The images were all taken from midday-to-midday on 16 and 17 April and the contest was  open to anyone with a camera or a mobile phone.
The overall winner was Paolo Ferla who took "Electric Bristol" - a picture of the Clifton Suspension Bridge.
Megan Witty, from 24 Hours In Bristol, said the judges had had "an incredibly tough job" picking a winner.
The competition involves entrants being "randomly allocated" one hour of the day or night in which they must take at least one photograph.
Mr Ferla, from Bath, said he was "delighted" to have won.
He said he used a 10 second self-timer and then ran into the shot.
"Ten seconds is not very long so it took quite a few attempts - when we got there the sky was still quite bright, so we sat there for nearly 20 minutes waiting for the sky to get darker.
"It's a beautiful bridge and as soon as the sun sets on it and the sky gets darker and the electric lights come on - it just comes to life. "
Ms Witty said the six judges "didn't always agree" and one said it had been "heartbreaking" for some not to win. She said about 75% were taken on cameras and about 25% on mobile phones.
The exhibition is at the Harbourside Arts Centre near Millennium Square and runs until the middle of June.

Pars goalkeeper Sean Murdoch denied Jamie Adams in a first half of few chances before two quick fire goals put the visitors in control.
El Bakhtaoui raced on to a Ryan Wallace ball to score his first, before scoring a stunning 30-yard volley from Michael Paton's cross.
Craig Moore fired a late chance over for Ayr United, who remain third.

The second round of group games include must-win matches for England, against Uruguay, and Spain, who face Chile, after both teams suffered defeats in their opening fixtures.
Brazil and Mexico are the first teams to play their second game, on the same day as the opening fixtures in Group H. Those results are also included in Lawro's predictions.
Before the tournament, Lawro picked his two teams to go through from each group and reach the knockout stage.
He is backing Argentina to win the World Cup and lift the trophy at the Maracana on 13 July, and believes England will reach the quarter-finals.
Lawro was speaking to BBC Sport's Chris Bevan.
Brazil 0-0 Mexico
Read the match report.
Cameroon 0-4 Croatia
Read the match report.
Lawro's pre-tournament picks to go through: Brazil and Mexico
Australia 2-3 Netherlands
Read the match report.
Spain 0-2 Chile
Read the match report.
Lawro's pre-tournament picks to go through: Spain and the Netherlands
Colombia v Ivory Coast (19 June, 17:00 BST)
Read the match report.
Japan v Greece (19 June, 23:00 BST)
Read the match report.
Lawro's pre-tournament picks to go through: Colombia and Ivory Coast
Uruguay v England (19 June, 20:00 BST)
Read the match report.
Italy v Costa Rica (20 June, 17:00 BST)
Read the match report.
Lawro's pre-tournament picks to go through: England and Italy
Switzerland v France (20 June, 20:00 BST)
Read the match report.
Honduras v Ecuador (20 June, 23:00 BST)
Read the match report.
Lawro's pre-tournament picks to go through: France and Switzerland
Argentina v Iran (21 June, 17:00 BST)
Read the match report.
Nigeria v Bosnia-Hercegovina  (21 June, 23:00 BST)
Read the match report.
Lawro's pre-tournament picks to go through: Argentina and Nigeria
Germany v Ghana (21 June, 20:00 BST)
Read the match report.
United States v Portugal (22 June, 23:00 BST)
Read the match report.
Lawro's pre-tournament picks to go through: Germany and the United States
Belgium v Russia (22 June, 17:00 BST)
Read the match report.
South Korea v Algeria (22 June, 20:00 BST)
Read the match report.
Lawro's pre-tournament picks to go through: Belgium and Russia
Hundreds of photos of Bristol taken for a competition to show "24 Hours in Our City" are on show.
[NEXT_CONCEPT]
Faissal El Bakhtaoui netted a second-half double as League One leaders Dunfermline claimed victory at Ayr.
[NEXT_CONCEPT]
BBC Sport's football expert Mark Lawrenson is predicting the outcome of every game at the 2014 Fifa World Cup.