fast glass question

[kellylindseyphotography]

I've been looking at my next investment which will be a new lens, probably the 2.8 one. I have some questions that have probably been asked a zillion times but for the life of me can't find what I need to know while doing a search on it...

2.8 and 1.8 are wonderful if your shooting macro and low light.. but how often do you REALLY go that low? Especially if you are shooting a moving subject and not using a tripod? (think: toddlers) With the razor thin depth of field, will this lens be to my advantage?

If not, what lens should I go for? Right now, I just shoot with the kit lens. It goes to 3.5 but I never go that far open.

 

[Big Mike]

Actually, when shooting macro, you usually want to use a smaller aperture (higher number), in order to get a deeper DOF...because being so close will usually make it thin.

A 'fast' lens (large max aperture) is good because it allows you to get a faster shutter speed than a slower lens. So if you are shooting a fast moving subject...you probably want to freeze the movement and you need a faster shutter speed to do that.

F2.8 lenses don't usually have 'razor thin' DOF...so it's not usually a worry about getting your subject in focus. The shutter speed is usually a bigger concern, and that's where 'fast' lenses can help.

Large apertures also give you the option to have a shallow DOF. You don't have to take advantage of that, if you shoot with smaller apertures...but at least you have the option.

Lastly, a larger max aperture will let more light into the lens when you are looking through the viewfinder....so it's a brighter image and AF might work better. Actually, some cameras have special AF sensors that are only useful with F2.8 or faster lenses.

 

[JIP]

A lens being a faster lens or having a 2.8 or 1.8 max aperture has nothing to do with the aperture you are going to use. Generally the maximum aperture is going to be a measure of he overall quality of a lens. If a lens is a 2.8 lens the glass is going to be larger and usually of a better quality and it will be made to more exacting standards and to boot all the other things the other people mentioned will be there to.

 

[kellylindseyphotography]

Thank you both very much, you answered my question exactly!

 

[That One Guy]

a good lens that is very sharp, great in low light and an upgrade from the kit is the 50mm f1.8. while not a zoom, it is a great lens to have. honestly i don't miss the zoom function when using that lens. it sells for around $85 i think.

 

[That One Guy]

one more thing. after you use that lens^^, next stop is the L series and believe me once you use an L you won't want anything else.

 

[ukreal1]

I love my 50mm 1.8, I couldn't afford the extra $200 for the 1.4 but I am fie with mine, ust did a model shoot the other day and very happy with the results...