So, I made my own version of the Pringle Pack extension Tube, and had a quick test run with it this afternoon (it's far too hot here in Perth to stay outside for longer than 5 minutes while I'm on holidays )
First impressions:
1) I need a focus aid light, it gets real dark real quick
2) There is such a minute DOF that even the smallest bugs I found did not fit inside it
3) I might be better off getting auto tubes for my proper macro lens.
4) I forgot how hard focusing like this was.
5) The detail just doesn't seem to be there, because of the drastically reduced amount of the lens being used.
Statitica wrote:
The detail just doesn't seem to be there, because of the drastically reduced amount of the lens being used.
The central part of the lens is usually better than the outer part.
You don't say which lens you used or whether you reversed it.
That last pic has come up better.
I have just started using a head-torch. I strap it around the flash so that it is constantly shining on my subject. Makes viewing the subject easier and provides a bit more light for exposure.
I have a cheapie LED on a flexible neck from China strapped to the snoot, great in low light and darkness for focus assist.
I am surprised you are getting any dof at f2.8 - though you must have got it right on the eyes of the beetle. If you are using flash you can easily go up to f18, as long as the surrounds allow for a colourful frame - avoiding the black BG, and keep the SS up.
Don't know what advantage blackening the inner tube would give? For sharper images you might try lining the tube with foil to minimise the loss of light so the flash pulse is shortest. But you still won't get much at f2.8 - unless the exif is wrong and it is smaller as looks in last pic.
Harold, I would love to see what Topaz can do - my trial has run out... I'll send you a PM
Paul, I have done that. It's not one of the steps in the "how to" but is mentioned in the video.
Mark - If you keep the tube in it's original state (lined with foil), the light will bounce around inside it, and produce unwanted reflections. That's why you need it to be black, and also why you can't see a whole lot while peering through it. The f/2.8 is incorrect. There is no electronic connection, so the camera is using the settings from my 135 f/2.8 Ai lens.
Unwanted reflections? The whole point of using a snoot is to deliver the light to the object with minimal loss. Black absorbs light, however little in this case, and minimizes the light arriving at the diffusing material. Light bouncing inside a reflective tube won't cause unwanted reflections, it will ensure the light is more evenly distributed and hits the diffusion uniformly, assuming you make account of any strong 'beams' - every snoot (and flash) has it's peculiarities. Crinkling the foil helps.
You want sharper images? The closer you get the diffused light to the object without any loss (or absorption) the sharper they will be. It comes down to the flash pulse duration, and a reflective surface won't slow it down.
Google 'black absorbs light' and you might understand better. But go with black if you believe that is best.
Statitica wrote:
Thanks all, for stopping and commenting.
Harold, I would love to see what Topaz can do - my trial has run out... I'll send you a PM
Paul, I have done that. It's not one of the steps in the "how to" but is mentioned in the video.
Mark - If you keep the tube in it's original state (lined with foil), the light will bounce around inside it, and produce unwanted reflections. That's why you need it to be black, and also why you can't see a whole lot while peering through it. The f/2.8 is incorrect. There is no electronic connection, so the camera is using the settings from my 135 f/2.8 Ai lens....Show more →
I'm well aware that black absorbs light, and that is exactly what I want it to do.
I'm not aware of any diagrams that will help in explaining, so I'll do my best:
Essentially, the technique used here is a form of print magnification, we are projecting an image much larger than the sensor and only capturing the very center of it. Because the projected image is much larger than the sensor it will hit the side of the extension tube, and either bounce around the inside (if the inside is reflective) and produce unwanted effects, or be eliminated by a matte black finish. It is the same reason that shop bought tubes are black on the inside (and the set I had also had ripples, to counter it even more).
)
I'll send you a PM
