23 replies to this topic

[Jon Rista]

I am looking to get both of my imaging setups working with SGP. I tried SGP out about two years ago, but lack of any focus capability for my Canon lens tabled it until now. I am hoping to image with both the RC and the 600mm lens, so I was looking around to see if anyone had created an ASCOM driver for EF lenses. Turns out, someone did:

 

http://www.astronomy...c,129572.0.html

 

I am wondering if anyone else has tried this? The documentation seems to be written in Russian, and this option requires an Arduino-based controller so the computer can actually interface with the lens. I am ok with building an Arduino controller, but I cannot read the documentation. (And the browser translate feature doesn't seem capable of translating a PDF. :'(). I did install the driver, and the 600mm f/4 L II is listed, so at least it is supported...if I can build the controller unit. This would be pretty awesome if it allows me to use the 600mm lens with SGP.

[Thirteen]

I can't really help you but this would be awesome.

[telfish]

https://github.com/M...slator/releases

 

Try that.

[Palomar]

Hi! My name is Sergey! I developed this controller and wrote ASCOM driver. I'm glad that someone interested in my project, and I want to help you with your lens.

 

Features (supported by driver):

• focus control;
• iris control;
• temperature measure (additional sensor required, e.g. popular DS18B20).

This device uses SPI interface. You will need microcontroller which supports SPI. My firmware is written for ATmega microcontrollers (tested on 8/8A/168/328P). You can use Arduino boards such as Uno, Nano.  Also you will need an adapter for easy connection to the lens.

 

All details about connection and using ASCOM EF Controller you can find in my PDF document, which I translated into English. If you have any questions, please write to this topic, I will try to help.

 

ascom_ef (EN).pdf

https://drive.google...iew?usp=sharing

[Jon Rista]

Thanks, Sergey! I appreciate the work you've done here. I am also very glad you translated your document. I know one member on these forums has started implementing your design. I think he has a little bit more testing to do, but it seemed the initial indoor tests worked.

I have been looking for a way to connect the pins on the lens with a slimmer connector, so I could use this with an unpowered EF adapter on the camera side of things, as I am trying to use my 600mm lens with an ASI1600 camera. So far I have not found a solution, but I think there are some options out there that might work. Waiting on testing from this other member to verify.

[bilgebay]

A very interesting topic Jon.... and thanks to Sergey for his efforts.

 

Now I have a new project for rainy days thanks to both of you

[bilgebay]

And welcome to CN Sergey!

[pfile]

i'm curious how this works - if you put in one of these shims which exposes the SPI bus, how does the lens come to focus at infinity? i know this would be a problem for most astro cameras but it would also be a problem for a regular canon body.

 

Sergey's PDF shows a number of shims which get thicker and thicker, which would seem to make the problem worse and worse. what am i missing here?

 

rob

[Jon Rista]

i'm curious how this works - if you put in one of these shims which exposes the SPI bus, how does the lens come to focus at infinity? i know this would be a problem for most astro cameras but it would also be a problem for a regular canon body.

 

Sergey's PDF shows a number of shims which get thicker and thicker, which would seem to make the problem worse and worse. what am i missing here?

 

rob

 

You are not missing anything. This is why I have not yet implemented it. I've been looking for a thin ribbon-cable like unit with the necessary electronic pinouts that I could slip between the lens and a normal EF mount to M42/M48 adapter (i.e. TSEOS-T2s), and connect to the controller, instead of the extension.

 

Futuneral has already implemented the extension version, although I think he had enough backfocus with his scope and camera to actually fit it and still achieve infinity focus. We have been looking around for the necessary pinout. He found one option that might work (I have to go digging through my PMs to find the link), but I have been focused in the ASI1600 lately so haven't gotten around to ordering and trying it out. 

