A focal length is a focal length? (is a focal length?)

[newbie81]

Is focal length the same for all types of lenses?

***If I have a telephoto lens at 100mm and a macro lens at 100mm, and I stand in the same spot/use a tripod... will the captured image be similar in proportion?

-For example, I have a telephoto zoom lens (EF 70-300mm f/4-5.6 IS USM)

-I want to purchase a macro lens to take portraits at a friend's wedding.

-I was thinking about purchasing the Canon 100mm Macro lens because it is EF, not EF-S and therefore full frame. Other forum topics say this 100mm lens is great for portraits and offers a good working distance. I just can't imagine the 100mm macro being a good portrait lens if you have to stand so far away from the subject(s).

-My concern is that the working distance is too far. When I use my telephoto lens, I have to stand about 20-25ft away when it's at 100mm in order to get someone's head and shoulders in the frame. It'd be even further away if I want to get 2 people in the frame and some of their clothes and background as well.

-In summary, is the working distance at 100mm on the telephoto lens the same as the working distance on a 100mm Macro lens?

[Ronald S. Jr.]

You're gonna have to have some serious distance between you and your subject on a crop body to get a head and shoulders shot at 100mm. make sure you have the room. As for the focal length...100mm is 100mm. At a certain working distance (within a few inches), the macro will snap into "macro mode" and show you depth of field. However, at that distance, you wouldn't be taking headshots, even. 100mm is 100mm. Period.

What body will you be using?

[kevin_c]

Yes !

[newbie81]

Thanks for the replies, I have Rebel XT

[Ronald S. Jr.]

Yeah, that's gonna be pretty long on that body. From any normal portrait distance, we're talking headshots (literally). What type of portraits are you looking to take? Full body? Couple? Head and shoulders?

[Andy_T]

The macro lens is more useful than the 70-300 when you want to get headshots of ... bugs :D

Ths only difference between a macro lens and a regular lens of the same focal length is that the macro lens lets you focus very close on small things (say, 5 inches away), while a telephoto lens needs some minimum working distance (e.g. 3 feet away). If you want to use the lens to fill the image with the head and shoulders of a person, you will have to be at exactly the same distance as with your 70-300 mm lens.

Maybe you should be looking at a good 'normal' lens (e.g. Sigma 24-70/2.8, Tamron 28-75/2.8 XR DI) or else...

Best regards,
Andy

PS: Welcome to the forum :D

[Ronald S. Jr.]

If the ol' budget isn't too tight, a 50 would probably help you a fair amount. Nice for portraits. 50 1.4 would be the way to go, at about $300. If you can squeeze out $600 instead of $500 (what the macro costs), you could get the 50 1.8 instead. Still a nice portrait lens.

[Wilt]

Newbie, the 100mm recommendation for conventional portraits ONLY applies for 35mm FF cameras!!! The 1.6 crop format would use about 60-65mm lens for the same shooting distance to subject and achieve the same framing.

[Madweasel]

Is focal length the same for all types of lenses?

*** Other forum topics say this 100mm lens is great for portraits and offers a good working distance.
Hi Newbie81,
Lenses with focal lengths of 85-105mm are traditionally called portrait lenses, but that is from 35mm days. Obviously this is unchanged if you have a full-frame digital body, but with a 1.6 crop (like your Rebel) you'd be better off with a 50mm lens if you want a prime, or something between 50 and 70mm to give the same sort of working distance.
Macro lenses can double as protrait lenses as they have similar focal lengths, though some find them to be unflattering as they are designed for maximum sharpness (although these days a little post-processing can easily soften the image).
Hope this is helpful.

[Wilt]

newbie, a macro lens is something that someone uses if they wish to get extra close to the subject. You do NOT want to get extra close to your subject, unless you're a dentist taking a shot of the molar with the brand new porcelain crown on it (and not see any portion of the surrounding face in the shot!)

[jojohohanon]

I've found a good trick for seeing what's in field of view for various lengths, on my XT body, for when I don't have it with me. I've noticed that 85mm covers just more than a loose fist at arm's length (head and shoulders 10-12 feet away, ish). The 50mm covers a diagonal just bigger than the widest hang-five I can do with my right hand (once again, at arm's length). From testing a very long time ago, a 135 is roughly the coverage of a squarish ok sign with my thumb and forefinger.

FWIW, the 50s (the cheap 1.8, and the better, but 3x more pricey 1.4) are very highly regarded. If you do want the macro feature as well, the EF-S 60mm is rated as one of the sharpest lenses canon makes, but not nearly as useful in low-light as the 50s.

You can experiment with the coverage of these lenses using your kit lens, which is 55mm at the longest end. 50 - 55 - 60 is a very small difference.

[StealthLude]

mmmmmmmm 50mm 1.4 & 100mm macro.

2 of my next lenses.

[newbie81]

Did I get caught up in all the Canon hype?

http://www.usa.canon.com/consumer/controller?act=ModelDetailAct&fcategoryid=139&modelid=11154

Click on "Using IS and Macro lenses for Better Photos" -- they state:

"Macro lenses are ideal for taking portrait photos." Are they lying? :confused: Or is it just the 60mm one that's good for portraits?

[Ronald S. Jr.]

No, they're not. Macro lenses are insanely sharp. This could be a bad thing, though, as it brings out any imperfections when it's too sharp. You may want to peek at this (http://photography-on-the.net/forum/showthread.php?t=171753) for one type of fix for that problem. Another problem is that they're slow to focus (just an inherent characteristic, unfortunately). Mind you, the 100 macro is but one of the 3 <100mm macro lenses. There's also the 50mm f/2.8 macro, and the 60mm macro, which is an EF-S.

[SkipD]

Did I get caught up in all the Canon hype?

http://www.usa.canon.com/consumer/controller?act=ModelDetailAct&fcategoryid=139&modelid=11154

Click on "Using IS and Macro lenses for Better Photos" -- they state:

"Macro lenses are ideal for taking portrait photos." Are they lying? :confused: Or is it just the 60mm one that's good for portraits?You may be misunderstanding some of the things they are saying. Regarding focal lengths, Canon often refers to the EF lens series as if the 35mm format is the only thing out there. The real problem is that even they don't often explain which body format the lens they are talking about is connected to for their recommendation. That happens a LOT on these forums too.

You will need to learn what focal lengths to use largely by experience. However, for portraits using the XT (or any of the other APS-C sensor bodies), the best recommendation for ordinary portraits in ordinary home studio settings is the 35mm to 65mm range. Some folks go outside that range, but usually after experimentation for their particular desires. For a single portrat lens recommendation, the Canon 50mm f/1.4 lens on the XT can't be beaten for average situations.