macro flash question

dutchie

Senior Member
I have a D7000 with a 55mm micro lens.
I find that the pictures I capture look rather hazey unless I use my speed light.
Is that normal?

Thanks
 

Marcel

Happily retired
Staff member
Super Mod
What apertures are you using without the speed light? When you get to macro, sometimes you get so close that the lens is cutting the light away from the subject.

Maybe if you'd post example shots we'd be able to help more...
 

dutchie

Senior Member
Hey Marcel I think It may be the DOF may be the real issue.
on a couple shots certain areas are ok and otheres are blurred.
I will try to post a couple pics when I get a chance.
thanks for the reply!
:)
 

Marcel

Happily retired
Staff member
Super Mod
well just look at your exif infos for different shots and you should find out that with the flash (speed light) you get a much smaller aperture which in return creates larger depth of field and also prevents motion blur since the flash duration is so short. I know that I also get sharper shots with the flash when doing macro so I think it's normal.
 

Whiskeyman

Senior Member
Hey Marcel I think It may be the DOF may be the real issue.
on a couple shots certain areas are ok and otheres are blurred.
I will try to post a couple pics when I get a chance.
thanks for the reply!
:)

What subject-to-camera distances are you working with?

I have a Nikkor 105 Micro and was counting on reduced lens aperture to increase DOF (Depth of Field) and found that at maximum reproduction ratio distances (i.e., very close) the DOF didn't increase much, if at all, until stopped down to f/16 or more. To really get a big change in DOF at that distance, stoping down to f/22 is needed, while I needed to work at f/32 or smaller to get close to what I wanted in depth of field. However, my photos were too underexposed at that aperture.

The old Nikkor 55 mm Micro lens DOF tables show the same characteristics. For instance, at the minimum focus distance of 25 cm, aperture settings from f/5.6 to f/11 have a ephemeral DOF of 2 mm (249-251). At f/16 and f/22, the DOF increases to 4mm (248-252), an increase of 2mm over the previous values. Stopping down to f/32, the DOF increases to 7mm (247-254), over three times the amount you get with apertures as small as f/11.

Increasing the distance from the camera from minimum focus distance to 30 cm (for the 55mm), the DOF for f/16 goes to 9 mm(296-305); for f/22, 13mm (294-307); and for f/32, 19 mm(291-310). Doing so decreases your reproduction ratio from about 1:2 to 1:3, but your DOF increases by a factor of nearly two to three.

Increasing your subject to camera distance gives even more DOF. If you can get the reproduction sizes you want when doing so, you might be better off increasing your camera to subject distance instead of just stopping the lens down to increase DOF. Also note, the focus distances are subject-to-focal plane distances, not subject-to-front lens element distances.

This cropped photo was taken with a D90, AF-s 105 Micro at 1/200 sec and f/8, and handheld. It has a very shallow DOF.
Dragonfly-2.jpg

Have some fun experimenting with macro (Micro) and let us know how it works.

​WM
 
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