[Cideway]

Whoa there chuckie. The kit lens (like most zooms) slows down as you get towards the long end. So it's not f3.5 it's f5.6

In this case, the f3.5 @ 18mm results in a shallower DOF than 55mm and f5.6.

In you case, buy the twin kit 'cos it's insanely priced and to buy then on their own will cost hundreds more. Then save for a 50/1.4.

Okay, not having ever used the Kit lens (let alone seen one) i can only mke guesstimates based on what i know. All things being equal, the 55 at f5.6 would give you less DoF then 18 at f3.5, in fact you can stop the 55 end down to f32 to get the same DoF at 1m as the 18mm produces at f3.5 at 1m. Irrespective of the DoF you SHOULD be shooting the portraits at the long end anyway, simple because of the personal space issue and perspective issues, the 55 allows you to be further away for a similar framing thus flattening perspective, it also reduces the background that is recorded and people prefer shots of themselves when their nose isn't 3 miles wide.

[Finn]

Okay, not having ever used the Kit lens (let alone seen one) i can only mke guesstimates based on what i know. All things being equal, the 55 at f5.6 would give you less DoF then 18 at f3.5, in fact you can stop the 55 end down to f32 to get the same DoF at 1m as the 18mm produces at f3.5 at 1m. Irrespective of the DoF you SHOULD be shooting the portraits at the long end anyway, simple because of the personal space issue and perspective issues, the 55 allows you to be further away for a similar framing thus flattening perspective, it also reduces the background that is recorded and people prefer shots of themselves when their nose isn't 3 miles wide.

OK, I'll retract my previous comment, now that I've thought on it a bit. My usual portrait lens is the A 50/1.7, which is obviously a better focal length. But seeing how babies don't get freaked out when you're eight inches from their face, I thought I'd test the limits of the kit lens. Shortly after that photo was taken I had a few drooly fingerprints on the lens as a result of my efforts...

[kyrios]

@raz: For children portraits, i highly suggest you to buy the AF version. FA 50/1.4 is perfectly suit for you. Use f2.4 or higher for children portraits. In my experiences, even at f2.0 using SMC 50/1.2, the DOF still shallow.
Almost all of my children pict is unusable due to FF or BF. I was using SMC 50/1.2
I can't ask him to sit or pose gently becoz he's still 2yr 9 month old. It make me frustrating becoz i can't focus him well. Sometimes he move aside from his position and he never won't look at the camera. Never.
Becoz of this, today i just purchased a faster AF for my children portraits, DA 70mm f2.4. In the next 2 days it will arrive at my door. Can't wait that moment.
Meanwhile here's 2 pics of my son. SMC 50/1.2 at f2.0 (you'll see some FF and shallow DOF)

[raz]

thank you kyrios, those are great portraits! My kid is exactly 1 year old and he's almost running already and doesn't rest for a second...I think I will have the same problem as you

Yes, I'm planning to buy the FA 50/1.4 with the help of nystateofmind27

[nystateofmind27]

Yes, I'm planning to buy the FA 50/1.4 with the help of nystateofmind27

....

[mickeyobe]

Finn,

Please do not take offense but you have taken a dreadful portrait of a very beautiful child.
You were much, much too close. Just look at how you have distorted the face.
You should use your 55mm to give you the 35 mm camera equivalent of an 82 mm lens or an even longer lens if you have one.

Everyone seems so concerned about depth of field. You cannot change the laws of optics.

Either move the baby away from the background or hang a baby blanket or some other suitable backdrop behind the baby. It is just that simple. No complicated formulae or calculations.

The 18 mm ( 27 mm in 35 mm camera terms ) should not be used for portraiture unless you do not like the subject you are photographing and want to grossly enlarge the nose and distort the features. Try taking a picture of yourself while holding the camera in your hand to see the results of getting too intimate. Then post it here just for fun.

Take a look at Kyrios' beautiful pictures.

I do think the K100D kit lens is a good buy with which to start - and continue.

Mickey

[nosnoop]

Please do not take offense but you have taken a dreadful portrait of a very beautiful child.
You were much, much too close. Just look at how you have distorted the face.

Mickey, I am sure Finn did that on purpose.
What you said is only true for studio, wedding.... or commercial type of portraits. For kids, casual or artistic portraits, I use all focal lengths. Your creativity should not be limited by the narrow mindset of constitutes "ideal portrait focal length".

[mickeyobe]

nosnoop,

There is a difference between "portraits" and "people pictures".
The former is generally considered 'formal' and the latter, "anything goes".

