Quote:
Originally Posted by phelan
^ i was debating to myself for a bit to invest in an external flash or not. i've generally gone on the presumption to not use flash for anything yet, as i'm still learning the ropes, but i've taken more than one shot where i wish i could bounce some light off the ceiling or get some good fill.
and aperture does control DOF, ken. i think nick was pointing to that later in his post, as your f/stop increases, the sharpness also starts crawling out towards the edges.
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hey phelan. yep, i understood that part and nick's explanation. what didnt' come to me was that up to about 20mm length the rear DOF is infinite vs using a longer lens based on the DofF calculator. which means i shouldn't need to use a large f/stop number to get the tail of my car in focus.
here's wat the calc says based on me standing 3meters from the car using f/5.6
18mm near focus limit 1.17m DOF: infinite /far focus limit is infinity
20mm near focus limit 1.33m DOF: intinite /far focus limit is infinity
23mm near focus limit 1.53m DOF: 65.18m /far focus limit is 66.72m
that's a lot of dept of field i can use at f/5.6 with a short lens.
on the contrary if i use a 55mm setting...
55mm near focus limit 2.56m DOF: 1.02m /far focus limit is 3.594m
Quote:
Originally Posted by Nick911sc
When you shoot wide open, you get more of a DOF so the center is in focus but as you move away from the center you begin to get out of focus. So if you're shooting wide open at say.. 1.8 as you move away from the center it will begin to lose sharpness and if something is further away you'll get the blurring(bokeh) in the photo. So if you take that same lens and boost the F/ to 4 more of the image will be in focus including things that may be further away from the focusing point. The mm of the lens itself does not really effect DOF. If you shoot at 90mm with 2.8(like my macro shots or at macro 1:1 with a higher F stop which is a totally different lesson lol) you're getting that same DOF effect.
IMO an external flash increases picture quality 10 fold. But natural light I find better obviously in situations like shooting cars.
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yah, so you're saying that the camera's center is focus based on apeture and DOF and you can selectively focus using the REDDOT but the apeture setting will mandate how well the camera can focus within that DOF. i think i understand how this thing works now.
forgot to reply on your question about flash. i dont have external flash, just the one that pops up on my D3100.
i dont intend to go deep into photograpy. i already have another expensive hobby (music) besides my car which not only eats at my wallet but my time and determination as well.
photography is more like just a icing on the cake for my car hobby.
