst I think about it, what further advantages are there to a 300 2.8 prime?

Secondly, I noticed when buying my 50mm prime, that an f1.4 was considered better than a 1.7 for example........why is this exactly? I got the 1.4 but would I have seen a vast difference if I took the same pic with both lenses?

I can't help feeling I should know this stuff already but it's been bugging me for awhile and I don't seem to have quite got my head around it. I guess it may be more obvious if I could compare lenses but my only experience is with the ones I actually own, so nothing to compare to.

Your lens will have an ap of 5.6 zoomed out and no larger. your 4.5 will be at 70mm, once you start zooming out you will immediately start loosing f stops. So actually your lens zoomed at 250 or 300 would be 2 f stops different. Make sense? So basically, the more expensive one has a wider ap which in turn makes it faster glass.

I only have the 1.8 50 prime, so I can't say anything about the difference between those. I would think the 1.4 would be a tad better indoors, maybe not a huge difference outdoors. But that is just me assuming.

And remember, the only stupid question is the one you didn't ask! (and sometimes the one that has been asked 87,000 times and you didn't search before you asked.. LOL But I think we are all guilty of that one at one point!)

[Solarian]

Not a stupid question at all. The differences in those lenses are both visible and invisible. The visible one, is the maximum aperture, making the 3.5 a faster lens. You can open it up a lot more, and let in a lot more light. This will help you in darker places, as well as allow you to get really nice background blurrs if you want to.

The invisible difference is the image quality difference. Generally speaking, faster lenses are higher quality. The fact that they're faster doesn't make them higher quality, but the manufacturer assumes that people that want fast lenses are more picky about quality, so they build those to higher standards. This is not always the case, but 8/10 times it is.

[Dodge]

Thanks everyone.

That's actually completely cleared things up for me. I guess I just needed it in laymans terms to get my head around it. I suspect that the info was in there somewhere, I just needed it pointing out which was relevant and why.

The lightbulb came on and it's clicked into place after reading your replies so thanks again guys ! That's a great help.