Search found 27 matches

by PanoGuy
Tue May 22, 2012 6:11 pm
Forum: Equipment Discussions
Topic: Not All that Glitters is Gold
Replies: 96
Views: 30010

Has anyone tested this lens at less than the designed magnification? Say 10x? The large image circle and good quality at different magnifications are one of the great things about the 21mm JML.
by PanoGuy
Wed May 02, 2012 7:10 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Shedding Light On Moss from Behind: A Flash Experiment
Replies: 10
Views: 4616

I really like the 2nd image with the dark background.

Have you experimented with cross-polarization? That would let you eliminate a lot of the direct reflections from the flash (or adjust them to taste).
by PanoGuy
Tue May 01, 2012 5:49 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Beetle stereo with errors!
Replies: 4
Views: 1608

They've been cloned-out of the left image. There are indicative repeating patterns in areas like the hair near the upper right and the two adjacent spots at the middle top.

Neat image NU. As Rik said I also had incorrect assumptions about the structure from a single image.
by PanoGuy
Thu Apr 19, 2012 3:31 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Ruminations about confusing stacks
Replies: 15
Views: 7293

Could the effect be due to a change in magnification at different focus points? It looks like you have inverted perspective in the animated mitutoyo image, so the far section starts out large then decreases in size as the focal point moves toward the rear of the subject. This would also likely have ...
by PanoGuy
Fri Mar 09, 2012 8:17 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Stack alignment using specified regions
Replies: 2
Views: 1533

ChrisR, In addition to the halos the "normal alignment" version of the branch is blurrier than the "branch alignment" version. The small highlights also tend to become smeared somewhat. It's not so bad here, but more frames/movement would make it much worse. The program takes the source images, alig...
by PanoGuy
Fri Mar 09, 2012 4:11 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Stack alignment using specified regions
Replies: 2
Views: 1533

Stack alignment using specified regions

Had an idea to improve stacking results for some projects, and thought I'd share the technique in case anyone else wants to implement it: I shot several live moths using a stack-and-stitch approach, only to find out later that despite appearing perfectly still they had in fact moved slowly over the ...
by PanoGuy
Sun Nov 06, 2011 6:00 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Vespula germanica 5X with JML 21mm
Replies: 15
Views: 3445

Have you tried shooting a stack with the aperture stopped-down? I tried adding a limiter immediately behind the rearmost lens element, but ran into aberrations (mostly astigmatism I think). This probably doesn't affect out-of-focus areas much. How close is your aperture to the rear of the lens? Oh, ...
by PanoGuy
Sat Jul 30, 2011 2:13 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Getting caterpillars to hold still
Replies: 2
Views: 1204

Getting caterpillars to hold still

Can anyone suggest a technique to make caterpillars hold still? I'm trying to photograph some polyphemus (Antheraea Polyphemus) and nothing I've tried will make them stop moving long enough to focus, let alone stack. I have tried leaving them in the dark, in the fridge for hours, etc... but as soon ...
by PanoGuy
Thu Jul 28, 2011 2:27 pm
Forum: Equipment Discussions
Topic: Monitors for photography
Replies: 12
Views: 5799

Re: Monitors for photography

The TN ones are apparently often only 6 bits per component (64 shades instead of 256 shades)... It's worth mentioning that most of the new e-IPS displays are 6-bit as well, but still retain better viewing angles than TN. The Dell U2311 and U2412 are examples of this. Personally this bothers me sinc...
by PanoGuy
Sun Jun 12, 2011 11:34 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Cell phone displays
Replies: 6
Views: 5882

The lines might also be spacers between the outer glass layers that keep the liquid crystals contained, though I don't know why they would be angled in different orientations.
by PanoGuy
Sun Jun 12, 2011 10:09 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Cell phone displays
Replies: 6
Views: 5882

Thanks for linking to that website Rik, it's better at explaining that any other sites I've found so far. Yes, the E and M fields are always 90 degrees apart around the axis of propagation. What I meant is that the E and M fields may have a temporal phase difference. If you are interested in measuri...
by PanoGuy
Sun Jun 12, 2011 7:12 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Cell phone displays
Replies: 6
Views: 5882

The color shift exhibited when rotating the linear polarizer in front of the HTC Droid means the display is likely emitting elliptically polarized light. For the benefit of anyone curious: All photons have a polarization based on the phase difference between the oscillating electric and magnetic fie...
by PanoGuy
Wed Jun 30, 2010 6:39 pm
Forum: Equipment Discussions
Topic: OM bellows slipping
Replies: 9
Views: 1997

Charles,

Is this where your shims are placed?
Image

There is not much of a gap in this area, but even when tightened down there seems to be very little pressure against the rail.

Also, how did you attach your shims?
by PanoGuy
Sat Jun 26, 2010 7:16 pm
Forum: Equipment Discussions
Topic: OM bellows slipping
Replies: 9
Views: 1997

Thanks for the link Craig. The nylon pieces don't seem to be too far out of shape, it's just that they don't grip the rail well enough.
by PanoGuy
Sat Jun 26, 2010 3:24 pm
Forum: Equipment Discussions
Topic: OM bellows slipping
Replies: 9
Views: 1997

The nylon is definitely bent as in Rik's link, but not to that extreme. Adding a piece of paper between the nylon and rail improves things, though not quite as much as I would like. Only a single piece of paper will fit currently, so I may try to set something up that will expand the nylon back into...