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IP/CCTV lens for RT224 camera

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#26 Relativist

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Posted 31 March 2018 - 02:30 PM

Interesting twist. So I can try out the lens that came with my Sony A5100 with an adapter like this?

https://www.back-bon...-mount-adapter/

#27 Relativist

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Posted 31 March 2018 - 02:33 PM

Nice option, question is what tripod would one use?


What I mean is, no tripod is included, so what can be used? As I understand it’s not readily a tabletop mount. That’s one of the reasons I went with Nexstar for my low low budget build. Maybe The lowest budget build is next...

#28 ccs_hello

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Posted 01 April 2018 - 10:59 AM

re: Interesting twist. So I can try out the lens that came with my Sony A5100 with an adapter like this?

 

Need E-mount version.

Also a C-mount lens has much smaller image circle size (typically type-1/3") for an APS-C sized image sensor.



#29 cmooney91

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Posted 02 April 2018 - 06:53 AM

I made a 3D printable 1.25" camera nose mount that works with a vixen clamp, or 1/4-20 tripod thread.

 

wYLmUSt.jpg

 

Files are here

 

 

I will make a Synta finder dovetail version so it can easily be piggybacked on an existing scope/mount.


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#30 cmooney91

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Posted 03 April 2018 - 09:16 AM

This lens looks like an interesting candidate.

 

$45 8-50mm F1.4 1/2 Inch C-Mount CCTV IR Corrected 

 

I have one on order.

 

I'll be interested in the "IR corrected" performance.  I'll compare it against the 25mm & 50mm prime lenses If I ever get a clear night.....


Edited by cmooney91, 03 April 2018 - 12:10 PM.

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#31 davidparks

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Posted 03 April 2018 - 10:00 PM

I picked up a few lens’ to try:  50mm f/1.4 C-mount,  200mm f/4 M42 mount, and 500mm f/8 (with 2x teleconverter to take it to 1000mm).   I certainly had some doubts, however, they each mount easily on the ZWO ASI cameras (224/294) and come to focus on a tree 200 yards distant during daylight without vignetting.  Manual focus gave a sharp image at about the “mid” range of focus when mounted using a 21mm M42 spacer (which came with the ASI294).   Hopefully they will reach infinity focus at night, and I’ll post some results.  I think this it’s an exciting idea, and certainly fun to test out... imagine if these types of simple and relatively inexpensive lightweight lens’ find their own niche in EAA waytogo.gif

 

Mounts:

First I looked at the $70 Orion Min-EQ mount, and then adding the $60 motor drive, and this may be one of the least expensive ways to get sidereal tracking...  I then started looking at the Sky-Tracker, and Star-Adventurer mounts, and I think either of these would work great with a lightweight setup such as these being discussed, although this would cost twice as much.... of course then i had to ask myself the question “what might the smallest, lightweight, GoTo tracking mount be?”  Although GoTo might be overkill with a wide angle lens, it also might be quite necessary with the longer 200-1000mm lens’ i mentioned above...

 

Although the simplicity of a motorized Min-EQ mount, or even a DIY Barn Door Tracker has a certain appeal, I decided not to kid myself, and just admit I wanted all the bells and whistles, so I went with the new SkyWatcher AZ GTi.  It seems the most cost effective/smallest/lightweight mount with all the features of GoTo, WiFi, SkySafari, along with Freedom Find dual encoders, which allows you to release the clutches and move the scope freely in both axis without losing alignment.  My EAA typically utilizes less than 30second exposures with live stacking, so Alt/Az will be perfectly acceptable, and possibly preferable.  Hmmm, maybe it will also work on a wedge...  (down the rabbit hole)

 

In any case, I’ll post camera/lens results as soon as the weather allows, while still awaiting delivery on the mount.


Edited by davidparks, 03 April 2018 - 10:08 PM.

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#32 cmooney91

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Posted 04 April 2018 - 09:25 AM

Just a heads up in case anyone was also tempted by the large Fujinon/Cannon TV zoom lenses.

 

I received my motorized  5.5mm-88mm F1.4 zoom lens and it had terrible soft focus.

 

It turns out it has awful spherical aberration. Here's an artificial star/Bokeh test showing intra- and extra-focus.

 

ifUmcwE.jpg

RuSngl4.jpg

QAYHCu6.jpg

 

 

After researching more, and talking with the seller, it seem's I made an uninformed choice. Most of these older used broadcast lenses where only designed to be passable for standard definition, and they are optically corrected to be used with 3CCD cameras that use splitting prisms in front of 3 color sensors.

