Comparing f/1.8 to f/2.8

[PHeller]

I'm looking at lenses, mostly low light choices.

As you may have seen in my other major post, "Making Money the Smart Way", I take many pictures of Ballroom dancing.

Low light situations, but not really really dark; just not outside in full sunlight and im trying to avoid the flash when I can.

I would go for the 50mm f1.8 or an 80mm of the same speed, but I also just noticed that there is a 28-70mm f/2.8.

How will a f/2.8 compare to a f/1.8.

Although I will still probablly pick up a prime, I wouldn't mind having a zoom lense for usability.

Anything thoughts?

Anyone have pictures comparing these two?

[cdifoto]

Honestly, in a ballroom setting, even f/1.4 and ISO1600 isn't necessarily fast enough to get a usable shutter speed. You can effectively use flash that doesn't look like flash.

[RebelRat]

The f1.8 is one full stop faster than f2.8. Your shutter speed will be a bit faster in low light at f1.8.

Using my 50 f1.4 lens to properly expose a subject here in my room.
Here are the shutter speeds I attained.

@f1.4 = 1/25 sec

@f1.8 = 1/20 sec

@f2.8 = 1/8 sec

[PHeller]

Well at these competitions there is alot more light then people would expect.

I was getting only "slightly" underexposed pictures wide open on my kit lense, which was...i think...a 5.0 or whatever the D50 came with.

Supposedly this place was darker then normal too.

I am just trying to consider more options, because im sure there will be times when i'll be wanting something with a little zoom.

[cdifoto]

Get everything then. An f/2.8 zoom for convenience and a few faster primes for speed. You really should have both anyway since you'll technically be a professional. You should also have a backup body just in case but since no one is paying you to show up then it's not such a big deal if your cam dies.

[PHeller]

alright, well then for starters, where do you get your "money tree" seeds?

[cdifoto]

alright, well then for starters, where do you get your "money tree" seeds?

www.a-job.com


If you can get away with a good 2.8 zoom then there you go. No need for a prime right now. Put back your earnings and get a prime later.

[PHeller]

The key will be determining wether or not I can get away with just a 2.8...so far, I've only done one event, but after Christmas it will pick up again.

Anyone know of a high concentration of Nikon stuff used or classifieds?

I haven't checked out Nikonians yet, i'll do that now.

[cdifoto]

The key will be determining wether or not I can get away with just a 2.8...so far, I've only done one event, but after Christmas it will pick up again.

Anyone know of a high concentration of Nikon stuff used or classifieds?

I haven't checked out Nikonians yet, i'll do that now.

www.fredmiranda.com forums is usually a good source for used. Or www.keh.com. Bought my 10D pretty cheap at keh. They also provide warranties.

Preparedness is expensive.

[PHeller]

So what do I need to know about f/2.8 lenses.

I know some limit you to wide open to only a certain focal length, others, more expensive, allow using 2.8 in the whole range.

Lots of choices though. we have 17-40mm, 17-50, 50-150, ect ect

Which is the best bang for the buck?

I dont have a zoom lense right now, just my kit, so I might be able to get away with a 50-150mm f/2.8 to fill in for the low-light lense, motorsport lense and for outdoor wildlife shots.

What do you think?

FredMiranda seems to be dominated by Canon users...I've got a Nikon.

[cdifoto]

So what do I need to know about f/2.8 lenses.

I know some limit you to wide open to only a certain focal length, others, more expensive, allow using 2.8 in the whole range.

Lots of choices though. we have 17-40mm, 17-50, 50-150, ect ect

Which is the best bang for the buck?

I dont have a zoom lense right now, just my kit, so I might be able to get away with a 50-150mm f/2.8 to fill in for the low-light lense, motorsport lense and for outdoor wildlife shots.

What do you think?

FredMiranda seems to be dominated by Canon users...I've got a Nikon.

I don't know a lick about Nikon lenses in particular (which ones are good vs bad) but I can tell you some general lens information.

