Dwarf 2 Tips & Tricks

I’ve been using my DWARF II (Dwarf 2) smart telescope for a few months now and feel like I mostly know what I’m doing. Here are common questions I see on the user’s forum with my answers.

What’s the first thing I should do?

Remove the plastic film that protects both the cameras in shipping, the image quality is better that way. Then put it on to charge before nightfall.

Best first target?

If you are in the Northern Hemisphere, I recommend the M31 Andromeda Galaxy or M42 the Orion Nebula as your first “target”. (Use a phone app such as SkySafari or SkyView to confirm you have a clear view to your target first…the Dwarf app doesn’t really do a good job of letting you know what is currently visible in the sky.)

Both of these targets are relatively large and bright, so you should be able to image something even in city glow. Here is what my Dwarf was able to do all on it’s own, without any post processing (click image for full size):

Spiral galaxy Andromeda in a starfield

M31 Andromeda Galaxy, 198 stacked shots, 10 sec exposures, gain 40

astronomy photo of the M42 Orion Nebula in front of a star field

M42 Orion Nebula – 47 stacked shots, 15 second exposures, gain 50

Astro-mode Calibration

For plate solving / calibration to work, the DWARF needs to be able to see a good number of stars in sharp focus. You should check/set the telephoto settings (try 1 second exposure and a gain number that leaves the background still mostly dark, but shows stars well) and then make sure the stars are small dots [using the [+][-] focus buttons, and/or a Bahtinov mask if you like to be super precise….]

NOTE: You MUST remove all filters before using the calibration procedure, as it turns the Dwarf’s tube all the way to the “zeroed” position facing down, inside the body of the telescope, and the filter holder would prevent this motion.

Then, pick a “good” starting position. When the Dwarf does it’s calibration, it zero’s out the two axis (hitting the end stops) and then navigates back to ALMOST where you had it set up at. (the place you set it up at is image number 2, it takes one image 5-10 degrees to the left, and a 3rd image 5-10 degrees to the right. If all three images get enough stars to plate solve successfully, the calibration is done. However, if ANY of the images don’t work (trees, clouds, not enough stars) it will keep trying to take more images as it moves to the right (4,5,6,7,8, up to 9 total).
So, when you pick a starting position, make sure it has stars, and then scroll the dwarf to the left and the right to make sure both adjacent positions also have good views of stars. (Favor more stars to the right after that, as it never goes left more than 1 image from the starting position).
When it does it’s plate solving, you should see “streaks” of stars while it is moving, and at least one image with dots for stars for each of the 1,2,3 plate solving attempts. If you can’t see star streaks when moving or dots when shooting, the exposure time or gain or focus is wrong.
Also, very rarely I have had it “calibrate successfully” but STILL not have the right calibration (early in the evening when you don’t have many stars….it finds a solution that is under-constrained / wrong but still thinks it knows where it is….GOTO the moon or a known object to test to make sure the calibration worked correctly before depending upon it. [or at least watch the first few stacked images to make sure the object you are imaging actually appears in it before walking away…]

 

Telephoto aiming rectangle mis-calibration

Because the telephoto lens and the wide angle lens are separated by 4 inches (have parallax) the area inside the rectangle in the wide angle view may or may not correspond to the field of view of the telephoto lens, depending upon the distance to your target.

To fix this, have the wide angle lens view be large (with the telephoto view in the smaller picture-in-picture mode). Then, you can press and hold your finger on the rectangle, and drag to move it around the wide angle view.  [I suggest you use the joystick to aim the telephoto view at something that is distinctive in the wide angle view, such as the top of a utility post, or recognizable star.]

This calibration should be “good” for objects of the same distance, but if you calibrate it with a close up object, it won’t match up for “infinite” field of view objects like stars.

MicroSD card “upside-down” orientation

The micro-sd card orientation is “upside down” from what you might expect it to be. Pay very special attention to the icon of the SD card and which way the small cutout on the card is facing when you insert it.

Rubber Micro SD card cover not fitting

If you pull out the rubber cover for the Micro SD card, you will find that it is attached to the Dwarf 2 with a thin cylindrical piece of rubber (attachment string) that comes out of a hole.  If you pull it out too hard, the cylindrical rubber bit may not want to go back into the hole, and the rubber plug may not re-insert correctly, which will block the rotation of the telescope tube when the Dwarf tries to calibrate.  To fix this, you have to carefully push the cylinder of rubber back into the hole, either by using a pair of tweezers, or by carefully pushing using the rubber plug near the cylinder. Some careful maneuvering should get it to slide back into the hole.  Once the cylinder is sliding freely back into the hole, you will be able to re-insert the micro SD card cover.

