Home · Register · Search · View Winners · Software · Hosting · Software · Join Upload & Sell

Moderated by: Fred Miranda
Username   Password

FM Forum Rules
Landscape Posting Guidelines
  

FM Forums | Landscape Photographer | Join Upload & Sell

1       2       3              11      
12
       13              17       18       end
  

Archive 2013 · Nightscapes using AstroTrac Tracking Mount
  
 
dgdg
Offline
• • • •
Upload & Sell: Off
p.12 #1 · Nightscapes using AstroTrac Tracking Mount


I do have a question about the wedge after fiddling with it and reading the instructions.

1. During latitude coarse adjustment, does the Latitude coarse set screw need to be screwed into one of the mounting plate holes, or anywhere onto the plate? The holes seem fairly far apart.
2. What is the purpose of the latitude locking lever in addition to the screwed in coarse set screw?
3. What is the procedure for fine tuning the latitude polar alignment with the astrotrac and camera already attached? (polar alignment may be off slightly after finding target with the camera). I don't want to break something by forcing it.
-- do I unlock the locking lever, then turn the latitude fine adjust knob against the camera/lens weight, then lock the lever again?



Apr 10, 2013 at 02:51 AM
JameelH
Online
• • •
Upload & Sell: On
p.12 #2 · Nightscapes using AstroTrac Tracking Mount


dgdg wrote:
I do have a question about the wedge after fiddling with it and reading the instructions.

1. During latitude coarse adjustment, does the Latitude coarse set screw need to be screwed into one of the mounting plate holes, or anywhere onto the plate? The holes seem fairly far apart.
2. What is the purpose of the latitude locking lever in addition to the screwed in coarse set screw?
3. What is the procedure for fine tuning the latitude polar alignment with the astrotrac and camera already attached? (polar alignment may be off slightly after finding target with the camera). I don't want to
...Show more

1. Anywhere on the plate. The fine adjustment goes +/- 5 degrees or so.
2. The locking lever locks down the latitude adjustment i.e. the fine adjustment knob cannot be used after lock down. The idea is to lock it once polar alignment is achieved and it cannot accidently be changed.
3. See above. Yes the locking level needs to be loosened before fine adjust and then locked back again.

Hope this helps.



Apr 10, 2013 at 05:39 AM
dgdg
Offline
• • • •
Upload & Sell: Off
p.12 #3 · Nightscapes using AstroTrac Tracking Mount


thanks jamee
I emailed Richard as well. He noted that the coarse latitude set screw should go fully in one of the mounting plate holes. wish the directions were more clear.

thanks for your tips. I appreciate your experience - I don't want to force it and break something.



Apr 10, 2013 at 06:32 PM
msoomro
Offline
• • •
Upload & Sell: On
p.12 #4 · Nightscapes using AstroTrac Tracking Mount


Very interesting topic. Tagging to follow up on discussion


Apr 17, 2013 at 07:56 PM
Todd
Offline
• • •
Upload & Sell: Off
p.12 #5 · Nightscapes using AstroTrac Tracking Mount


I went out last night to a dark location and the skies were great and very transparent. I checked the clear sky clock before going out, it is a cool tool if any of you use it. If any of you don't know what it is, look here: http://cleardarksky.com/csk/index.html#chart_list
I used my Nikon D800E last night and tested a used lens I just bought, The Nikon 500mm F/8 Reflex lens. It is slow, but I was pleasantly surprised on how it performed. I was more concerned about how it would guide on the AstroTrac. Well to my amazement, it tracked perfectly and my longest exposure was 8 minutes.

I made a few modifications to the polar scope holder on the AstroTrac. I found that one of the magnets was not fully counter sunk, it was raised slightly and this made the scope lean a bit. I managed to press the magnet in using pliers and then I noticed the scope had some side to side slop in the holder. I fixed this by adding a thin strip of gaffer tape (great stuff) and put a piece in the inner part of the holder and it does not go all the way around, but half way (180) and this gave the polar scope a no-slack fit.

The astroTrac now tracks better than ever. I am very pleased. Here are three photos from last night:

1. M8 & M20
Nikon D800E and 500mm f/8 mirror lens
ISO 1250 for 6 min







2. M8 & M20
Nikon D800E with 70-200mm F/2.8G VRII @ 200mm
F/4, ISO 400, 7 min







3. Comet Pan-STARRS and meteor
Nikon D800E with 70-200mm F/2.8G VRII @ 200mm
F/4, 4 min ISO 400







Questions and or comment welcome

Todd



Apr 21, 2013 at 03:17 AM
JimFox
Offline
• • • • • • •
Moderator
Upload & Sell: On
p.12 #6 · Nightscapes using AstroTrac Tracking Mount


Hey Todd,

What cool shots you got here, I would say you nailed these!

Jim



Apr 21, 2013 at 05:08 AM
msoomro
Offline
• • •
Upload & Sell: On
p.12 #7 · Nightscapes using AstroTrac Tracking Mount


These are beautiful shots.