 

EDIT: 

 

Here is the electrical contacts unit that Futuneral found:

 

http://www.aliexpres...0708.4.5.mFFSCm

 

I am not sure if it will actually fit without modification...I suspect some modification will be required to get it to fit with the EOS adapter I have. There may be other adapters out there that other people have PMed me about that I am interested in trying as well. It may be possible to convert a normal 10mm Canon EF extension tube with electronics to have an M42 or M48 adapter on the camera side. You could then just hack the interface in the extension tube to connect it to the Arduino controller.

 

Anyway. There are ideas and options. They just need to be explored. It's somewhere in the middle of my long list of things to do. If someone else gets there before me, more power to ya! I'm very interested in seeing if/how it works. Would be really nice to be able to control the aperture of the lens as well. 

Edited by Jon Rista, 08 June 2016 - 03:24 PM.

[pfile]

OK thanks - i guess since those things are called macro adapters they let you focus even closer to the front of the lens? so kind of the opposite of what we need to do.

 

i should look at my SBIG filter wheel cover and see if there's any way to shim in the connector you linked. i think it could be quite difficult. to be honest i've never experimented with trying to see how far away i can get my 200L from the sensor, but i do know that the extra thickness of the SBIG OAG filter wheel cover (vs the non-OAG cover) is too much. 

 

seems like perhaps a 3d printer could be useful here. 

 

rob

 

edit: ah - it's not as bad as i thought - there's just nothing behind where the contacts are. so probably the part Futuneral found would be easy to get in there... the hard part is how to secure it so that it makes good contact with the lens. i wonder if there are any glues strong enough for this purpose?

 

 

 

Edited by pfile, 08 June 2016 - 04:44 PM.

[Jon Rista]

You got it now. I haven;t thought deeply enough to figure out how to fix the part futuneral found to the EOS adapter, or whatever you end up having to use. I think it would need to be pretty darn sturdy to make sure you did not mix up the contacts, and you would want to make sure it could withstand changing torque during tracking, or if you had a heavier filter wheel and camera on the other end. One of the other potential issues is the locks on third party astro adapters and a log of 10mm extension tubes are not very reliable. The TSEOS-T2s has a very weak pin that is supposed to lock the adapter into place, much like the lens locks into the camera body. It pops out pretty easily.

[pfile]

i think if push came to shove, you could probably temporarily affix the connector in there, as long as you can put the lens on the adapter first and then remembered to never remove the lens from the front. on the other hand the mounting screws on my sbig adapter are perhaps too close to the lens to actually be able to do this.

 

by the way i looked around at various places with canon repair parts, and it looks to me like only the t5i and the 5d3 parts are appropriate. all the other ones except for the 60d seem to have separate wires (actual round wires with insulation) for the lens power, which would probably be crushed if you tried to fish them thru the interface between the adapter plate and the filter wheel. the 60d one is a little weird in that there seems to be some kind of switch or some other component in the flat ribbon cable, which splays out into multiple cables.

 

if you try to use one of the ones with the separate power wires, in the case of the SBIG setup i guess you might be able to somehow power the lens from a voltage available inside the filter wheel but that's a little risky.

 

rob

[Palomar]

Mechanical part, the most difficult and interesting case in this project.

 

Some time after experiments I made regular adapter. I used aluminum coupler 26 mm thick, made on lathe machine. On one side it has thread M42. This thickness turned out because I did not use filter wheel. I shoot with Baader 36mm Ha filter and my adapter has mounting for it. Infinity focus is achieved without problems (SBIG8300 + 200L).

 

Then I made a PCB with spring contacts (springs were taken from Chinese adapter). Also 3D printing have been used for special ring which fixes springs and prevents contact between them. Rear lens cap with cutted center has been used as bayonet mount.

 

This design has worked for a year on my remote observatory. Result is excellent, no complaints.

 

[pfile]

the replacement lens contact assembly i chose is the 5d3 part and it has... wait for it... 0.4mm pitch conductors at the end of the ribbon cable. likewise, the connectors for these things also have 0.4mm pitch pins, so you pretty much need to design your own board and use an SMT rework machine to solder the connector down. it's not even clear to me that the flex cable is long enough to make it out from underneath the sbig bayonet adapter. it may be a non-starter.