Polar or Equatorial or EQ alignment

The Dwarf 2 is designed to be mounted on the level, and its two motors act as an Altitude / Azimuth  (Alt/Az or pan/tilt) head. [The entire telescope rotates around the small base to provide Azimuth control, and the telescope tube rotates to provide Altitude control.]

It works fine in this configuration, and it uses it’s alt/az drive to track the current object of interest. But if you are taking a large number of images, due to the rotation of the Earth, the subsequent images are slightly rotated from the first image, even if the target stays in the center of the frame. This is called “Frame Rotation” and results in not having a full set of images for the outside edges of your image stack. [And requires any software stacking solution to apply a corresponding “anti-rotation”.]

You can mostly resolve this issue by mounting the Dwarf2 telescope with the axis of the base (azimuth axis) pointing in the same direction as the Earth’s axis of rotation. In the northern hemisphere, the easy way to do this is to align the Dwarf 2 with Polaris (the north star). This can be done with a tripod head that tilts at least the number of degrees of latitude of your location.  [There are several 3D printed aiming devices to help you, or you can just tape a drinking straw to the side of the Dwarf.]  If you want to know how to do this, I recommend this video: https://www.youtube.com/watch?v=X9rIk6skTU8

The questions are then….but will the DWARF work correctly in this “non-level” configuration? Will this hurt my Dwarf, or void the warranty?

Many people, including myself, are using the DWARF 2 in polar alignment successfully, so it does work and helps to reduce field rotation. So far I have not heard of any reports of a DWARF 2 failing because it was used in polar alignment, or of DwarfLabs denying a valid warranty claim due to usage in polar alignment.

However, you should know that early models of the DWARF 2 had an issue where the base plate could break off of the base. As the base plate is where the tripod nut is mounted, this could cause the entire rest of the telescope to fall to its doom.  [Dwarf Labs has published a technical note explaining how to fix this yourself if you have one of the early models.] This is due to a design flaw (the plastic that the base plate screwed into was not strong enough for the potential forces).  The factory has “fixed” this issue by using a glue to adhere the base plate to the bottom of the Dwarf as part of the assembly process.  However, I am still suspicious of the overall strength of the tripod nut and base plate, so I use a 3D printed “support bracket” with my Dwarf. It is called the “Dwarf 2 Base Plate Saver“. With this bracket, which distributes the load around the entire base of the Dwarf, I do not worry about mounting it in polar alignment.

The azimuth motor has worked perfectly fine for me, even with my Dwarf at a 28.5 degree tilt. As the weight is nicely balanced, I expect it would work very well, even with the dwarf at a much more inclined angle, so motor strength does not appear to be an issue.   There is a potential issue of the axis bearings not being designed for off-level operation, but so far I have not noticed any issues that I can attribute to non-level mounting.

Post Processing Software for Linux

If you want to spend money and get the best result, Pix Insight  (and related plugins that cost more money) is the way to go. (There are a few other paid software that only work on Windows, but at least Pix Insight is cross platform.)

I have not spent any money, and am using the Open Source SIRIL software instead.
There are a lot of videos about how to use SIRIL on YouTube…but this one is Dwarf 2 specific and also shows off Pix Insight.

Both pieces of software have a steep learning curve, but post-processing off of the DWARF can improve your final result significantly.  For example, here are my results post-processing data from the two example images above using SIRIL (click for full size):

 

Dwarf II Astrophotography filter head to head comparison: SVBONY vs DWARF UHC, CLS, No Filter

Last night I imaged the Leo Triplet using 3 different filters (and a no-filter control shot) using my Dwarf II (Dwarf 2) telescope’s built in stacking algorithm. Each session had 80 images, 10 seconds exposure, 80 gain, with IR pass enabled. The only difference was the time of night (about 15 minutes between shots) and the filter.  I’m in a Bortle 7 light pollution situation.

The Leo Triplet (a.k.a. the M66 Group) consists of NGC 3628 (to the top of the image, which is North), and M65 (bottom right) and M66 (bottom left)

This is what the DWARF II achieves on it’s own (without any post processing) with no filter:Dwarf 2 shot of the Leo Triplet without a filter

And this is using the DWARF UHC (Ultra High Contrast) filter:
Shot of the Leo Triplet using the DWARF UHC filter.
(Not all that different really…..but the background is a bit less noisy)

Here is using the SVBONY UHC filter:
Leo Triplet shot with the SVBONY UHC filter
(The stars appear to be slightly smaller, but so are the triplet galaxies, and the background noise is reduced).

