I thought about that nice d850 with all those MPs, then read that the d750 with fewer MPs is a better gatherer of light, since each pixel is larger andore sensitive to light. I have read papers on this and am still confused. Some guys say you don't need anything over 12 or 20 or 25 MPs, while others are upgrading to the d850 or A7RIII and swear that the more MPs the better.

For my application, i will likely use a 300mm f2.8 prime with image stabilization. I will take that image and blow it up (crop) as much as needed to ensure we can get a positive ID on the subject.

I will shoot from inside a car because at my age (68), carrying a 9lb camera/lens combo while remaining invisible is too damn hard. Maybe I should hire some kid to push me around in a wheelchair??!?

Camera will also be used in a studio for other types of photography (when we are not out on the street) such as portraiture, macro, food, and products. So, while the Nikon Coolpix P1000 may be cool, it won't work for me. Need interchangable lenses, need Full Frame (or at least crop sensor), need at least 5FPS, and want but don't really need 4K video. Can get by with half way decent 1080 video, as long as parties are recognizeable.

Now I know most of you guys/gals are outstanding shutterbugs with superb resolution, no moire (whatever that is), great HDR, lo noise, no BD, and no CA, but for the outside nite shots, we aren't gonna be putting these in a gallery... a jury maybe, but only in a courtroom. For the other applications, yes, we will need as many of the good attributes as possible and as few of the negative (pun intended) ones as possible.

Think the choices have been narrowed down to Nikon, Canon, or Sony, and to a full frame. Beginning to think that a decent prime of at least 200-300mm with a large aperature, at least 2.8, is needed, to identify our target in low light 100 yards away. So, I think the lens manufacturers can be narrowed down to Tamron, Tokina, Sigma, and native.

Leaning toward D750 or D850, but still somewhat flexible.

REALLY GREATLY APPRECIATE ALL OF YOUR IDEAS AND SUGGESTIONS. I LOVE THIS SITE AND YOUR WILLINGNESS TO SHARE YOUR VAST KNOWLEGE.
THANK YOU VERY, VERY MUCH!!!

KEEP "EM COMING!!

I am a private investigator with experience since high school (class of '67), shooting Canon, Olympus, Minox, etc film cameras. For past 5 years, I have used Lumix cameras, most recently the DMC-TZ4, which has a nice f2.8 zoom lens. My question is this:
1. Which camera and lens combo would you use for the following conditions?
a. Target distance: up to 100 yards
b. Time: could be daytime or night (think of the goodnight kiss on the front porch with distant streetlight or porchlight or walking.to car in motel parking lot).
c. Maximum time from seeing target until target is out of sight averages 3-8 seconds, so can't waste time focusing/zooming, etc.
d. Generally, distance to target will be known in advance, and most shots will be taken from inside a parked vehicle which has 35% tinted side windows.

I'm thinking a D750 body, but have also been looking at the A7RIII. Would prefer to spend under $2,000 on the lens, as I have no other need for a tele.

I will also be using the body for other photography, such as food in a restaurant, products in a studio, commercial portraits, and exteriors of commercial establishments, thought nite shots are my bread and butter.

I like tilt screen; must have an EVF 'cause we don't want that screen lighting me up at night; must have some type of VR, OS, or IS, since we will be shooting hand held at night at high ISO and relatively low shutter speed (never over 1/250, and usuallyuch slower). Prefer dual slot, don't need more than 5 or 6fps (this ain't a sport, yet), wifi would be nice too.

Question 2.: am leaning full frame, but open to your suggestions, based on YOUR PERSONAL EXPERIENCE. New Nikon P1000 with zoom to 2400mm or 3000mm (125x) is nice, but can it do what I want on such a small sensor? Any reason DX is better than FX, other then weght/price?

Looking for those very few professional private investigators who are also accomplished photographers to weigh in here. Am getting ready to drive to B&H next month to cure my g.a.s. attack! Money is not a major consideration, though I am not wasteful. Would go D850, but don't see a need for that many MPs.

Photos don't need high res, just need to be recognizable for positive id in court. Many thanks to all of you in advance... I love UHH and have learned a lot in the past month or research, both here, on utube, and the various sites on the internet.
Mark