Canon APS-C Portrait lens and Bokeh ?

kc4sox

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I've been shooting a 5Dmk3 for over a year now. And while I love the body it isn't well suited as a sports and wildlife camera. So, I'm going to sell it because I find myself wanting the extra "Reach" and speed of an APS-C body for sports and wildlife. I'm looking at the 7Dmk2. I would like to be able to use the body for portraits as well . I'm a HUGE fan of Bokeh / separation in portraits. And, I understand the relationship of F stop / focal length and distance to subject in relation to bokeh on a FF body. I need advise on lens that will give that nice OOF background and reasonable working distance when using an Crop sensor body such as the 7Dmk2. Am I correct in assuming that a lens such as a 50mm f 1.4 ( APS-C factor of 1.6 = 80mm f 2.24 ) would give me results similar to what I get with my 5Dmk3 and say an 85mm f 1.8 as far as the OOF area in a portrait ? And if my thinking is on track would that also mean that the same 85mm 1.8 I mentioned would work as well and give similar results as a 135 f 2.0 ? ( 85mm f 1.8 x 1.6 crop factor = 136mm f 2.88 ) The math alone says I'd get what I'm looking for but, I have no experience with a crop body.

Thanks is advance

Michael
 
That math only works if you are shooting the same subject at the same spot.

So for example, yes, if you are used to a 5D shooting a 85mm f/1.8 and now starting shooting a 7D with a 50mm @ f/1.8, you'd get about the same results as the 85mm at f/2.8 in terms of DOF and Bokeh. This assumes very similar framing.
 
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What you get with a crop body is a reduced field of view by the crop factor. A 100mm lens has the field of view of a 160mm lens on a 1.6 crop.

i.e., extra reach.
 
I use the same lenses on my digital camera with the APS-C sensor and on 35mm film rangefinder cameras. Yes, standing in the same place shooting with both, the field of view is different and the pictures look as if I was using a longer lens on the digital camera than I actually was. Makes it seem as if I was 'in closer'.

I think you're talking about the depth of field. The bokeh is the quality of the out of focus parts of an image; that seems to be better if you have a better quality lens (more aperture blades, to make it less choppy looking).
 
I guess change the terminology to make everyone happy.

Not a matter of being happy.

It appears the OP is under the impression he's going to get additional focal length by going to a crop body. I was simply trying to explain to him that he is in fact not going to.

You mention changing terminology. I cannot for the life of me figure how you can tie focal length and field of view together to the point where you can use the same term, reach, for both.

This is an interesting illustration from, of all people, Canon, that helps show the effect of a crop factor. If you'll notice that whatever the focal length is set the FOV changes with a crop, not focal length. Canon DLC Field of View Comparator

I thought that was the idea here. To try to help others when we feel that we can contribute.

If you all care to continue to believe that a crop body is going to increase your XXmm focal length lens to a XXmm times your crop factor then knock yourselves out. Keep saying it over and over pretty soon it becomes fact.

To you.

Some of us understand the difference and are not concerned to the point you are. Posting a link as you did helps those that want a better explanation and to show their lens does not magically change.

I know the difference of what a bird looks like when I shoot it with a crop sensor opposed to a full frame sensor. That difference is what is important to me no matter what I call it.
 
People that click that link are going to see one camera that produces a closer image than the other and think to themselves: wow, a 300mm lens on the crop sensor has a lot more reach.
 
even if they read it.
 
and they wont be wrong.
 
define reach.
 
ie,
the Field of View will look like you are zoomed in on a crop body camera. It uses less of the image circle from a general FF lens.
So with a crop body camera you would have to stand further back if you used the same lens to get the same Field of View.

a FF with an 85mm vs a crop & 50mm, at the same distance might be the same Field of View image but then you also have to take into account any distance distortion too.
ie, being closer to a subject may instigate distortion - larger noses, slimmer faces and stuff like that.

general sensor stuff ==> Digital Camera Sensor Sizes How it Influences Your Photography

using wide angles up close ==> Using Wide Angle Lenses

it all comes down to how you define "reasonable working distance". When I tried to do portraits in my basement I ran out of "reasonable working distance". a FF camera solved that. Just try in your "studio" to take 10 to 20 steps back to simulate a crop body. Use the FOV calculators out there to figure out the distance that you need.
 
If you want better bokeh, stick to full frame camera, which produces better bokeh than APS-C camera. Check out the discussion here (FF vs. Aps-c DOF Bokeh Photography Forum

The "extra reach" with APS-C camera ( whether you call or believe it or not, I think it's useless) is not worthy to switch from full frame.
 
If I understand this whole crop sensor - full size sensor thing.
If I take the same lens (say 100mm) and put it on a crop sensor and also on a full frame and take the same picture. I can put the two photos in Photoshop on separate layers and the photo from the crop sensor will overlay right on the center of the full frame picture and line up perfectly. Just as if the crop sensor shot was a crop of the full frame photo.
Ignoring other technical details about the two cameras - is that correct?
 
The "extra reach" with APS-C camera ( whether you call or believe it or not, I think it's useless) is not worthy to switch from full frame.

It's not 'useless' if you can't otherwise get close enough to your subject in order to get the photo you want.

It's simply a trade off. In this case the OP desires extra - whatever you call it, and faster burst speeds.

OP you may need two cameras. FF to keep your field of view, depth of field, lens bokeh wishes. Crop for your wildlife and sports desires. Or purchase a 1Dx along with a $10k lens. Problem solved.
 

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