 

 

Fortunately the seller was kind enough to accept a return.

 

 

I might try again, but I need to do more research. 

 

Another thing to keep in mind about zoom lenses is the light loss due to the large number of elements, I mean look at them all, dang!

canonzoomlens.gif

 

In my brief troubleshooting tests, I compared the view through the zoom at 25mm F1.4 to the prime lens, and the zoom lens was very noticeably darker, with the same exposure and gain.

 

Oh well, learn by experience.


Edited by cmooney91, 05 April 2018 - 07:19 AM.

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#33 Adun

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Posted 04 April 2018 - 11:07 AM

I decided not to kid myself, and just admit I wanted all the bells and whistles, so I went with the new SkyWatcher AZ GTi.  It seems the most cost effective/smallest/lightweight mount with all the features of GoTo, WiFi, SkySafari, along with Freedom Find dual encoders...

 

I'm eyeing that one out to be my travel (and maybe G&G) mount. I'm awaiting for it to be released in the US (where I buy such stuff from) during NEAF.


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#34 Adun

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Posted 04 April 2018 - 11:09 AM

In my brief troubleshooting tests, I compared the view through the zoom at 25mm F1.4 to the prime lens, and the view was very noticeably darker, with the same exposure and gain.

 

Oh well, learn by experience.

 

Mine is still somewhere between China and South America... skies are completely overcast anyway, and it's been raining nonstop for days.


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#35 davidparks

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Posted 04 April 2018 - 04:36 PM

I read the SkyWatcher Az GTi would be released at NEAF, which is great, but I did not want to wait and the cost wasn’t prohibitive, so I ordered from First Light Optics, across the Pond, on Monday April 2nd, Delivery is set for Friday April 6waytogo.gif .  I’ve had shipping from the next state over take longer than that! 4.gif , so i’m quite happy with First Light Optics.

 

I’ll probably start a new thread over in the ‘Equipment’ forum about my experience with this mount, once it arrives.  I’m sure others will enjoy using this mount for many different types of setups, particularly refractors, but my interest initially is using it for the lightweight camera/lens EAA setups we are discussing here.


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#36 cmooney91

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Posted 06 April 2018 - 07:16 AM

Had a good clear night yesterday.

 

I used the opportunity to test my pico projector coupled with wide field  C-Mount EAA as a guide for 7x35 binoculars, as a dry run of future eaa assisted urban binocular outreach for groups. 

3rAs3U0.jpg

The results where good. The system worked, but could use some improvements.

  • A way to project a full screen Sharpcap image with no glaring UI.

  • Either a wider FOV 12mm lens, or a camera mounted green laser to help people get into the area displayed (25mm lens is ~12°fov, 7x35 Binos are 9.3°fov)

I am still learning how to run the camera and sharpcap, but last night was the first session where I could focus more on observing than learning the software. It was a blast!

 

Here is M81 M82, left above center. 114x4"(busy fooling around taking the above HDR picture of the setup) , 50% gain, no filter. Again no tracking mount.

56X1ZrW.jpg

 

 

Here is my favorite from the night.

Gemini, right twin, right leg area. M35 OC, Monkey head Nebula, and Jellyfish nebula(faint), all crammed onto the tiny 1/3" IMX224 sensor with no tracking mount.

46x4", 50% gain, UVIR filter

0ZOBs4M.jpg

 

I tested no filter vs. UVIR vs UHC on this region. I think UVIR maybe was slightly better, with sharper stars, and more contrast. UHC needed 100%gain and 8 Second exposures resulting in minor star trailing, so it doesn't really jive with using a fast C-mount Lens + stationary tripod.

 

Can't wait to do more!


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#37 nic35

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Posted 06 April 2018 - 10:07 AM

CM - you want:

 

A way to project a full screen Sharpcap image with no glaring UI.

 

On the SC top control line, go to options..full screen

 

You'll need to drag the borders for the control panels to minimize them, but you can get rid of most of the interface.

 

If you are using two monitors then you can drag the controls to the second monitor.

 

I'm not sure if the pico can function as a second monitor, but you may be able to keep the image on that, and "move" the control panels to your computer screen

 

Interesting setup.  How do you like the pico - and which version is that ? 

 

john



#38 Adun

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Posted 06 April 2018 - 01:49 PM

Here is M81 M82, left above center. 114x4"(busy fooling around taking the above HDR picture of the setup) , 50% gain, no filter. Again no tracking mount.

