bellgamin Loc: Ewa Beach, Hawaii

Say that I want an upper torso shot of a person 100 yards distant. What size tele lens would I need to get this shot? I ask this question just as an example. What I am really hoping is that someone can give me a rule of thumb for answering "how long a tele" questions such as the one in my example.

Aloha from Hawaii. The temperature right now is a chilling 76° F. Brrrr!

RichardTaylor Loc: Sydney, Australia

Have a look at the dimensional field of view calculator:

http://www.tawbaware.com/maxlyons/calc.htm

Drive by Shooter

how much can you spend on millimeters and megapixels? The Tamron 150-600 is incredible for the price when you don't need superfast autofocus. 24mp will let you crop out most of the shot and still have enough for a 5x7. so if you're not printing posters, crop before you spend outrageous sums on long glass!

Manglesphoto Loc: 70 miles south of St.Louis

I have a question for you. Have you ever viewed a person at a MEASURED 100 yds with the naked eye?

sb Loc: Florida's East Coast

For such a distance, the formula is: "how much money you got? + how much lens can you hold?" .....

DaveO Loc: Northeast CT

Or a naked person with a measured eye at 100 yds??

alx Loc: NJ

Aloha from New Jersey. The temperature right now is a balmy 33° F. (Hey, it's above freezing!) Oh, did I forget to mention that it's snowing? Jealous? You bet I'm jealous!

Joe Blow

While anything above 400mm will work, you will most likely need a very stable platform. Even use a remote shutter. You will need to enlarge and crop the photo some for it to be isolated on your subject.

Beware, however. https://www.usatoday.com/story/life/people/2017/05/02/paparazzi-on-trial-over-topless-photos-of-british-royal-kate/101206160/

rjaywallace Loc: Wisconsin

Just ask your caddy, that’s what you pay him/her for.

wilsondl2 Loc: Lincoln, Nebraska

Folks he asked the question for 100yds as an example. For 100 yds the longest lens you have. You didn't say crop or FF. My advise take a day and go out and see what each of your lenses will do. - Dave

bellgamin Loc: Ewa Beach, Hawaii

Oof! Until now I have never owned any lens longer than 135mm so I had no idea that 100 yards was such a long distance for taking a picture. In Hawaii I have visited surfing beaches where the surfers were quite some distance offshore. There were photographers there on the beach, making movies. I later viewed one of the movies and the surfer was very up close and we viewed his ride all the way in. It was amazing. I remembered that the lenses looked long to me that day at the beach, but not so long as to make me say Wow!

No rule of thumb for doing distance-to-MM estimates was offered so I suppose that none exists. I had hoped to photograph surfers but I see that doing so won't be practical for now. That is.... from the comments here, it seems my idea of shooting close-ups of people at distance would mandate use of a lens that would (a) give me a hernia using it, and (b) empty my billfold for quite a while.

Even so, this is an interesting thread. I learned from it. I am going to look into acquiring the Tamron 150-600 suggested by Drive-By. If I can afford it, I will likely buy it. Otherwise I will start dropping hints at family get-togethers ... I have a birthday in a few months.
Yes, I have. I had end zone tickets for an Alabama vs Texas U game. In the first half, I was at the 'Bama end of the field, so much of the best action was at the other end zone. So I was watching stuff mostly about a hundred yards distant. The second half was visually better because 'Bama was scoring right in front of us. Obviously, TU got smashed.

blackest Loc: Ireland

Approximately :) 1238 mm for a 1.5x crop sensor distance of 100 yards and a subject height of 6 feet.

https://www.cambridgeincolour.com/tutorials/camera-lenses.htm

1765.3 mm for full frame.





Your formula :

Object height on sensor (mm) / focal length (f, mm) = Real Object height (feet) / Distance to Object (d, feet)


for a 1 foot bird standing about 10mm high on a sensor with a 300mm lens = (0.033) = 1 ft / 0.033 = 30 feet.

it would be around 60 feet with a 600mm lens. I don't do birds really.

rehess Loc: South Bend, Indiana, USA

My birding kit - 300mm lens mounted on Pentax Q-7 {1/1.7" sensor} - would come close

Bobspez Loc: Southern NJ, USA

Very true. I don't believe there is a camera lens that would take just a torso sized area at 100 yards. Attached is a 130 yard shot with a 300mm lens on a Nikon J1 (810mm equivalent focal length). It's uncropped, but if you view it at 100% resolution with the download and + buttons you can see quite a bit of detail on a torso sized area on the street sign or the back of the car.

(Download)

SharpShooter Loc: NorCal

It would be pretty easy to figure out by using the angle if view but if I had to guess I’d say about 2000 mm on FF if it were at 100 yards without cropping!!!
Yes it was 76 degrees here a couple days ago too but it rained some today!!!
Welcome to the Hog!
SS