And since I had the SVBONY CLS (City Light Suppression) filter, I also tested it out:
Leo Triplet shot with the SVBONY CLS filter

My takeaway from the four images above (which look very similar, with only subtle differences) is that the SVBONY UHC and the DWARF UHC appear to have relatively similar performance. Also, the Dwarf II’s built in stacking software doesn’t do a super great job illustrating any difference between these filters.

Perhaps my target is the problem, in that UHC/CLS filters may not help much when imaging galaxies. The next time I get clear skys I will try to repeat the test using a nebula.

If you want to try your own post processing, I’ve posted the Raw Data zip file here.

Aftermarket Glowforge Hinge bracket installation

I’ve had issues with the front handle and rear hinges separating from the glass lid of two different Glowforge units.  After repairing one side of the rear hinge that was separating I decided to try out an aftermarket hinge bracket designed to get a better connection between the glass lid and the two hinges.

I paid $160 with shipping to an eBay seller for item number 175473691329 “New GLOWFORGE Aftermarket LID Hinge Repair Bracket, All Metal Construction” which has a U-shaped channel to surround the rear edge of the glass lid.  It was a bolt on (and silicon sealant glue) procedure, and the hardest part was unsticking the double sided adhesive used to hold the glowforge lid ribbon cable in place.  [I ended up using dental floss to saw through the sealant behind the cable….when I replaced it I just used electrical tape to hold the cable in place.] I also had to spend some quality time removing the epoxy that I had used to initially repair it for a few months.

The procedure went smoothly, and the lid appears to be working (and sticking) well, although only time will tell for sure how much better this bracket is compared to the original one.

Anova Precision Handheld Vacuum Sealer – Works with FoodSaver Jar sealer accessories

Anova handheld vacuum sealer on top of a foodsaver jar sealer

We have a FoodSaver vacuum sealer that we only use for the accessory port with the mason / canning jar lid sealer accessories. [These allow you to vacuum seal items inside a canning jar.]

I purchased an Anova handheld vacuum sealer (that is made to work with re-usable ziplock style vacuum bags) and verified that it fits well enough onto the top of the FoodSaver jar sealer accessories to vacuum seal jars without the use of the (rather large FoodSaver).  This will allow me to get rid of the foodsaver, and only store the mason jar lid accessories with the Anova handheld vacuum pump.

I confirmed that the Anova unit could pull 14 inHg on the initial vacuum, and if you pushed the button a second time, it would get the vacuum down to 15 inHg. [The plug-in full sized FoodSaver unit drew down to 16 inHg, so slightly more vacuum, but not enough more to justify the space it takes up.]

 

 

Amazon affiliate links:

ABQ Sunport Wifi doesn’t work with Ubuntu Linux – workaround

I have a Lenovo X1 laptop with Ubuntu 22.04 on it, and it will not connect correctly to the Albuquerque (ABQ) airport free WiFi.  I’ve tried lots of things to debug/diagnose this, and nothing got it to work successfully.

However, my android phone does connect successfully via Wifi, so I was able to turn on USB Tethering on the phone and access the wifi via a USB cable and my android phone.

How to limit charging to 80% on a later model year (2014+) Nissan Leaf

Early (2011-2013) United States Nissan Leaf’s had a “limit charging to 80%” feature in the dash.  Nissan removed this feature from US cars after the EPA ruled that if the feature remained, they had to report a lower battery range because on average the car would not be fully charged when it left. [This ruling was incorrect in my opinion…but Nissan removed the feature so that they could advertise the EPA range based upon a 100% charge of the battery.]

I, and many other people, still like to limit charging to only 80% of the battery total capacity in an effort to extend the life of our EV batteries. [This extra effort may or may not be worth the trouble, and many people advise to just charge to 100% and not worry about your battery health, especially for 2016+ vehicles which have a longer battery warranty. But I like to limit charging of Lithium Ion batteries to 80% if I don’t need the extra range.]

If you wanted to only charge your Nissan Leaf to 80% (unless you need extra range for longer trips) on a regular basis, how can you do it on later model year vehicles?

There are three options that I know of:

1. The only way to get a similar effect (keeping the car below 80% SOC most of the time) using only  inbuilt features (i.e. without spending extra money) is to set up the charging timer to charge your vehicle right before you leave. This only works well if you have a regular departure time each day (e.g. for a static work schedule). Then, when you plug in the car, it will not charge until a few hours before your scheduled departure time, aiming to reach 100% about 30 minutes before you depart. This means that the time the battery sits at 100% is minimized. [If you are clever, you can lie about your departure time so that it is reaching 80% about the time you actually leave…]

The downside is that your vehicle is not “ready to go” if you need to leave for an unplanned trip before your regularly schedule departure time, and if you want to charge any other time you have to remember to disable the charging timer so that it will actually charge when you plug in. [My 2015 leaf has an easy to use button for disabling the charge timer…]
Nissan Leaf charging timer disable / off button

So this can be made to work if you have a regular schedule, but it can also be annoying.

