Canon 85mm prime on a crop sensor

braveboy2012

braveboy2012

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Gary
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Hi all,

So with a baby on the way I am planning on getting a new prime lens for around the house (mainly). I already have the 50mm 1.8 but was looking at getting the 85mm 1.8 which a lot of people seem to say is great for portraits and the best non L lens around.

My only worry is the minimum focus distance, 85cm is quite far, especially for indoors. I wanted to check what that would look like in terms of composition/framing and then came across my question:

I have a crop sensor (550d) and an ef-s lens in the form of a 55-250. If I set that lens to approximately 85mm and hold the front of the lens 85cm away from the subject, would that be comparable to what I would see if I had the 85mm ef lens fitted?

I know that if an ef lens is fitted, my effective focal length would be 85x1.6 so would that be what I should set my ef-s lens too?:thinking:

Thanks in advance guys,

Gary
 
I'd be considering a 35mm f/1.4 (or the f/2 that's been mentioned recently) for your crop sensor. :)

A lot will depend on how much you're willing to spend but for my own little girl (who's almost 11 months old now) I tend to use my 50mm f/1.4 for most shots... Even on a crop body. :)
 
Bear in mind that lens focusing distances are measured from the focal plane, ie sensor, so front of the lens will be a bit closer than quoted.

And just to confuse things, depth of field calcs always use distances measured from the front of the lens - makes a difference when you're close.

Edit: and BTW, setting your 55-250 to 85mm should be right, but at close distance the focal length markings will not be accurate compared to a prime. It's called 'focus breathing' and can make a big difference with a lot of zooms. Focal lengths are only true at infinity focus.
 
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I think 85 maybe too much, I found 50mm too much with my friends 2 n 4 year old indoors, its ok if you want headshots tho
a sigma 35mm 1.4 would cover you better, specialy as baby gets more active.

maybe find a baby sized teddy or doll, and try the different focal lengths
 
Hi Gary I hovered over this decision before our little boy was born back in december. I already had the 50mm f1.8 like yourself, but I fancied something more. I had 35mm, 60mm and 85mm as my choices. In the end I just decided to go with the 85mm. The wider aperture of f1.8 is lovely and can be very effective when used on babies.

I have been doing a 365 project and a big percentage of the pics have been on the 85mm. I wouldn't be without it. But as he is growing bigger 85mm is a little restrictive inside as you will be wanting full body shots. So that's where the 50mm comes in. I have come across occasions where something wider than the 50 would help, but being indoors the background can become very obtrusive, unless you have a nice area which you can set up.

I also use a 50-200 sigma which is a great versatile little zoom, I have the 50 if I don't need the f1.8 of the prime and I have a little in between that and the 85.

I have a 365 thread running on here and all of my images are in a set on flickr with the exif available too which should give you an idea.

Also do you have a flash gun? You will find it very useful.

Hope that helps :thumbs:
 
Thanks for all the comments guys. I will have a play with some teddys (not literally!) and my existing lenses to get an idea of what will work in my house.

Michael, I will be sure to look through your shots when I get home.

Gary
 
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