I fully agree with
"Your creativity should not be limited by the narrow mindset of (what) constitutes "ideal portrait focal length".
but Finn seemed to be talking about formal portraits and his picture of the baby appears to be an attempt at that.

I have used everything from a magnifying glass to binoculars to a telescope to eyeglasses and yes, the bottom of a Coke bottle and the usual battery of reverse rings, extension tubes, bellows and even pin holes.. More out of curiosity than artistic endeavours. It's fun, interesting and educational - the beauty of an SLR.

Mickey

[PDL]

Back when I used to shoot 35mm I tried to use my 135mm short telephoto to shoot what few portraits I did. Gave me enough space to work with to where I was not so close that the subject could count the hairs on my head (no need to worry about that now). As for understanding the function of DoF you should check out
Hyperfocal Distance and Depth of Field Calculator - DOFMaster
I do not know if you are using a PC or Mac - but having this nice little tool around has been very educational to me since the DoF changes given the size of the sensor. Oh - I shoot Pentax DSLR's/FSLR - Fu*ica FSLR's and 4x5. This calculator covers it all.
As I have not shot any portraits with my DSLR's I will have to defer to an co-worker who has established a nice little weekend career shooting portraits - booked for several months out at the moment - He shoots C*non but he really loves his 85mm prime. He also uses a 28-75mm zoom, but stays above 50mm most of the time.
PDL

[Nando]

Unless a 50mm lens is all that I have with me at the moment, I rather use a slightly longer focal length for portraits. On my rangefinders, I use a Voigtlander 75mm/2,5 Heliar that lets me shoot from a more comfortable distance and has a shorter DOF than a typical fast 50mm. It's also gives very creamy bokeh. For my Pentax, I looked for an 85-90mm portrait lens and settled on a Soviet Helios 40-2 85/1,5. Its a huge and heavy (1kg) lens but its magical wide open. The Soviet Jupiter-9 85/2, which is a copy of Carl Zeiss 85/2 Sonnar, is much smaller and also gives stunning results. The latter is more practical and very inexpensive even if you factor in the cost of a m42-K adaptor. I just couldn't resist the lure of the Helios.

I would still get a good 50mm prime since that focal length is very versatile. My my SMC-PM 50/1,7 is a great lens. Very sharp and gives reasonably nice bokeh wide-open for portraits. However, given that a SMC-PM or A 50/1,4 is not much more expensive, it's certain worth getting over the 50/1,7. I use the 50/1,7 because it came with my camera and I'm quite happy with it.

[Finn]

Finn,

Please do not take offense but you have taken a dreadful portrait of a very beautiful child.
You were much, much too close. Just look at how you have distorted the face.
You should use your 55mm to give you the 35 mm camera equivalent of an 82 mm lens or an even longer lens if you have one.

Everyone seems so concerned about depth of field. You cannot change the laws of optics.

Either move the baby away from the background or hang a baby blanket or some other suitable backdrop behind the baby. It is just that simple. No complicated formulae or calculations.

The 18 mm ( 27 mm in 35 mm camera terms ) should not be used for portraiture unless you do not like the subject you are photographing and want to grossly enlarge the nose and distort the features. Try taking a picture of yourself while holding the camera in your hand to see the results of getting too intimate. Then post it here just for fun.

Take a look at Kyrios' beautiful pictures.

I do think the K100D kit lens is a good buy with which to start - and continue.

Mickey

What can I say? Babies are funny looking, and a little distortion just adds to their charm...

Yes, it was very much on purpose. I have quite a few more photos posted on my Flickr site linked below, most of which were taken using one of various 50's, and more recently the FA 31. If I wanted to just lay a blanket or something behind him, I might as well just take him to Sears...

[clm]

Finn,
I liked it. I think it works because his expression seems to say "Are you nuts? You have to use the long end of the zoom! The other forum users are gonna tear you a new one..."

[Finn]

Well I certainly didn't mean to give anyone palpitations for posting a portrait not done "the right way"...

I'll correct my deviant ways. From now on I'm only doing 3/4 profile, 50 or 70mm at f/4, and a neutral background...

[Cideway]

Well I certainly didn't mean to give anyone palpitations for posting a portrait not done "the right way"...

I'll correct my deviant ways. From now on I'm only doing 3/4 profile, 50 or 70mm at f/4, and a neutral background...

Not arguing about the merits of wide angle portraits, i was simply commenting on the D0F equations.

[Finn]

Not arguing about the merits of wide angle portraits, i was simply commenting on the D0F equations.

...and my comment was not actually taking issue with yours, so we're square!