 

so now i'm starting to think one of the older connectors with the discrete power wires is a better play, but you'd never be able to get those thru the interface between the filter wheel and the lens adapter.

 

that leaves trying to route the wires out the "back", and drilling a hole in the filter wheel cover to get the wires out. seems like a pretty bad idea. and that doesn't solve the fine-pitch connector problem, which all the canon replacement parts seem to have.

 

it could be that Sergey's solution is the only clean one - forget about the filter wheel, just use some type of fixed filter and build something out of one of those macro adapters.

 

rob

[CraigShelley]

Mechanical part, the most difficult and interesting case in this project.

 

Some time after experiments I made regular adapter. I used aluminum coupler 26 mm thick, made on lathe machine. On one side it has thread M42. This thickness turned out because I did not use filter wheel. I shoot with Baader 36mm Ha filter and my adapter has mounting for it. Infinity focus is achieved without problems (SBIG8300 + 200L).

 

Then I made a PCB with spring contacts (springs were taken from Chinese adapter). Also 3D printing have been used for special ring which fixes springs and prevents contact between them. Rear lens cap with cutted center has been used as bayonet mount.

 

This design has worked for a year on my remote observatory. Result is excellent, no complaints.

 

adapter_1.JPG

adapter_2.JPG

sbig.jpg

 

Hello Sergey, It appears as though you've refined the Canon EF Focuser unit: https://astronomy.ru...,129572.40.html

 

 

 

Please update us on the current status.

[misfor]

Hi all, im building this focuser now and - one matter: can you, Sergey, update arduino sketch for use with DS18b20? i see only version with some analog sensor...

superb design, btw.

best

[Palomar]

Hello to all!

 

Sorry guys, a long time since I have not written. And now I would like to introduce you a final version of my project. Presenting Canon EF/EF-S compatible solution for external iris & focus drive. This adapter supports all lenses compatible with Canon EOS protocol (Tamron and Sigma too). You can control it by ASCOM Platform tools (Maxim DL, FocusMax, etc) or use simple desktop utility. But first things first!

 

The device looks like it's shown in the picture below.

 

 

On board. SBIG STF8300 + Canon 200L

 

 

QHY5 + Canon EF200L

 

 

Electronic parts haven't changed significantly. The device housing is made of metal (aluminum) and it surface is black anodized. Symbols are laser engraved. The powerful solid state laser is a really cool thing! The text is clear and well detailed, even small letters! The controller has 2 inputs: USB for connecting to a computer and DC IN 5V for huge lenses with large power consumption. POWER and SIGNAL LEDs is needed for user convenience. SIGNAL LED will be light on when transmitting the packet.

 

The most difficult part is a mechanical lens adapter.

I decided to make 2 types of this part: for M42 cameras with a small chip up to APS-C format and Full-Frame solution with 36x24 sensor and M54 thread interface. When designing I used the documentation from popular QHY/ZWO cameras. Back focal length of the Canon EF lens, as we know, is about 44 mm. Mechanical drawing is shown below.

 

 

Moreover, I implemented a standard filter socket on a rear side of the adapter. It was done because the full-sized filter wheel is not applicable in this assembly. There is no place for it. Bayonet parts, PCB with spring contacts, wire connection occupies a lot of space. I don't know if it's possible to make an adapter with a smaller thickness.

 

You can use round unmounted 36x2 mm filters for M42 adapter or 50x3 mm for M54 Full Frame adapter. Filters are clamped by a special lock ring. This ring has a thread with a little bit smaller diameter than the external adapter mounting thread. This way the filter can be changed at any time. Not as convenient as the filter wheel, but it's better than nothing.

 

 

Assembly diagramm is shown below. You can see both types of adapter. Simple system that can be used with a wide range of cameras and lenses. No additional external parts required.

