DaveSw

I have to add a plug for Fuji's Acros B/W film. Though rated at ISO 100 it is extremely useful for long exposures. It has minimal reciprocity failure. In a previous life (architectural photography) I used it extensively for dusk and night shots with exposures running into tens of minutes. Very fine grain and a high dynamic range when used with compensating and semi-compensating developers. (Pyrocat-HD with extended semi-stand development was my favourite.) I never used it for "astro" photography during that period (and I sold all my camera equipment to pay for astro-equipment after retirement.) Back in 1976 I did some film based astrophotography but with 4x5 inch glass plates and Kodak's astronomical emulsions (103-aF, IIIaJ, etc.) and a telescope with a balky drive system. No useful images (other than some spectra). Gas hypering was certainly coming into vogue at that time with much discussion in the literature (e.g. AAS Photo-Bulletin). I never had the opportunity to try it but did experiment with some developers compounded for astronomical use (MWP-1, MVP-2 come to mind) Based on previous experiences I'm very happy with the current digital sensors, but applaud those who still exploring what can be achieved with traditional silver-based emulsions.

Looking forward to learning more on this...

I do not know if it works with NINA as I'm a Mac user. From what I've read, NINA does have the ability to control the Flip-Flat so it might be safe to assume it can control this device too if NINA can be configured to use the older "Flat Man" device (w/o the flap). The device type is defined in the protodol. As I am building it, the system is a mashup of hardware and software drawn from a number of sources. The hardware comprises an Arduino Nano, a few resistors, an N channel logic level MOSFET, suitable power supplies, and the light panel I have a 12V source for the LED panel and use a LM7808 (8V linear regulator) for the Arduino's Vin. A 12V to 5V converter could be used but I have the linear regulator on hand. I don't have a schematic drawn up yet but sites such as https://www.blackwaterskies.co.uk/2020/03/cheap-diy-remote-controlled-flat-panel/ show a similar design. After making the suitable voltages available, the appropriate Arduino PWM pin is connected to the gate of the MOSFET via a current limiting resistor (along with a 10Kohm or so resistor to ground). I include a Schottky protection diode across the MOSFET source and drain as well. Commands come and go via the Arduino USB port. The software emulates the Anitak generic command protocol as defined here: https://www.optecinc.com/astronomy/catalog/alnitak/resources/Alnitak_GenericCommandsR4.pdf I started with Jared Wellman's software (see github.com) and modified it to use the version 4 of the Alnitak commands (uses letter O rather than numeral 0 in command sequences). I later came across another version of software by Peter of gluonfield.com (http://gluonfield.com/spacelike/content/astrophotography-flats-panel) and adapted it instead. (changed his command message terminators back to match the original Alnitak specs.) I liked the gluonfield software as it allows for altering the PWM frequency to avoid any refresh related issues. Currently I am designing the light panel and am considering a number of designs. A flat box like those described in this thread is the leading contender at this time. If you want a copy of my current software let me know and I can send it to you. Dave

I've come late to this post, but as I am currently in the process of designing/building a flat panel form my WO GT-71, I'm very happy I found this post. Thanks for these designs Bill. I have a circuit using and Arduino to vary the light intensity (for various filters) that will be controlled by the Kstars/Ekos/Indi software I use.

The days of Cibachrome printing and unsharp masking of slides. I don't really miss that part. (the youth though... that's another thing) ps: nice cats

I wondered about the brightness being high. Until now I've been using my iPad screen turned down to 1/4 brightness or so with two sheets of diffusion material (Mylar based Kodak product from my horde of darkroom stuff - '70s vintage) to get exposure in the 1-2 second range on my GT-71 refractor. I am currently working towards an Arduino controlled LED source I can use with Kstars/Ekos/Indi for semi-automated flats exposure. So far I've "borrowed" Arduino code from several sources and can control a test LED with Ekos. Ekos wasn't handling the flat panel properly (using indi driver FlipMan) but the issue is currently being actively sorted). The next step is the actual LED panel/scope attachment mechanism design and build. I am leaning towards a circular/cylindrical design rather than a panel design. (interesting information in this article: https://www.ing.iac.es//astronomy/observing/manuals/ps/tech_notes/tn108.pdf

Very nicely done. A good way to spend part of a sunny Saturday on the Island.

Yes, that's the one. Thanks for your kind offer, I look forward to hearing how it turns out. (not sure if it's important but I working with a version 4 Pi) Dave

Mention was made by fozzybear that the Linux version of the Arduino Dew Controller software runs on Astroberry/Stellarmate (Rasp. Pi). I was wondering if anybody has appropriately compiled the ESP32 version yet to run on the Pi? (I'm not from the world of software development so have minimal familiarity of what's required to properly compile the Linux version for the Pi. But, that said, I can usually follow directions if someone could point me in the right direction. I'm retired with time to "experiment" [not what my wife would term it]) Dave

Not sure if anybody is still following this thread or not... I decided to build Robert's ESP32 controller instead as I had the appropriate ESP32 sitting in the parts box unused. While awaiting the final few parts I'm working on designing the component layout for the box enclosure. I'm using a box from Amazon rather than a 3D printed one like JamesF showed at the start of this thread. In light of this I was wonder if anybody has pictures of their completed units they can post? I do have a few of the ESP32 Rev06 boards available if anyone is interested. I am in Canada (on the left, wet coast). Keep this in mind - it turned out to be cheaper for me to order boards than pay the shipping/fees for someone to send me a single board from Europe. Dave

Peter, I too would love to see a picture of the wedge plate repair you mention. I recall in the past seeing something on a German site, but now that I'm serious about dealing with my adjustment difficulties I cannot find it again. (and I thought I'd saved it...)

Bruitie, did you get any feedback on this, or is it "alls well" with the assembly order you described for the various washers? Last night (1st clear one in two weeks) I had a very hard time trying to make minor adjustments to my elevation while polar aligning. (I'm at 49 degrees and a bit). Down was a non-issue but up was very hard. As a result, today I am learning what I can before I start any surgery. (and the mount is only a few months old)

Based on what I’ve learned in the past few days I am inclined to agree the best course is to ignore it. But still baffling why they would include a screw that is essentially useless...?

Looks like some of the things I've made in the past. Usually with a proto-board so the wires pull out just a little to easily when things get joggled around looking for the (whatever) you just saw and need now.

Thanks for the confirmation Craig, that's what I thought was the likely purpose. Given that it doesn't actually lock the circle down and drags on the polar axis, any suggestions as to why that might be the case. I do not want to start pulling things apart until I've "heard from the experts". So far the only images I've seen are those provided by Astro-baby's stripping/rebuilding articles. (though I don't think I've exhausted the search...)