50mm vs 85mm

[WadeCourtney]

Other than the distance I have to stand away from the subject, is there any difference between a 50mm 1.8 and a 85mm 1.8?

I've been shooting a lot of fashion stuff lately and I'm not happy about the photo results.

[Shokinen]

You'll get a bit more compression with the 85mm. This mean the nose / eye in focus using large aperture (small f-number) will be easier to acheive. This is why many portrait photographers like longer focal lenght better. They also gives more space between you and your subject and sometime it makes them more comfortable.

To really understand what compression is, take 2 picture with your current equipment. The first one with something close to 35mm and the second close to 200mm. Try to get the same picture: this mean you will be much closer with the 35mm than the 200mm. Choose the biggest aperture you can (this mean the smaller f-number) but it also has to be the same for both pictures. Notice the difference in the background.


Can I ask why you are not happy ?

[OsmosisStudios]

Originally Posted by WadeCourtney

I've been shooting a lot of fashion stuff lately and I'm not happy about the photo results.

Without examples and specifics it's hard to say, but I'd wager that it isn't a lens issue but a lighting issue.

[inkista]

Originally Posted by WadeCourtney

Other than the distance I have to stand away from the subject, is there any difference between a 50mm 1.8 and a 85mm 1.8?

If you frame identically, then DoF and shutter speed needed to control camera shake blur are going to be slightly different.

In terms of the lenses, the EF 85/1.8 is a USM mid-grade Canon lens, vs. the consumer-grade EF 50/1.8 II. The USM allows for faster, snappier, silent autofocus, and the build quality and manual focus features are substantially better than those on the 50/1.8. The 85/1.8 USM, however, does tend to be very prone (like most fast lenses) to purple fringe when shooting wide open at specular highlights, so if there's a lot of metal/jewelry in the shot, stopping down would be a good idea.

If you need full-length shots, though, the 85 could also put you farther away from your subject than you'd like. Running around a Comic-Con with one on a crop body, I found myself running backwards a lot, and I far prefer using a 35/2 if I'm getting full-length shots of costumes.

[WadeCourtney]

Originally Posted by OsmosisStudios

Without examples and specifics it's hard to say, but I'd wager that it isn't a lens issue but a lighting issue.

Here is one example, and you're right it's lighting too. I just wasn't able to achieve the DoF that I wanted.

I was also using my speedlite for the first time, so there is some learning to be had there


Evelyn by Wade Courtney, on Flickr

[LoveDSLR]

Originally Posted by WadeCourtney

Here is one example, and you're right it's lighting too. I just wasn't able to achieve the DoF that I wanted.

I love to tag along with my 85 f/1.2.

[OsmosisStudios]

You're at f/3.5 in that shot. What kind of Depth of field were you looking for?

Also keep in mind that to get this shot you'll have to stand further away (you're at 31mm at your example) and your perspective of the scene will change drastically.

[WadeCourtney]

Originally Posted by OsmosisStudios

You're at f/3.5 in that shot. What kind of Depth of field were you looking for?

Also keep in mind that to get this shot you'll have to stand further away (you're at 31mm at your example) and your perspective of the scene will change drastically.

I was using a 17-70 for that shot.

I wanted a blurry background.

[OsmosisStudios]

Originally Posted by WadeCourtney

I was using a 17-70 for that shot.

I wanted a blurry background.

Then you're going to need some very fast apertures (think f/1.4), especially if you wanna stick around that 30-35mm range (for the same FoV). Sigma make an epic 30mm f/1.4 lens.

You could go longer, but you'll be changing the image perspective considerably.

Frankly, I like it the way it is. Your lighting has a rather specific hot spot: while harsher light is appropriate for this kind of shot, that hot spot is distracting. She needs a bit of makeup there to reduce the glare.

[idb]

Originally Posted by WadeCourtney

Other than the distance I have to stand away from the subject, is there any difference between a 50mm 1.8 and a 85mm 1.8?

I've been shooting a lot of fashion stuff lately and I'm not happy about the photo results.

Since your camera, the Canon 30D, has an APS-C sensor these lenses are effectively 80mm and 136 mm in terms of field of view being captured by the sensor. So they are both good portrait lenses.
In terms of depth of field the 50 has more dof than an 80 and the 85 has more dof than a 135. This is not effected by sensor size. In my opinion, this is probably an advantage in fashion and portrait work.
They are equally fast lenses (f/1.8) which also allows you to decrease dof by choosing a larger aperture, and they are probably also good quality so this should include using them at full aperture.

That's about it.
Btw, I like the shot you gave as an example but why didn't you use a shot taken with either your 50 or your 85?

Ian