Not much depth of field...

[300+]

I ordered some $10 extension tubes from ebay and had a play today.

There isn't much depth of field... This is a coffee bean - 7mm across.

http://www.reddock.net/aulro/DSC06767-Edit.jpg

Cheers, Steve

[Mick-Kelly]

Can you not adjust DOF a bit with aperture.

[dmdigital]

I'm glad you said what it was as it looks like a ... :wasntme:


Nice and sharp. What lens did you use with it and how long an extension?

[300+]

This is my el-cheepo sony 18-70 kit lens. It might have been sharper if I'd used the other lens, but I'm quite impressed with this one. To keep my life simple the 2.8 is on the camera and the kit lens now has the tubes permanently attached.

Took me a while to get it focussed though. I bluetacked the bean to a translucent tupperware pot which you can see in the background. This was on a white bench top and the tripod set to bench height. I found it easier to move the bean to focus than it was to adjust the camera.

I used all three tubes in the set 7, 14 and 25mm (I think) for a total lenght of 46mm. This was with about 35mm on the zoom lens. I had to take the filter off the lens to allow the bean to get closer to the front element at one stage!

Cheers, Steve

[300+]

Can you not adjust DOF a bit with aperture.

Due to the el-cheapo contactless tubes the aperture control is manual. I had it about half way closed. Any more and the viewfinder was too dark to focus with.

I guess I could have gone for fully closed and used the screen to focus. But given the effective light loss in the tubes the exposures were long enough. A coffee bean doesn't move much, but if it was a flower or insect there would likely have been some movement if I'd ended up with a 10 second exposure. I think this was about half a second.

Cheers, Steve

[dmdigital]

Open the aperture right up so you can set up the shot, get the focus right, then step the aperture back to where it needs to be. Even so the aperture is going to be razor thin.

I bought Kenko tubes for the reason they have the contacts for the lens. I thought it was worth the extra it cost me.

[300+]

Why didn't I think of that...

[Chucaro]

I just wonder if a diopter will not give better results that this image with cheap extension tube.......

[300+]

The tubes were an impulse buy (I was shopping for a hot shoe spirit level) so I didn't research much.

Would a dioptre give this level of magnification?

Cheers, Steve

[Chucaro]

It would be easy for you to read THIS (http://nocroppingzone.blogspot.com/2007/06/using-canon-500d-diopter.html) page than understand my spanglish :D

[300+]

There you go. Most of the magnification whilst still maintaining the lens functions such as aperture, etc.

Cheers, Steve

[austastar]

Hi,
If you want the best optical performance for macro work but don't want the expense of dedicated macro lenses, bellows are the next best thing. Some bellows are made that allow you to reverse the lens and this is a good feature.
This puts the object closest to what was the rear lens element, and the film (now ccd) at a further distance from what was the front element of the lens.
Bellows can also have the advantage of having an inbuilt rack for fine distance adjustment.
On my old setup, I had twin cables on the cable release so that I could focus at full aperture, preview the image stopped down and release the shutter with one press on the button.
Having said all the above, if you really want to do a lot of macro work, go for a macro lens. My favourite was a Nikon 105mm, 1:1 to inf. with a twist of the wrist.
cheers

[dmdigital]

The tubes were an impulse buy (I was shopping for a hot shoe spirit level) so I didn't research much.

Would a dioptre give this level of magnification?

Cheers, Steve
No - work on the fact that you had a 7mm coffee been right in front of the 35mm lens. At best the diopter closeup lenses will give about a 2:1 where as the tubes can give better than 1:1

[300+]

Outside shots are harder. I managed not to get the web stuck to the lens, but the slight breeze meant it kept swaying and this was the sharpest I could get.

http://www.reddock.net/aulro/DSC06980-Edit.jpg

Cheers, Steve

PS the jpeg compression look really oversharpened....

[Mick-Kelly]

For outdoor work i would only use a proper macro lense. How does the shrpness look in RAW without the compression?

[300+]

Fuzzy is the short answer. It isn't quite in focus except for a couple of legs. However, I've been reading online about lab sharpening, which seems to have created a more realistic result, which is still quite sharp. There is also a lot of noise as this was at 800ISO. Knocking the noise back doesn't help with the shaprness...

http://www.reddock.net/aulro/DSC06980-Editlab.jpg

Cheers, Steve

[Chucaro]

Removing the noise in the BG will help a lot. Try to do a strong denoise in the BG and a weak on the insect.
Do a color range selection/white and tone down the whites. This will help to reduce the oversharpening look.