2. You can “mimic” the “charge only to 80%” feature by using a Smart / connected EVSE that has a charge limiter built in. For example, I have a JuiceBox, and when I plug in my 2015 leaf, I use the phone app to set the “plugged in percentage” and “stop percentage” (which I just leave at 80%) and it estimates the amount of power needed and will shut off charging after that amount is used. This requires that you pay money for a smart EVSE…but if you haven’t already purchased an EVSE, getting a “smart” or “connected” one with a similar feature will probably only add 1-2 hundred dollars to the purchase price.

Juice Box Pro 40 front faceplate, original silver model from e-motor-works

3. There is also a 3rd party add-on box you can install in your vehicle called Open Vehicle Monitoring System (hardware device) that would allow you to set a charge % limit and also do things like pre-heat in the winter remotely, and has a lot of other logging features…. but it costs $260 (and if you want to be able to use it on a cellular network away from your home/work WiFi networks or the bluetooth range of your phone, you need to include a SIM card with data capabilities which will also probably have a monthly fee)

Open Vehicle Management System Screenshots

Because I already had a JuiceBox, I use method 2…but if I already had a non-smart EVSE, I would probably go with the OVMS route, as it adds other features to the car.
[Especially since the Nissan Connect system in my 2015 leaf no longer works as it used an older 2G cellular service that has since been retired.]  If you have a brand new Nissan Leaf, it probably includes the Nissan Connect service, at least for the first three year of car ownership.

Sphero 2.0 battery replacement

The original batteries in my (8-10 year old) Sphero 2.0 died.

bloating lipo lithium batteries
Once I got the sphere open and removed them, it was clear that they had “bloated”.
They are marked 702035 (7mm thick, 20mm wide, and 35mm long).  However, I don’t recommend buying 702035 batteries to replace them, as the opening they need to go into is closer to 30 or 32mm in length. If I had to do it again, I’d order these 702030 batteries instead.
Continue reading

Reverse Bifocal Trick for Prescription Crafting Glasses


I need optical magnification to work on small crafting projects. However, I also wear prescription lenses, so used a headband based magnifier that I could wear with my glasses. It worked fine, but I didn’t like having to wear two different things on my head, and the forehead mount was a little uncomfortable.

So, I’ve come up with a trick that allows you to order prescription glasses that include a magnifying inset lens. For those of you who wear bifocals…yes, I’m talking about bifocals. By turning the NV (Near Vision) field of a bifocal prescription as high as you can get it, you can get a magnifying bifocal insert of 1.87 X or greater.

The formula that relates optical magnification to dipolars is:

Magnification = (Dipolar / 4) + 1

So with the maximum +3.5 dipolar Near Vision (NV) setting allowed by Zenni Optical, I’m able to get prescription glasses that include a 1.87X magnification inset.

Of course, they are down near the bottom of the field of vision, which works OK for reading in your lap, but not as great if you paint with your elbows on the table like I do.


To move the magnifying areas from the bottom of the glasses to the top, you need to rotate the lenses 180 degrees, AND you need to swap the right and left lens. [So that the bifocal inserts are on the insides, and not moved to the outside of the lens…]

This means that when you ORDER the glasses you must REVERSE or SWAP the OS and OD (Left/Right eye) prescription lines!  Other than swapping for left/right eye, the cylinder and axis numbers don’t need to be changed, as the 180 degree rotation is a perfect no-operation for them!





You also need to order a lens and frame style that is perfectly symmetrical, so that you can fit the lenses back into the frames after you rotate and swap them. I recommend metal frames held together with screws, or rimless models where the lenses bolt directly to the frame pieces. (But watch the mounting holes for symmetry!) Round lenses are usually your best bet, but you could make it work with some of the hex or octagonal lens styles.

I used Rimless Glasses 3229415 from Zenni Optical. If you use my $5 “Refer a friend” link, you get $5 off, and I get $5 towards my next non-standard experimentation with optics (because this wasn’t my first order from Zenni…)

5$ off link: https://bit.ly/3LLPZCX

Alternatively, if you don’t want to hack your glasses, I recommend the headband based magnifier with light in this amazon affiliate link:
https://amzn.to/3xTWRIV

Total cost? This set of glasses only cost me $54 (now that I know what I’m doing) but I did waste another $50 for a different set of bifocals before realizing that the standard bifocal inset area was too low for my needs, and that I’d have to modify the prescription by swapping the left/right eye so that I could rotate and swap the lenses.

Here is a video about the procedure: