[lesliehui]

[img src="http://picasaweb.google.com.tw/lesliehuialbum/Oct09WetlandParkYuenLongPark?authkey=Gv1sRgCNbKmO2D2IC6_QE#5395269240892152754" width=400]


I am using 24~70mm f/2.8L Canon lens (Macro 1.3ft) and Canon 5D Mark II camera.

Camera setting :
a) Aperture = f/3.5
b) ISO 100
c) Shutter speed = 1/100 s
d) White balance = Sunny
e) Zoom with 70 mm at object distance = 10 inches approx (still can auto focus on butterfly)

I don't want to change the photo structure so I don't want to reduce the zoom to less than 70mm.

My problem (as you can see) is that the sharpness cannot be maintained for the whole flower (Centre of the flower is OK while its edge and surrounding flowers cannot be sharp).

I have tried to reduce the aperture to f/4.0 or below. However, the background image of the photo becomes sharp and it is not
my preferrence (Of course, it gradually solves my problem).

This problem happens very often in my close-up photos (e.g. flower, insect, etc).

So what is the reason of this problem ?

My suspects :

a) I have already used the minimum of marco (10 inches approx) to focus on butterfly. Therefore, the flowers in front of it cannot be focused correctly (because less than the minimum of macro length). But I have tried to focus on the most front flower and
this lead to the dis-focus of the butterfly.

b) It has a small wind blowing on the flowers.

c) I use a wrong lens to take this kind of close-up photo. Will other person use 70mm lens to take this kind of photo ? Or they
will use marco lens / 70~200mm lens ?

Please inform me the reason ans suggest the solution !

[lesliehui]

[lesliehui]

[lesliehui]

[img src="http://www.dcfever.com/photosharing/view.php?id=777052" width=400]

DCfever link :
http://www.dcfever.com/photosharing/view.php?id=777052

[Marksman01]

http://www.dcfever.com/photosharing/view.php?id=777052

This picture looks like back focus

Are you using AI servo for focus?

For preventing the hand shake I always use over 1/160 @ 70mm on 5D2

[tam_dominic]

幫手貼 :


F3.5 + 10" object distance + 70mm focal length
==> very shallow depth of field.

solution :
1. Set F8 to increase the depth of field. (you don't prefer this)
2. Use F8 then blur the background in Photoshop
3. Use F8 and set your own background
.... such as a piece of plain green paper.

Happy shooting !

[tam_dominic]

Guess how this totally sharp close-up butterfly is taken :

[lesliehui]

At first, thanks for Marksman01 & tam_dominic's explanation !

a) Markmans01 --- I am not using AI servo focus mode. I just use normal auto-focus mode. I know that 1/100s is not a safe shutter speed. I will use 1/200s next time. By the way, you said that the photo is back focus. That means (in such situation) I need to focus on the most front flower rather than the butterfly ?

b) tam_dominic ---- Would please tell me how to post the photo in this discussion forum ? I have tried many time but fail. On the other hand, I am interesting on how you can present your photo in such sharp condition, It is what I prefer in taking butterfly photo. Using photoshop to blur the background ? Tell me ! Ching !

[Marksman01]

lesliehui, you welcome, if you use one shot AF, the object will move away after the AF confirmation or your own body have a tiny movement before fire off (if it is handheld), then the super thin DOF will show you the OOF on the object.
Select an outer AF point and point to the eye of the butterfly in AI servo. And of cos you may need manual focus in some condition

[fgalen]

Actually the lens is not the macro lens. You may consider to try the new 100mm f2.8L Macro.

[Obi-Wan]

most zoom lens, even it labelled as macro DO NOT have the FLAT required for close up, try using a real macro lens for better result, e.g. 100/2.8L, sigma 150/2.8, tamron 90/2.8

[lesliehui]

Thanks Marksman01 again ! You have teached me one more technique for focusing on moving subject.

Thanks also for fgalen and Obi-Wan for macro lens suggestion. In order to increase the depth of field (by increasing the subject distance) and more flexibility on shooting girl photo. I am also considering for 70~200mm f/2.8L IS zoom lens. Of course, I know that prime lens will have better photo quality and more suitable for shooting flower & insect.

Hey, tam_Dominic. Tell me the answer please !

[tam_dominic]

b) tam_dominic ---- Would please tell me how to post the photo in this discussion forum ?

以下節錄自 "攝影基礎訓練" notes, 歡迎索閱
==========================================================
11. 如何在網上貼圖
......a. 先在 Dcfever, flickr, photobucket 等網站開個戶口, 將相放上去.
......b. right click 張相，再 click 屬性，可看見類似以下網址 :
http://203.194.133.168/media/sharing/09/06/12/81411244803379_l.jpg

將這全行 網址 取代以下的 xxxxxxx (這網址是應該 .jpg 字尾的)
[img src ="xxxxxxx">
也可指定張相濶度, eg 800點
[img src =”xxxxxxx” width=800>

Note : 要將最前的 [ 改成 <
==========================================================


On the other hand, I am interesting on how you can present your photo in such sharp condition, It is what I prefer in taking butterfly photo.
==> The large depth of field photo was taken by a Panasonic FZ50 with add on closeup lens.

Using photoshop to blur the background ? Tell me ! Ching !
==> It would be difficult to explain her.
Take a look at the following Photoshop plugin to see how much can be done :
http://www.alienskin.com/bokeh/examples-highlights.aspx#

影相後製是必須的, 愈早掌握愈好. <== 節錄自 "攝影基礎訓練" notes

Happy shooting !

[bmsmaster]

24-70 最近對焦距離： 0.38 米

10inch is too close to focus

[fgalen]

Another way is to buy an extension tube for your 24-70mm f28L