 

 

Here is my favorite from the night.

Gemini, right twin, right leg area. M35 OC, Monkey head Nebula, and Jellyfish nebula(faint), all crammed onto the tiny 1/3" IMX224 sensor with no tracking mount.

46x4", 50% gain, UVIR filter

 

 

I tested no filter vs. UVIR vs UHC on this region. I think UVIR maybe was slightly better, with sharper stars, and more contrast. UHC needed 100%gain and 8 Second exposures resulting in minor star trailing, so it doesn't really jive with using a fast C-mount Lens + stationary tripod.

 

I like those results. They are with the 25mm F1.4, right? Urban skies?

 

The first one is 114 frames x 4sec (7 minute stacking) and the second one is 46 frames x 4s (3 minute stacking), correct?

 

It seems focus is better in the top right than in the bottom left. Perhaps an alignment issue?

 

Now I'm more eager to get my hands in that lens!


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#39 davidparks

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Posted 06 April 2018 - 11:21 PM

Now awaiting clear skies...

 

SkyWatcher AZ GTi Mount. (EQ Base Optional)

ZWO ASI294 & 224

M42 mount 500mm f/8 (1000mm w/2x converter)

M42 mount 200mm f/4

C-mount 50mm f/1.4

Various other size C-mount lens, but you get the idea.

 

 
 

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#40 cmooney91

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Posted 09 April 2018 - 07:03 AM

John, 

Thanks for the tip.

 

The pico projector is the AXAA Pico HD. It can function as an extended or mirrored display 

 

The Good:

  • True 720P HD
  • Only $150 
  • Internal battery lasts ~ 1.5hr (could be longer in eco-mode)
  • Very small form factor

The Bad:

  • Mini HDMI connector (i needed to buy two types of adapters to connect to the Micro HDMI on my tablet)
  • No control buttons, Have to use the remote
  • Remote is hard to use in the dark(Sea of identical feeling membrane switches)
  • IR remote receiver is on the back of the projector, so it can be tricky to hit if its high up  and projecting on the ground.
  • Power mode and fit/zoom settings are reset on shut down.
  • Focus has a lot of backlash, but can get sharp enough to see the pixels
  • No battery indicator, it just goes on the fritz before shutting down (I was returning mine before they mentioned that. Now It works fine when charged)

All in all I think it will be good for outreach, I just need to iron out the quarks before demoing it.

 

 

Adun,

Yes that was the 25mm F1.4. I love how well it matches the FOV of 7x35 binoculars.

The light pollution map says it was 20.08mag/sqrarc-sec bortle 5 skies

 

Correct on the exposure times. M81 and M82 were visible in single 4s 3000Gain exposures, but got cleaner with stacking. the reason that was such a long stack was I was setting up my DSLR on a tripod and taking long exposure pictures of the set up to show here.

 

In the second picture M35 was easily visible in the 1/2s full gain exposures I use for framing. Monkeys head was visible after 2-4 stacks (4s 3000Gain) and stretching and white balance. The jellyfish needed the 3 minutes and careful stretching .

 

Yeah, there's a lot of distortions in the outer edge, It's the price of admission for a cheap F1.4 lens. The aberations are significantly reduced as the lens is stopped down beyond F4, but then you need longer exposures. I don't mind the aberrations, and I really like the short exposures, so I can live with it.

 

Fujinon CF25B sell used on eBay for around $70-100. It's a higher quality lens designed for 2/3 sensors, so I imagine it would be very sharp on our 1/3 sensors. But for the same price, you could have multiple cheaper lenses in different focal lengths.

 

 

David, 

 

I'm excited to see the results with that mount. I'm trying to build something similar but 2-3X capacity. I think that mount is going to EXPLODE on to the market after NEAF.

 

I can't wait to get my 50mm F1.4. I really want to know if I can still get away with using it with a stationary tripod.

 

The two longer slower lenses would need too much exposure time for me (and my lack of mount) but should be a great lightweight and small combo  with the  AZ GTi.


Edited by cmooney91, 10 April 2018 - 06:24 AM.

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#41 cmooney91

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Posted 11 April 2018 - 10:13 AM

Made a new camera-dovetail clamp that incorporates two picatinny rails so I could attach my red dot and GLP. 

qWr8Xz0.jpg

Now it looks like some kind of tacti-cool uzi, I'll probably get some strange looks on the streets.