The ones that limit apertures at certain focal lengths are called variable aperture. Usually you want to steer clear of those. They make shooting rather inconvenient because you can't just set your aperture and maintain your exposure while zooming in and out. You're constantly making adjustments based on your focal length unless already stopped down past the max zoom's widest aperture. They're also generally slower. On a 17-55mm variable aperture you might get, for example (random numbers off the top of my head), f/2.8 at 17mm then when you get to 25mm you can only open up to f/4, then by the time you're at 55mm you have to be at f/5.6. f/5.6 is really dark and you won't get much light into your lens, forcing high ISO and/or slow shutter speeds. You do not want slow shutter speeds at a dance. It just doesn't work.

What you DO want is a constant aperture zoom. They're designated by a single f number at the end of the lens. 17-55mm f/2.8 means it's constant. You can be at f/2.8 all the way through. 17-55mm f/2.8-5.6 means the above is true...2.8 at 17mm but by the time you're at 55 you're stuck at f/5.6. There are a lot of constant aperture lenses out there, from both OEM and third party manufacturers. Prices vary. OEM are always more expensive and the better choice if you can afford them, but the third parties can offer a good value if you're willing to compromise. These compromises can vary from lens to lens.

KEH.com is dominated by Canon as well. That's true everywhere except Nikon-only websites. It stands to reason...Canon has more marketshare therefore a bigger used market. Fredmiranda is still a good source for used Nikon...you just have to look harder.

[PHeller]

Ah very helpful. Accept I still have a Nikon. Ha!

I got the D50 as an early Xmas present because a family member found a good deal on it. (Better then anything online albiet used private party)

I've used the Canon 350D quite alot, and its an easy to use camrea, but my hands cramps after about 45 mins of use. Just not a comfortable camrea for me.

I'll jump into this head first, mess around with the Nikon, and a year from now, figure out which direction I want to go.

Canon does have allll that support, kind of like Honda in the auto industry, but some people just never have liked the Civic, although they make like Acura products. I liken the Civic to the Rebel's and the 20D/30D to the Acura's...and the 1D MarkII? ...the NSX and S2000...

and well...althought I like Honda's,I can barely afford a Civic much less a Integra. So I went with a Ford Escort. Cheap, older, but still gets the job done. Just harder to find suppport for.

haha...anyway...back to photography stuff.

[cdifoto]

Yeah I started out on XTs. Good image quality and pretty fast overall, but small. I added grips to both and it helped but the button arrangement sucked. I never did get used to making adjustments on the fly and always had to resort to Av mode. I now have a 30D and a 10D and feel no need for the grips and can make changes on the fly in full manual. I almost never go to Av mode anymore. The 10D is a step backwards in speed and image quality vs the XT but the handling is identical to the 30D and that means a lot to me. I was also able to get a used 10D for a few hundred less than I resold my one XT for, so I actually came out on top in some ways. Returning the problematic XT to Canon for a full purchase price refund (long story) and selling off the one grip and batteries paid for the 30D. Selling the remaining XT (not problematic) and grip and batteries and a few accessories paid for the 10D and put some cash back in my pocket. In my opinion it worked out rather well.

[mattdm]

The f1.8 is one full stop faster than f2.8. Your shutter speed will be a bit faster in low light at f1.8.


Specifically, one full stop is exactly twice as much light. This means your shutter speed can be exactly twice as fast. From f/1.8 to f/2.8 is actually slightly more than a full stop -- f/1.8 to f/2.5 is a full stop. (Or, f/2.0 to f/2.8.)


Using my 50 f1.4 lens to properly expose a subject here in my room.
Here are the shutter speeds I attained.

@f1.4 = 1/25 sec

@f1.8 = 1/20 sec

@f2.8 = 1/8 sec

Give or take rounding and metering errors, that seems about right.

[unix04]

if possible, borrow/rent a zoom lens with 2.8 aperture and see if it suits your needs. if it doesnt, you'll have to resort to primes.

[TNB]

Get everything then. An f/2.8 zoom for convenience and a few faster primes for speed. You really should have both anyway since you'll technically be a professional. You should also have a backup body just in case but since no one is paying you to show up then it's not such a big deal if your cam dies.
That appears to be the path I've been following since I just picked up a f/1.4 tonight. Of course, after shooting with someone on Saturday night who had the f/1.4 while I didn't, that's all it really took. Now it's time to hit a few more night time events.