 

 

To be continued!

[FiremanDan]

Hello to all!

 

Sorry guys, a long time since I have not written. And now I would like to introduce you a final version of my project. Presenting Canon EF/EF-S compatible solution for external iris & focus drive. This adapter supports all lenses compatible with Canon EOS protocol (Tamron and Sigma too). You can control it by ASCOM Platform tools (Maxim DL, FocusMax, etc) or use simple desktop utility. But first things first!

 

The device looks like it's shown in the picture below.

 

 

On board. SBIG STF8300 + Canon 200L

 

 

QHY5 + Canon EF200L

 

 

Electronic parts haven't changed significantly. The device housing is made of metal (aluminum) and it surface is black anodized. Symbols are laser engraved. The powerful solid state laser is a really cool thing! The text is clear and well detailed, even small letters! The controller has 2 inputs: USB for connecting to a computer and DC IN 5V for huge lenses with large power consumption. POWER and SIGNAL LEDs is needed for user convenience. SIGNAL LED will be light on when transmitting the packet.

 

The most difficult part is a mechanical lens adapter.

I decided to make 2 types of this part: for M42 cameras with a small chip up to APS-C format and Full-Frame solution with 36x24 sensor and M54 thread interface. When designing I used the documentation from popular QHY/ZWO cameras. Back focal length of the Canon EF lens, as we know, is about 44 mm. Mechanical drawing is shown below.

 

 

Moreover, I implemented a standard filter socket on a rear side of the adapter. It was done because the full-sized filter wheel is not applicable in this assembly. There is no place for it. Bayonet parts, PCB with spring contacts, wire connection occupies a lot of space. I don't know if it's possible to make an adapter with a smaller thickness.

 

You can use round unmounted 36x2 mm filters for M42 adapter or 50x3 mm for M54 Full Frame adapter. Filters are clamped by a special lock ring. This ring has a thread with a little bit smaller diameter than the external adapter mounting thread. This way the filter can be changed at any time. Not as convenient as the filter wheel, but it's better than nothing.

 

 

Assembly diagramm is shown below. You can see both types of adapter. Simple system that can be used with a wide range of cameras and lenses. No additional external parts required.

 

 

To be continued!

Wow, that looks really cool! 

[dciobota]

That does look very interesting.  Any estimate on price and availability?

[Palomar]

Two types of adapter (M54 and M42) are presented below. Full frame adapter has a square window slightly larger than standard 36x24 mm chip. Clear aperture of the small adapter is 34 mm. Both adapters can be mounted on a tripod (1/4" thread).

 

 

 

 

Electrical contact is provided by gold plated spring contacts. This is a good solution, Canon SLR cameras have the same design for electrical connection with the lens. But these contacts take up a lot of space and the adapter cannot be made very thin. Minimum thiсkness is about 16 mm (default - 26 mm for M42x0.75 adapter). Theoretically, we can get this thickness by refusing long spring contacts. But in this case the device reliability is at risk, because there will be no reliable contact with lens during data transfer. In addition, we need to connect an external wire from the controller to the PCB and pass it through a moisture-proof gland.

 

 

All parts were made on a CNC milling machine. I used 70 mm aluminum rods as a workpiece. Each part was processed from three sides. Total processing time was about an hour. Finally we got such beautiful details. I like metal working.

 

 

 

 

[Ron in Michigan]

and?

[CraigShelley]

and?

Ron, what would you like to know?

[pfile]

just FYI there is a new version of this adapter that frank has tested here:

 

https://www.cloudyni...15mm-lenses-ha/

 

rob

[ChrisWhite]

just FYI there is a new version of this adapter that frank has tested here:

 

https://www.cloudyni...15mm-lenses-ha/

 

rob

 

Mods should consider locking this thread and end with the link to the current convo that Frank started...

Edited by ChrisWhite, 01 June 2019 - 09:09 PM.