 

 

I got to take it out last night after some passing clouds.  I set the legs of the tripod really wide and short then I sat in/under the legs in a low folding beach chair with my tablet in my lap and my 7x35 binoculars at my side.  That was a fun set up, I could aim down the RDF and access half the sky from my seat. Felt like a bomber gunner. 

 

I inadvertently saved everything as fits so I had to re-stretch and WB in gimp, so links only.

 

I re-shot M81 and M82 with a shorter total exposure time. 3500Gain, 10x4s, 40s total.

https://imgur.com/0Wim24M

 It seems much sharper. I think it's due to the significant barrel distortion in these lenses; the longer stacks start to deteriorate as the frames move across the stationary distortion field.

 

 

I aslo got M101(lower left), M51(upper right), Mizar, and Alkaid in the same frame.  3500 Gain, 7x4s, 28s total   

https://imgur.com/QKyAK4I

 

Then I tried the whale galaxy (right 1/3rd, centered) for the April EAA challenge. Bonus hockey stick(barely).

4200 Gain,  29x 4s, 116s total

https://imgur.com/a5OCr23

 

This "EAA Bino-gunner" setup is a blast. I can quickly manually point the "scope" to capture a 11°x 8.2° field on the tablet in my lap, then grab the 7x35s and recline in place, using the EAA as a guide for the 9.3° binoculars. I didn't  detect the whale, but it worked well for M81.   

 

Can't wait to try more lenses!

 

-Corey


Edited by cmooney91, 12 April 2018 - 08:11 AM.

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#42 cmooney91

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Posted 12 April 2018 - 07:42 AM

I received the 8-50mm F1.4 IR corrected lens. I made a light shroud for it and mounted it to the camera. It reached focus at all zoom levels but it is not parfocal, so it needs to be refocused when zoomed.

la5B2Us.jpg

 

At the widest 8mm zoom it could fit the whole big dipper, but I chose to compose the star hop to M81.

3500Gain 18x4s=72s

yQkfbXq.jpg

 

Most importantly, at max 50mm zoom I was able to take 4s exposures with no star trailing, phew!

With the bigger image scale I can start to make out the spiral structure of M81.

 

MaxGain, 55x4s=220s.

wtZ4bFu.jpg

 

 

After that I found the Leo Trio for the first time.

MaxGain, 36x4s=144s.

fFWZEzg.jpg

 

 

It seems there is some truth to the IR corrected claims, the stars look a lot sharper throughout the zoom range, but its hard to know for sure, it could just be a quality difference. At max zoom it seems to loose a little brightness requiring max gain for 4s exposures. Also the focus adjustment is a bit more coarse than the 25mm F1.4, but it's still manageable.

 

I will be interested to compare sharpness and brightness when my 50mm F1.4 prime comes in.

 

Also I ordered a used higher quality rainbow 25mm F1.4  lens meant for 1" sensors to compare against the low cost 25mm 1/3" lens.


Edited by cmooney91, 12 April 2018 - 08:15 AM.

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#43 fromEarth

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Posted 15 April 2018 - 11:25 PM

This is very interesting experiment! Do you recommend zoom lenses or fixed models? (25mm, 50mm, or longer?) I am going to use RT224 and my camera tripod on EQ platform, so star trailing can be handled. I am more interested in these lenses' optical quality. I do not expect too much, but am just curious.

 

BTW, I found some CCTV lenses provide higher mega pixels (5MP, 8MP etc). What does this "pixel" mean here?

 

-------------

 

8-50mm Zoom ?

 

https://www.ebay.com...872.m2749.l2649

 

25mm ?

 

https://www.ebay.com...MgAAOSw1blZoi3C

 

50mm?

 

https://www.ebay.com...nIAAOSwE~lapjAC


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#44 cmooney91

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Posted 16 April 2018 - 07:33 AM

Each have their own trade offs. 

 

The MP rating denotes how precise the lens is designed to be, the higher the better. These lenses are cost optimized; there is no need for the manufactures to make the optics fine enough to resolve a point any smaller than a pixel in an X-MP camera(RT224 is 1.2MP). I got burned by this when I bought a old standard definition TV Zoom lens (see above).

 

In general, fixed focal lenses should have sharper and brighter images because they have fewer lens elements.

 

In this case it gets a little complicated because the 8-50 lens is 3MP rated & IR corrected where the others are not.

 

I ordered all three of the lenses you linked but I am still waiting for my fixed 50mm to arrive.

