Notes on OM System OM-1 digital camera (DRAFT)

Quite a lot has been already written in the internet about the OM System’s OM-1 camera, but I write down here some notes comparing it to the E-M1 Mk II and highlighting some use cases. I share this notes in case someone else finds them useful, although they are mostly intended for myself. Among the things frequently mentioned is a lack of improvement in image quality between old and new image sensors (e.g., OM system OM-1 vs OM-5 – The 10 Main Differences). This is one example of where my own experience differs drastically from the quick and dirty tests…

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Broad band VIS+NIR LEDs

Broadbands LED based on a blue LED and “phosphors” have appeared in the market. One example is type SMB1N-BB450 from Roithner LaserTechnik (Vienna, Austria). The primary LED has a peak of emission at 450 nm and the spectrum as a whole covers the range 400 nm to 1000 nm. Except for the prominent blue peak the spectrum is rather flat, making it useful light source for VIS and specially NIR imaging and spectrometry. This LED type seems useful for photography as well as for its intended use is spectrometry. Emission is rather weak and efficiency rather low, emitting 0.3W of…

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NIR-pass filters

All the near-infrared (NIR) long-pass filters described in this post are absorptive glass filters and sold for special photography effects. All modern photography digital cameras have internal UVIR-cut filters. Use of these filters requires special film, special digital cameras or modified DSLR or DML cameras. Some filters can be used with unmodified digital cameras with very long exposure times. Few normal camera objectives are designed to work well in NIR. Two problems are common: 1) focus shift which needs special attention when focusing is done in visible light (e.g. not using an EVF or live-view from the camera sensor, 2)…

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Lens adapters: flange-to-flange distance

Today I received a “K&F Canon EOS-M4/3 PRO” adapter (bought from https://www.kentfaith.com/). This is a new design advertised as being of high precision. I was specially interested as this is one of the very few or maybe the only series of relatively low cost adapters with a non-reflective black interior finish. This is is important to prevent reflections that otherwise degrade image contrast or create flare and ghost images. Please see Black anodised aluminium in IR and Commlite products: how I wasted my money.

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Lens adapter with filter drawer

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.

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UV-cut filters

As described in the post UVIR-cut filters both absorptive filters and interference filters are sold as UV-blocking filters. All modern photography digital cameras have internal UVIR-cut filters and most modern objectives transmit little UV-radiation. There are some exceptions, most if not all Olympus cameras are sensitive to long-wave UV-A radiation and a few modern objectives also transmit long UV-A radiation. Many filters sold as UV-filters do not differ from those sold as clear protection filters enough to matter. However, a few UV-filters do absorb in the whole UV-band and even into the visible violet band. Their effect might make a…

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UVIR-cut filters

Filters can block radiation either by reflection or absorption. Absorptive filters are usually made of glass containing various metal ions while cheaper plastic filters tend to be coloured with organic dyes. There is a third type of absorptive filter, which are rare nowadays that consist of a coloured gelatine layer in-between two glass sheets. Most high-quality absorptive filters sold for photographic use are made of solid glass and absorptive. In the case of square filters plastic is more common than for smaller circular filters. The current perfected version of the gelatine-between glass filters is Tiffen’s “core technology”. With absorptive filters…

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Godox AD200 flash for UV, VIS and IR photography

[Updated 2019-07-18] Godox sells a medium-power flash called AD200 with interchangeable heads and several accessories like light modifiers and remote wireless triggers with TTL exposure metering and high speed synchronization capabilities. This gives a lot of flexibility in its use. After a few separate purchases I now own the AD200 and the H200, H200J and H200R heads, an Xpro-O TTL Wireless Flash Trigger, and several light modifiers, all of them branded Godox. (The same flash and accessories are also available under other brand names.)

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