Apr 21, 2013 at 05:32 AM
JameelH
Online
• • •
Upload & Sell: On
p.12 #8 · Nightscapes using AstroTrac Tracking Mount


For those using the astrotrac (and similar tracking devices), can you share your technique for composing the shots?

thanks



Apr 21, 2013 at 07:24 AM
Todd
Offline
• • •
Upload & Sell: Off
p.12 #9 · Nightscapes using AstroTrac Tracking Mount


JameelH wrote:
For those using the astrotrac (and similar tracking devices), can you share your technique for composing the shots?

thanks


Hey JameelH,

The technique for the AstroTrac is fairly simple. I start by getting mine ready to track by mounting the camera and lens choice to the ball head on the AstroTrac so the weight of the camera will be accounted for when polar aligning the unit. Once the camera is aimed and focused on the object of choice, I align the astrotrac using the polar scope. I also hang a 10 pound weight from my tripod to help stabilize it more and then I set my MC-36 remote timer to the desired exposure (usually 3-8 minutes) and use mirror lockup and time delay to get rid of shutter vibration. That's pretty much it... fairly simple. It may be frustrating on the first attempt, but it gets easy fast. I can set this up and start shooting within 10 minutes...hope this helps.

Todd



Apr 21, 2013 at 03:15 PM
astro-ep
Offline
• • •
Upload & Sell: On
p.12 #10 · Nightscapes using AstroTrac Tracking Mount


Nice shots, Todd. I too use the Clear Sly clock for my area. It tracks fairly well, when you're location is directly in a frontal path (of a storm or something). Here in El Paso, we seem to have a lot of tangential flow, where El Paso is on or near the centerline of opposing flows. This seems to make the CSC a little less predictable.

Another tool I use is the GOES water vapor maps. The blacker the drier the air.
East: www.goes.noaa.gov/GSSLOOPS/ecwv.html
West:www.goes.noaa.gov/GSSLOOPS/wcwv.html

One final note: On your last image of the Comet. There is a significant gradient across the frame. This is pretty common. If you don't already have one you should look at buying a gradient removal tool line GradientXterminator (GXT), Carboni Tools, or similar. I use GXT with very good success.

Thanks for sharing your fantastic shots...

Eric

EDIT Longhorn Baseball was Smoking yesterday (Saturday).



Apr 21, 2013 at 03:52 PM
 

Search in Used Dept. 



harshaj1
Offline
• • • • • •
Upload & Sell: On
p.12 #11 · Nightscapes using AstroTrac Tracking Mount


Todd wrote:
I went out last night to a dark location and the skies were great and very transparent. I checked the clear sky clock before going out, it is a cool tool if any of you use it. If any of you don't know what it is, look here: http://cleardarksky.com/csk/index.html#chart_list
I used my Nikon D800E last night and tested a used lens I just bought, The Nikon 500mm F/8 Reflex lens. It is slow, but I was pleasantly surprised on how it performed. I was more concerned about how it would guide on the AstroTrac. Well to my amazement, it tracked
...Show more

Excellent shots Todd. I have a similar rig to your minus the reflex lens. I had good tracking with my 200-400 lens up to 7 minutes. Waiting for clear nights.
Harsha



Apr 22, 2013 at 01:24 AM
JameelH
Online
• • •
Upload & Sell: On
p.12 #12 · Nightscapes using AstroTrac Tracking Mount


Todd wrote:
Hey JameelH,

The technique for the AstroTrac is fairly simple. I start by getting mine ready to track by mounting the camera and lens choice to the ball head on the AstroTrac so the weight of the camera will be accounted for when polar aligning the unit. Once the camera is aimed and focused on the object of choice, I align the astrotrac using the polar scope. I also hang a 10 pound weight from my tripod to help stabilize it more and then I set my MC-36 remote timer to the desired exposure (usually 3-8 minutes) and use mirror lockup
...Show more

Todd, thanks for the response. My question was related to composing the subject - neither viewfinder nor liveview is useful. How exactly does one point to the object of interest.

thanks



Apr 22, 2013 at 04:54 AM
dgdg
Offline
• • • •
Upload & Sell: Off
p.12 #13 · Nightscapes using AstroTrac Tracking Mount


