I currently own 1D Mark lll and I absolutely love it. My style of shooting has always been sports and wildlife. My question is, my first Grandchild is coming and I know I will be taking a ton of pictures...lol. Wondering if a FF camera would be better for this style shooting.
I have a many different lens, but none I think are good for portraits on a crop camera. 85mm is way to long.
I am looking at the 6D and the 5D Mark lll. If I go FF. My 85 will see a lot more use and was thinking of also picking up the 50mm 1.8 STM lens.
Any suggestions for good lens to use if I just use the 1D and don't go FF would be great.
All suggestions welcomed, thank you.
Heya,
TL,DR Version:
1D3 + 24mm / 35mm / 50mm (or 24-70 / 28-75) would be my suggestion, and an ETTL flash (bounce). No need for a full frame at all for this at all. Not important. Makes no difference.
Flash makes the difference.
Stress on the ETTL Flash. Flash is the single more important thing, ever, when it comes to grabbing photos spontaneously inside where you want clean images to remember faces of kids from. ETTL bounce flash makes this super easy. You flick it on, and shoot. Indoor houses are dark, way dark for cameras. Natural house light is awful for photos too. Some houses are better for light, but let's say it's early morning or late evening and there's no awesome window light going on, just house lights, it's gross--you want a flash. A good flash will save your bacon and get you more memories than any other lens or sensor will, a flash is the bang for buck when it comes to spontaneous indoor photos and kids. I can't stress it enough! Natural light just never has the "pop" that a well placed bounced flash shot does.
Willing to read version:
So, a 50mm on your 1.3x APS-H will look very similar to what 70mm on full frame would look like. Quite similar to 85mm on FF. Perfectly good for headshots, busts, baby shots, etc. When the kid(s) are older and running around, it's perfect for outdoor full body shots, etc, without having to be way far away, and still has a pleasing isolation from F1.8. The 50 STM is fantastic regardless and is excellent for these things, and cheap (and quiet!).
I use 1.3x APS-H, 1.6x APS-C and Full Frame with the same lenses for portrait with my kid. Makes no difference. All that matters is working distance really, and how close you want to have to be, versus how far away you could be, etc. The sensor and focal length together really just influences working distance if you think about it. It doesn't inherently matter what you use, it's what you combine. There will be minor depth of field differences, but beyond that, no other real difference honestly for portrait in most aspects of it. Even then, that's assuming environmental/ambient/spontaneous portrait, and not just studio setups where it absolutely matters not at all what sensor you're using, shooting at F8 with lights, etc, or something like that. For natural light, spontaneous, around the house, etc, a fast lens with less reach might be preferred to be able to be "in the moment" instead of having to be 20 feet away to get a full body shot, etc.
There is no focal length that is "portrait." It's all about working distance. There's no lens focal length that causes distortion either, it's distance to subject that causes distortion. People use more telephoto focal lengths traditionally with classic portraits because it forces a longer working distance--and that distance, being farther from the subject, means no distortion. A 35mm for example will not make a bulbous nose on someone on a portrait inherently, but if you do it at very close distance, then it will--because of the distance.
One of my favorite around the house lenses for my kid on a crop (APSH & APSC) is the 35mm, and I often am using a flash too (bounce).
On my full frame, I use anything from 35mm, 50mm and 90mm depending on my goal (with or without light).
And I prefer full frame outdoors with 90mm or 200mm depending on my goal (with or without light).
I do a lot of spontaneous around the house chasing with the kid.
I also do formal setups and do outdoor strobe portraits and indoor strobed portraits in a studio setting (less often, but we do formals at mile stones).
I honestly don't recommend getting a full frame just for shooting portraits of kids around the house. It's literally kind of pointless unless you're trying to get the thinnest depth of field possible, and you want to combine it with F1.2 or F1.4 glass, etc, or if your glass was all already telephoto (85mm and longer only) it would make sense. But really, for around the house shooting of a kid on a crop, I'd look at APS-H & APS-C + 28mm, 35mm or 50mm and be good to go. Or just use a fast 24-70 F2.8 zoom with that and be good to go.
You don't want ultra thin depth of field on a moving kid--you will have a lot of stuff out of focus and you can't get that shot back, they grow up over night (as you well know I'm sure!). So shooting at F2 or F2.8 would be as wide as I'd suggest to anyone with kids starting out who are not already well accustomed to it.
+++++++++++
Examples from a crop of spontaneous around the house stuff:
I used my 1Dc & 1D II a lot with my daughter (~2 years old) as well as XSi, T4i, EOS-M, etc.. Favorite lens was easily 35mm, but also used 22mm, 40mm (pancake) & longer (85, 90 & 200) But I've used anything from 35mm to 200mm with my daughter running around.
1Dc (4MP!) + 35 F2 IS + bounced flash --- Flash made this photo happen, it was late night in the house, dark, and the flash just made it work.
225H7332_mark by Martin Wise, on Flickr1Dc + 35 F2 IS
225H7534 by Martin Wise, on Flickr1D II (8MP!) + 200 F2.8 (natural light, just getting face shots outside while playing with supreme isolation and close range)
LE1M3923 by Martin Wise, on Flickr1D II + 35 F2 IS
LE1M3809 by Martin Wise, on FlickrOr, more studio approach indoors with lights:
APS-C + 35mm + Flash
DPP_0630 by Martin Wise, on FlickrAPS-C + 35mm + Flashes
IMG_9321 by Martin Wise, on Flickr++++++++++++++
So again, summary:
Any focal length. Whatever you need for working distance. 24mm, 35mm, 40mm, 50mm are all safe bets. Sensor size doesn't matter. What matters is the relationship of sensor size and focal length and the effect on distance to subject for field of view.
More important: get comfortable and skilled with ETTL bounced flash inside so that you can always get the shot with the right light, far, far, superior to house light! Outdoor isn't a problem, inside is the issue. You want flash.
One last thing: flash.
Very best,
Now I just need to start shooting. 
