In two earlier posts titled “Lens adapter with filter drawer” and “Lens adapters: flange-to-flange distance” I discussed how crucial it is to achieve the exact effective flange-to-flange distance when dealing with adapted objectives with a very short focal distance. I also described how I shimmed an adapter to achieve this. Recently I had an opportunity to use the Sigma 4.5mm 1:2.8 circular fisheye objective in Nikon AF mount adapted to …
I here describe my experience with the DEO-TECH OWL EF/MFT lens adapter. The adapter is available mainly through astronomy web stores and seems to be currently distributed by Optolong. It is also available on special order at B&H photo video and possibly other large shops. Development of the adapter was initially funded through Kickstart crowd funding.
How far can we go, with off-the-shelf equipment One question which I have been pondering for some time is: do I need to have a digital camera converted to full-spectrum for UVA photography? and are there any modern objectives that are good accidental UVA-objectives? This is not a question of cost alone. Although a converted camera can be used for VIS photography, obtaining good colour reproduction requires effort. A suitable …
Using the E-M1 converted to full spectrum with the Pinhole Pro objectives is possible. Using a 58 mm NIR filter (Hoya R72) attached to the front of the 11 mm Pinhole Pro S11 worked fine, with no increase in vignetting. Using the StraightEdgeU 52 mm or Baader U-filter 2″ with a step-down ring blocked the corners of the image completely. The original 26 mm Pinhole Pro suffers a lot less …
Introduction Pinholes need to be very small to provide a useful image. Consequently the corresponding f-values are small, in most cases f:100 or smaller. This results in either very long exposures, or requires the use of very high ISO values. As we will see in the example images this is less of a problem than what could be expected because as the resolution of the pinhole is low, the images …
I have been testing some objectives for their UV transmission using LEDs as sources of radiation. I developed a protocol for such tests. Although used in this example to measure the spectral sensitivity of a camera sensor, the protocol can be easily adapted for the measurements of biological action spectra.
An on-going Kickstarter campaign offers sophisticated pinholes for digital cameras in an assortment of different lens mounts.
Last week I was asked about what objective I use when photographing live insects in the field. I do not always use the same objective, so I will describe the two I most frequently use. Neither do I use what would be the most suitable or state-of-the-art optics.