 

There are some pictures from the 25mm F1.4 earlier in the thread, you can see it has a noticeable amount of distortion and edge aberrations, but I think it is still serviceable for EAA with a 1.2MP sensor.

 

I only had the chance to use the 8mm-50mm IR zoom once so far, but it seems to be a lot sharper to the edge than the Fujian 25mm. I don't know how much of this is due to the IR correction(reduced star bloat), or the 3 MP design.  The trade off is that it is noticeably slightly dimmer than the fixed focal length lens especially at max 50mm zoom. 

 

At the beginning of this thread I was recommending getting fixed focal length lenses, but after testing and comparing the 8-50mm IR corrected zoom lens I think I would recommend the Zoom (that 8-50mm IR zoom specifically). I have seen it on aliexpress for $60 also.


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#45 nic35

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Posted 19 April 2018 - 07:45 PM

So, here's my dumb question:  if I get a C mount lens, then I can use it with both my c mount camera (IMX224) and my RI version 1.2, as long as I have a 5 mm spacer for the RI camera, correct?

 

John



#46 mclewis1

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Posted 19 April 2018 - 08:18 PM

Yup ... and you may not even need the spacer. You may just find that the lens comes to focus at a different point with the RI1.2. But the use of the spacer will mean that both setups will be virtually the same in terms of focus point and fov with the lens.



#47 nic35

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Posted 19 April 2018 - 08:27 PM

thanks, mark

 

J



#48 Adun

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Posted 28 April 2018 - 11:19 AM

the 25mm F1.4 lens arrived from China this week.

 

I like its overal build:

 

25mm F1.4 lens, $18 from China

 

The iris and focus work well. I mounted it on my IMX 224 camera and did a daylight test:

 

25mm F1.4 lens mounted on RT224 EAA camera

 

I was able to focus without trouble, and took advantage of the opportunity to do a little color calibration of my sharpcap settings.

 

To get it mounted, I don't have a 3D printer (nor feel like spending on a 3D hub right now), but I did watch enough McGyver when I was a kid:

 

Ready for testing
 
That should be enough for first light. Now I just need to wait for the clouds to cooperate.

Edited by Adun, 28 April 2018 - 11:21 AM.

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#49 nic35

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Posted 28 April 2018 - 03:26 PM

Mine arrived today also.  Amazing how quickly it arrived.  daylight test with RI 1v2 looks good

 

 

I must have missed that McGyver back in the day. But I did watch enough of The New Red Green Show to know that with duct tape, anything is possible !  

 

Update:  Not able to reach infinity focus on the RI v1.2.  Looks like I need a 5mm spacer.

 

Further update:  mine is actually the 8-50mm zoom.  Short of infinity, it focuses well.

 

john


Edited by nic35, 29 April 2018 - 03:13 PM.

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#50 Adun

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Posted 29 April 2018 - 12:11 PM

I did watch enough of The New Red Green Show to know that with duct tape, anything is possible !

 
If it's good enough for NASA, it's good enough for me!
 
Last night was very cloudy, with humid air, and the moon was full (also making the clouds very bright). From my streetlight-sieged driveway under Bortle 8 skies it didn't look promising.

But that didn't stop me from trying the new lens.

I had to use very low gains. At 8s exposure I had to use the lowest gain, otherwise I just got a white washed out overexposed view. I considered closing the Iris a bit, but I think that could cost aperture and thus not be a good idea (am I wrong?).

So I captured a nice cloud-trail, stacking 29 frames of 8 seconds each (with gain at the RT224's minimum). It features a prominent cloud, but also a tiny M13.

I stretched it to better assess the optics, and to run a plate solving.

Here's the result (the orange thing is the cloud-trail), and here is the platesolving.

 

The view was a little over 6.3° according to astronometry. No problems reaching focus.

 

Some conclusions:

 

  • More of the AFoV seemed useful than I expected. The edge aberrations were there, but seemed less prevalent than I imagined.
  • It's nice how the 6° TFOV kind of matches a binocular view. 
  • The huge TFOV meant field rotation from the alt az mount crept very very very slowly. It should also mean it can take longer exposures (16s, 32s, ¿64s?) but I'll have to sort out the exposure/gain/glare thing.
  • I think I should make a light shield for this lens, the objective is just too close to the edge for use near streetlights.
  • More experiments are required with longer exposures, and with short exposure non tracking
  • I need to get myself a country house somewhere high in the mountains and away from the city

Edited by Adun, 29 April 2018 - 12:22 PM.

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