SCHLUMBERGERA

Simbad · Post by **Simbad** » Sun Mar 27, 2011 4:21 pm

Hi

I post these pictures here because it is my first post on this forum.

I hope you will enjoy them.

SCHLUMBERGERA or Thanksgiving Cactus

I used a Canon T3i + 18-55 mm Lens + Close-up filter 1x, 2x, 4x, 10x stacked

Gerald

rjlittlefield · Post by **rjlittlefield** » Sun Mar 27, 2011 4:35 pm

Simbad, welcome aboard!

These make a good first post -- colorful, fun to look at.

I'm not sure what's meant by that word "stacked". It could mean that you added multiple close-up lenses on front of your 18-55 lens. Could also mean that you ran multiple images through software to get extended depth of field by focus stacking. Could be both! Can you clarify?

One reason for my curiosity is that I'm seeing quite a bit of CA (chromatic aberration -- red & blue color fringes), especially near the edges of the images #2 and #3. That often happens when more than one closeup lens is used, but even a single closeup lens can do it for some combinations of lenses.

--Rik

Simbad · Post by **Simbad** » Tue Mar 29, 2011 7:22 am

Hi

I did both. I used Zerene Stacker to stack many picture. The first image has less cromatic aberrations because I used less filters.

I just bought my camera last week a Canon T3i. This is my first Reflex camera, so I used what I already own to shoot close-up photography. I am looking for a macro lens. I think it will be a Canon EF 100mm f/2,8 Macro USM as soon I will have the money to afford it. May be next month or the month after, depend what my accountant(my wife) will say.

Gerald

rjlittlefield · Post by **rjlittlefield** » Tue Mar 29, 2011 10:09 am

Sounds like you are well on your way. That Canon macro has an excellent reputation.

Another idea to keep in the back of your head is to use a close-up lens that is higher quality and/or better matched to your camera lens. The Raynox series has an excellent reputation. I have the DCR-250. Putting it with my Canon 18-55mm zoom, it gives field sizes from about 2.2 inches wide down to about 1.2 inches wide, depending on zoom and focus. There is significant pincushion distortion and curvature of field, but it's virtually free of CA and the resolution is pretty good at f/16 (which is the only point I've tested). You can also put it on say the 55-200mm and get a lot more magnification. The Raynox certainly does not compete with a real macro lens, but on the other hand it's only $60.

Switching subjects... There's a great feature of the T3i that you may not have run into. If you put it in Live View and shoot without flash, then the exposure is started electronically -- no shutter or mirror movement -- so you can get very sharp images even with continuous illumination. The magic word for searching about this is "EFSC" (electronic first shutter curtain). More info HERE and in the surrounding thread.

--Rik

rjlittlefield · Post by **rjlittlefield** » Tue Mar 29, 2011 10:25 am

rjlittlefield wrote:You can also put [the Raynox DCR-250] on say the 55-200mm and get a lot more magnification.

I just checked this, for curiosity. It goes down to about 12 mm across the field, with good sharpness and flatness at f/16, but a noticeable amount of blue/yellow CA in this case.

--Rik