Ooops, my ignorance is showing!

[suzanne carey]

Hi there! I do have a dumb question for you today. Well, its more of

an educational question for me. I have recently purchased the 50mm

1.8 for my Canon 20D. I am enjoying this new lens. But I have

noticed when I use it on 1.8, the pictures are very, very soft. Is

this "normal"? When would you use it that open? But as I move it

down to like 5.6, the images are crystal clear. I will be using this

lens for mainly portrait work and at weddings. Any advice or books,

links you want to share so I can educate myself more...I am more

than open to any suggestions. I have read several books, but nothing

that was very specific on lenses and how to get a handle on them.

 

Thanks in advance!

 

Suzanne

[walterh]

Hi suzanne- I do not know that particular lens and without an example posted its hard to see if what you see is in the normal range. In general terms: Yes its normal. Even for 50mm lenses that are fairly easy to produce (in comparison to very wides or teles) one can see that "fast" lenses say 1.4 or 1.8 have a very narrow depth of focus and show less contrast used wide open. Another factor is that for many lenses the focal plane is not flat but actually curved. This will again be most obvious when the lens is wide open. All this can add up to very obvious "soft" images. Flare will also be more noticeable with a wide open lens. F 5.6 to F 8 is for many lenses the best opening for good contrast and good detail reproduction. For a typical 50mm F1.8 lens i would expect that the contrast and richness in detail will also decrease again if stopped down to F 11 and fairly pronounced at F16 and F22. Many aim to use F8 in cases where depth of field is fairly covered and contrast and detail are of primary concern.

[ky2]

Most "Softness" issues associated with fast lenses (f/2.8 and below) normally attribute to very shallow depth of field. Yes, the 50/1.8 will perform much better at f/5.6 -- but when you shoot it wide open, make sure you know what you're focusing on.

[mark u]

If you are using the lens at a wide aperture, you need to take special care over focussing. You should be using one of the creative mode exposure settings (probably Av or M) and you should manually select a particular focus point - don't leave the camera to choose automatically - and ensure that you focus with the chosen point over the part of the subject you want to be in sharpest focus (usually an eye for portraits), being careful to avoid any movement by you or the subject that could upset focus before you take the picture. Because the depth of field is very narrow at such a wide aperture, anything more than an inch closer or further will start to look less sharp if you're shooting at fairly close range. You will get a little more depth of field by shooting from a bit further away. One consequence of shooting with a very narrow depth of field is that backgrounds are thrown completely out of focus, giving a dreamy look, while the subject should remain very sharp and thus stand out. The technique is worth mastering, as it will give a more professional feel to your work.

[grant g]

There should also be something in focus...unless the shot is also suffering from camera shake because the shutter speed is too slow. For a 50mm on a 20D, you should try to keep the shutter speed over 1/80sec. unless you are pretty steady or using a tripod.

[steve_dunn2]

<p>The lens is indeed softer wide open than stopped down; the same is true of almost all lenses. Even by f/2.8 you should be able to notice that it's much sharper than it is wide open. The sweet spot for this lens is probably around f/5.6 or f/8.</p>

 

<p>As others have noted, shallow depth of field can fool you into thinking that the lens is soft, when in fact the problem may be that the image (or at least the part you care about) is simply not within depth of field. For instance, at f/1.8, with the subject 2m away, the DOF extends only a few centimeters on either side of the plane of focus with a 50mm lens on a 20D. If you, or your subject, accidentally moved just a few centimeters forward or backward, you will not get a sharp picture. With even less movement, some parts of the subject may be within DOF but most of the subject may not.</p>

 

<p>There's also the issue of where, exactly, the camera focused. The AF sensor may not be in exactly the same spot in the frame where the marking is, and it may not be exactly the same size as the marking (in fact, AF sensors are usually larger than the marking in the viewfinder). If something else was just outside the marked area, but within the area the sensor covers, the camera may have focused on something you didn't want it to - perhaps an eyebrow rather than the eye itself.</p>

[jim_simon3]

I can confirm that the lens is sharper wide open than I previouly thought. My DSLR had focusing issues which caused me to manual focus until I could get time to send it to Canon. All my shots were manually focused while using natural light on a toddler and the lens is sharper than I thought, but of course the narrow dof makes it clear that you can only interpret the sharpness at the point of focus. This also brings up the advantage of the 1.4 lens as manaully focusing the 1.8 is not user friendly.

[splat]

Please don't take this the wrong way but don't you think issues like this should be learned before you start doing paying work and weddings?

 

And yes the lens, like all lenses, gets better when stopped down a bit. Still, I don't hesitate to take pictures at f/1.8. I find them to be sharp enough for portraits. There is such a thing as too sharp when it comes to portraits too. At f/1.8 the 50mm prime is still head and shoulders above a 28-80 f/3.5-5.6 zoom at f/5.6. If you want things razor sharp don't use f/1.8 but don't let fear of softness prevent you from getting the shot. There are times when stopping down will spoil a picture far more then the softness of being wide open.

[marc_bergman1]

Suzanne,

 

On your Photo.net personal page the URL of your personal web page is incorrect. It comes up as:

<p>

"http://www.photo.net/shared/www.pumpkinpatchphoto.com"

<p>

It should be:

<p>

"http://www.pumkinpatchphoto.com"

<p>

For those wanting to see an example of Suzanne's work:

<p>

<a href="http://www.pumkinpatchphoto.com">Suzanne's home page</a>

<p>

[steve_dunn2]

<p>Little typo there ... there's a p missing. It should be <a href="http://www.pumpkinpatchphoto.com/">http://www.pumpkinpatchphoto.com/</a></p>

 

<p>I would also agree, without intending it as an insult, with the comment about learning mechanics and technique before turning pro. I think you have a good eye, and you take pleasing pictures. But in a field of endeavour where equipment must be used, it's important also to have a solid understand of how the equipment works, and how its settings relate to the task at hand.</p>

[albert lui]

Petteri wrote a great article on the Canon fifties: http://194.100.88.243/petteri/pont/Reviews/g_Fifty_versus_fifty/a_Fifties_duel_--_f1.4_vs_f1.8.html

[suzanne carey]

Thanks guys so much for all the information! You confirmed my understanding of the lens. I will bookmark this thread as a wealth of knowledge. Thanks again for all the suggestions and feedback. I am sharing a picture I took of my daughter the first weekend I got the lens. I take pictures with it everyday and with the new Tamron I got, which I love, to get a better understanding of the mechanics. I think I am on the right track, and how could I not be with all the great help you guys offer!<div></div>

[walterh]

Suzanne -good luck. You will do fine - after all its easier to pick up the technical part than the good eye ^^

[steve_dunn2]

<p>I definitely second that last comment! There is no way I could ever be a portrait photographer. Well, for that matter, there's no way I could ever be a professional photographer of any sort, but I'm particularly unsuited for portraiture. I could learn all the mechanics and techniques and have great equipment, and someone with a good eye and a sense for posing could whip my butt with a cheap point and shoot.</p>

 

<p>Like I said, you have a good eye. You'll do well; just keep looking for information. General photography texts, books on portraiture, magazines, the static content and old forum articles from sites like this, there's lots of info out there if you can find the time to sift through it all.</p>

[suzanne carey]

Again, thanks so much for the positive feedback. I cannot tell you how good that makes me feel. I can handle the honest feedback as well but its much nicer getting positive feedback too! :)