35mm, 50mm or 85mm?

I know the subject is ominous ... he he he

For years film cameras were sold with 50 or 55 mm lenses and those lenses are still popular and highly recommended.
When asking about prime lenses I always see the 50mm 1.4 or 1.8 suggested.
There are full frame and crop cameras so I am a little connfused as to the 'real' recommndation being made. In othe words, if you have a full frame camera and buy a 50mm lens then that is what you are getting. Many people recommend 50mm and 85mm for portrait work. If those same lenses are put on a 1.6 crop then the focal lengths are really 80mm and 135mm respectively. If a 30mm or 35mm lens is used then the effective focal length is closer to 50mm or 55mm.
So with a crop camera would you use the 35mm to achieve the 50mm, or would you use a 50mm, giving you 80mm? I would think that using an 80mm or 85mm is already too long for most portrait work because that would be like using a 135mm lens.

So what makes the most sense when thinking in terms of 35mm equivalents on a 1.6 crop camera?

I think technically the 35 will give you the FOV closest to 50 mm (25x1.6=56mm). On an APS-C sensor (crop sensor) the focal lengths are still the same 85mm is 85mm, but the image that is recorded on the sensor is a crop of the rectangle that you would see on a FF camera or essentially the FOV of the focal length times 1.6 (85mm gives FOV of 135mm).
There was a pretty good link somewhere here that explained that.

Of course I'm pretty new to the "crop factor" too, but this is what I've sorted so far.

Hey Steve,

I understand that the 35 mm will give me the effective 50 or 55mm but my question is which lens is recommended for something like portrait work? Do I want to achieve 50mm by using a 35mm lens or do I want to use a 50mm to get an effective 80mm? 50 is always being recommended but I don't know if these recommendations are coming from those using FF or crops.

you can use any mid to long focal length for portrait work. if you are really doing portrait work then, go for the 85mm. the longer focal length and low f/stop will really pull the subject from the background and leave the background nice and blurry.

ChopstickHero wrote in post #2085022
you can use any mid to long focal length for portrait work. if you are really doing portrait work then, go for the 85mm. the longer focal length and low f/stop will really pull the subject from the background and leave the background nice and blurry.

Ok so if I understand correctly, based on using a 1.6 crop camera you are saying that the 50mm is the lens to use because it will give me the 85mm focal length desired. Correct?

I am concerned about a longer focal length because I don't have a large amount of space and if I am going to have the subject about 6 feet in front of the backdrop I can only position the camera about another 10 feet from that.

I think the 50mm is a really good choice on a 1.6 crop camera for portraits. An 85mm can be too long for all but tight head and shoulder shots indoors, and you are probably going to be a bit too close to your subject with the 35mm (although great portraits are still possible, especially, say, from the waist up).

I've got the 35mm f2 and it's a great 'normal' lens on a 1.6 camera for general shooting - portraits, outdoors in the street, parties etc etc, and produces very sharp pictures too.

if you are limted by space, get the 50 and feet zoom in and out for the shot you want, if you have space, id say get the 85mm, itll be more versatile in and outside of the studio, mine oughta be on its way, i feel too limited with the 50 outside, i have to walk a lot in and out of places i feel i can get the perfect shot

the 50 1.8 is about 70 USD, if you can stretch funds, 400 ish, get the 85 1.8, AND the 50 1.8, perfect prime combo in my opinion, perfect for most portrait setups

I believe historically 50 mm is the portrait lens of choice with FF because of the perspective given. I agree with everyone else about the 50 and 85 and here's my added 2 cents...

6 to 10 feet the 85 is to long, I own it and and can tell you that only head shots will be given within say 15 feet. I don't own the 50 but must on this forum use it for portraiture.

Here's an example from about 15 feet that I posted before..sorry the resize effect IQ,thanks to my wife

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If you like TMR I can do some measured shots for you this weekend...not sure what you timing is on this?

steve_shelly wrote in post #2085138
If you like TMR I can do some measured shots for you this weekend...not sure what you timing is on this?

Thank you Steve. That would be great. This is not something I am going to get right away. I am going to get the kit lens with the 30D and figure out what I need the most. I just want to have an understanding of how all this works.I can see that the primes are much faster and from what I gather will produce better bokeh on portraits.

If I set the kit lens to those focal lengths (35, 50 and and 85) will that give me an idea of what to expect so I can determind which prime lens will best suit my needs?
The price on the 50mm f/1.8 is very attractive.

Hi TMR...yes setting the kit lense at those focal lengths will do the trick remembering that focal lengths are always the same regardless of which body or lens you use.
Yes Primes are much faster and from what I here the 50 1.8 is the best bargain you can get on a good fast prime.

If you can buy body only and add the 50 rather than the kit lense I would do that or pick another zoom. From my personal experience the 18-55 kit was not worth the increase in price from body to kit with my 20D, but MANY people have gotten great copies of that lense.
When I purchased the 20D I got the 18-55 and then added the 28-135 IS USM, at that time the 28-135 just killed the 18-55 and I never touched the kit lense again. I have since replaced the 28-135 with a 16-35 and the 85 and I'm extremely pleased with the combo I have. I don't have all the range yet, but the wifey keeps a strict leash on my hobbies (this is just one). Next purchase I believe to be the 300 f2.8 in the spring...yeah right who am I kidding, but what to do with all the disposable income..hmmm..

I'll set up the measured test and add it to the 85 lense archive for ya

While I normally wouldn't suggest getting the kit lens, it will let you try out a couple focal lengths you're interested in. If you're doing studio type stuff and shooting at f/8 or more, the kit can deliver just fine with some post processing. I'm using it some now to test out the 35mm focal length for myself...

From www.the-digital.picture.com, regarding the 35 f/1.4:

That said, it sounds like you have plenty of room indoors to make fine use of the 50.

The reason mid-telepohoto lengths are recommended for portrait work (on a full frame camera) is that they allow for sufficient subject-to-camera distance so that the subject's features are pleasantly proportioned and not exaggerated by perspective error - i.e., with a wide angle lens, you have to get close to the subject to fill the frame and this has the effect of elongating the nose and chin and otherwise making the photo unflattering. Of course, the same photo taken with a wide angle lens from the same distance as an 85mm lens and then cropped to the same subject size would not show this distortion, but the resolution would be significantly affected - which is why the 85mm is better on a FF camera.

On a 1.6 crop camera, you'll get the equivalent field of view (FOV) with a 50mm lens as you would with an 80mm lens (but not the same focal length), and therefore you would be at essentially the same camera-to-subject distance as with an 85mm lens on a FF camera for the same subject size.

Mark

TMR Design wrote in post #2084920
So what makes the most sense when thinking in terms of 35mm equivalents on a 1.6 crop camera?

lenses that were designed for aps-c bodies:

17-50mm = 28-80mm
17-70mm = 28-105mm
50-150mm = 80-240mm
30mm = 48mm

then you've got other lenses that will also work very well on aps-c bodies:

50mm = 80mm
85mm = 135mm

On full frame or film bodies, the standard lens for portraits was usually 85-100mm, possibly 135mm if you are doing tighter headshots. On an aps size sensors this translates into 50-60mm or possibly 85mm.