View Full Version : need help with aerial phtography....
5th of February 2007 (Mon), 04:00
because of some gratis photography i did for our municipal police helicopter patrol unit's website, i've been offered a fantastic opportunity to fly with them on one of their patrols as a way of thanking me for my work.
they've also asked me for some advice on what type of camera equipment they should acquire while on patrol for use as gathering photographic evidence from 200 meters and below, and they also want to fly me on their patrol route to give me a feel for what would be a good setup for them.
i told them sight-unseen that a 30d with 100-400L glass would be practical, as it would present a weight/cost-saving and manueverable combination as opposed to a cumbersome 1d series and 400 2.8L combo or higher. i'm just not certain if the 100-400L glass has enough reach for them at that height.
i did warn them that if they attached a 1.4 TC to the 100-400 and used it on the 30d ,they would be limited to manual focus, but would have AF if they used 1d series bodies.
i don't know yet what kind of budget they're limited to, as i haven't spoken to the pilots on that specific point.
if any POTN members have suggestions that may be helpful to their cause, i'd be most grateful if you'd share with me.
this is a pic i took of one of the 'copters they use for patrolling:
5th of February 2007 (Mon), 20:57
I shoot from a helicopter all the time and for what they would use it for I would suggest a 1DMKII with a 100-400 IS. Tell them to look at the ALEA (Aviation Law Enforcement Assoc.)
website for what other police units do.
5th of February 2007 (Mon), 21:05
osteo, thanks for the info. i will certainly pass on the tip.
6th of February 2007 (Tue), 04:03
Completely OT, I just had to say it though.
That is one wicked copter pic you've got there. And what a cool experience it must have been.
6th of February 2007 (Tue), 09:36
what type of camera equipment they should acquire while on patrol for use as gathering photographic evidence from 200 meters and below
i told them sight-unseen that a 30d with 100-400L glass would be practical
i'm just not certain if the 100-400L glass has enough reach for them at that height.
I'm not an expert on aerial photography or the evidential requirements of law enforcement officers, but I do understand geometry. Let's assume you're using the 30D and a 400mm lens.
From 200m up, if you look straight down you'll be photographing an area about 11m by 7m on the ground. So each pixel represents an area about 3mm across.
From lower altitudes, scale everything proportionately; e.g. from 100m the field of view is 5.5m x 3.5m and each pixel represents an area about 1.5mm across.
If you're looking down at an angle of 45 degrees (more realistic I guess) then add 50% to everything; e.g. from 200m the field of view is about 17m by 11m, etc.
6th of February 2007 (Tue), 10:03
I recommend one of the 1 series cameras for the basic principle that they can put the image verification device to work, which will improve the chances of using the images in court.
Also depending on multiple factors, a 100-400 will be close if at that maximum of 200M, the reason is shooting straight down you will probably not see faces, so you need to shoot off nadir (term for straight under the aircraft) this can add another 200+M to the distance you are shooting at. They probably need to have positive identification of faces. The better AF system and viewfinder will also help.
So since you may need to add the extenders ( 1.4 or 2x ) the 1DsMkII may be a better choice. If Canon had second generation IS on the 100-400 that would be even better. because that aircraft is going to be bouncing around the sky relative to the target at that distance and IS helps a lot in that case.
While I am technically an expert in Aerial photography, It has been awhile since I did the math and I didn't do that specific application. My experience tended to be at 500 Nauts or faster at 15,000 feet or higher. Not quite the same.
Note I would tell them to wait a few months if they can to see if Canon announces something with the resolution of the 1DsMkII and the speed of the 1DM2N at PMA. That would be what I get if I were them.
6th of February 2007 (Tue), 10:08
i don't know yet what kind of budget they're limited to, Let us know when/if you get an idea.
6th of February 2007 (Tue), 21:11
thank you all for the valuable info and kind words.
20DNewbie, thanks for the compliment. i need all the encouragement i can get. sad to say, it's one of only a few pictures i've taken where i'm not too embarassed to post here on POTN. i'm sure all of you here at POTN would've done a better job.
StewartR, thanks for the very useful info. it will definetly come in handy. my geometry is quite rusty. as such, i appreciate your help. gee, who knew i needed to apply geometry toward picture taking? ;)
Longwatcher, i've learned quit a bit from your post and i appreciate it much. you've made me much more aware of the "extra" or "third" spacial dimension that needs to be considered when taking pics at altitude. very nice to read the staight scoop from a person with your experience in aerial photography. thanks much.
PhotosGuy, i just checked my inbox and have received a reply from one of the pilots concerning their photo equipment budget and my scheduled flight with them. i'll post back with details on this subject soonest.
again, thank you all for your help. it's just great that there are so many folks on the POTN forums that are knowledgeable and willing to help others. :)
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