Jamee,
If I am imaging with a 400 mm lens, finding an object is not always easy and repeated attempts result in messing up polar alignment.
I use a Rigel quickfinder attached to the hot shoe of my camera. Required purchasing a separate inexpensive HDE 1/4"- 20 Tripod Screw to Hot Shoe Adapter . The nut seemed too tall while trying to set it up for hot shoe mounting. It was hitting the battery, so I went to our local hardware store for a smaller nut and that worked fine. Anyway, point your camera to a bright star and make sure the star is in the center of your quickfinder and live view by adjusting the position of your finder. You'd set up manual focus as well at this time. With the finder aligned, screw it down to lock it. This will get you close enough for finding your objects. Then as you move your camera across the night sky, you can use the quickfinder to locate your small object. Clearly, you still need to star hop - know where to find it using a chart and visible stars. I found the rose nebula quickly with this approach with a 640mm fov. The processing is the kicker!
http://www.highpointscientific.com/product/RGL-R-CRS/Rigel-Quickfinder--Rigel-Systems-Quick-Finder.html?meta=GAW&metacpg=RGL-R-CRS&gclid=COaz_pfD3rYCFYU5Qgod8XoATA
http://www.amazon.com/gp/product/B005005EEM/ref=oh_details_o02_s00_i00?ie=UTF8&psc=1
I think next time I'm out, I will play with using the geared head on top of the AT instead of a ball head. Sometimes you get close.....then lose it...then kick your tripod.....



Apr 22, 2013 at 02:53 PM
Fred Miranda
Offline
Admin
Upload & Sell: On
p.12 #14 · Nightscapes using AstroTrac Tracking Mount


JameelH wrote:
Todd, thanks for the response. My question was related to composing the subject - neither viewfinder nor liveview is useful. How exactly does one point to the object of interest.

thanks


I believe that for our astrotrac + DSLR gear, there is a lot of trial and error when composing. I usually roughly find the target using the camera viewfinder while taking in consideration possible 'flexure' from using a heavy lens.
-Fred



Apr 22, 2013 at 04:13 PM
Fred Miranda
Offline
Admin
Upload & Sell: On
p.12 #15 · Nightscapes using AstroTrac Tracking Mount


Todd wrote:
I went out last night to a dark location and the skies were great and very transparent. I checked the clear sky clock before going out, it is a cool tool if any of you use it. If any of you don't know what it is, look here: http://cleardarksky.com/csk/index.html#chart_list
I used my Nikon D800E last night and tested a used lens I just bought, The Nikon 500mm F/8 Reflex lens. It is slow, but I was pleasantly surprised on how it performed. I was more concerned about how it would guide on the AstroTrac. Well to my amazement, it tracked
...Show more

Looks great Todd!
I particularly like the way you composed the second one. I have gotten cloudy skies here in San Clemente for a while...
Thanks for sharing your shots and technical info.
Best,
Fred



Apr 22, 2013 at 04:15 PM
kodakeos
Offline
• • •
Upload & Sell: On
p.12 #16 · Nightscapes using AstroTrac Tracking Mount


Just jumped over here from the General gear thread i posted about the Polarie, but it looks like the one Fred listed, ioptron_3300w_skytracker_camera_mount sounds like the same price, but WITH the aligner and more weight capacity.

Has anyone used one without the pano base? I expect that once its aligned, everything can be done from the ball head? And the alignment would just need to be done twisting the legs of the 'pod, no?



Apr 23, 2013 at 04:01 PM
orakazu
Offline

Upload & Sell: On
p.12 #17 · Nightscapes using AstroTrac Tracking Mount


I already have a BH-55, sturdy tripod, EF 500mm II, and am in the process of getting a 6D with IR-filter removed. So if I add an Astrotrac, wedge, polar scope, and eventually a guiding scope and CCD with PHD on a laptop, my setup should be similar.

I was hoping someone could tell me about how astro filters could be used in the Canon EF 500mm f/4L IS II lens. I haven't used any filters with mine yet, but it can supposedly take 52mm threaded filters or slim filters (just the filter part) in a gel holder.

I've noticed that all the typical astro filters are either 1.25" or 2" (probably for telescopes). 2" is pretty close to 52mm, but is it exactly 2" and won't work in the 500 II?

I can see myself eventually getting dedicated telescopes, but for now would like to repurpose the 500mm. What's the recommended solution for this situation? Take out just the filter film from a 2" one and put it in the gel holder?

Thanks!
Kaz



May 05, 2013 at 09:42 PM
Andrew Welsh
Offline
• • • •
Upload & Sell: On
p.12 #18 · Nightscapes using AstroTrac Tracking Mount


orakazu wrote:
I was hoping someone could tell me about how astro filters could be used in the Canon EF 500mm f/4L IS II lens. I haven't used any filters with mine yet, but it can supposedly take 52mm threaded filters or slim filters (just the filter part) in a gel holder.


Kaz, this probably doesn't help you, but might help others. I have a 40D that is modded, and I use the Hutech front filters. They rest inside the camera body. It's awesome because one light pollution or UV/IR filter works with every EF lens or telescope I own. I think they only fit on crop cameras (Rebel, 40/50/60D etc) though.

Also, I astro-tested the 500/4L IS and it is indeed one of the better astro-worthy lenses made by Canon. Stopping down to f/4.5 made it near perfect in the corners on full frame, if the diffraction pattern of the aperture blades doesn't bug you. Here are the results at f/4.0, which might be 'good enough' for most. (good enough for me!)







May 06, 2013 at 01:48 PM
dgdg
Offline
• • • •
Upload & Sell: Off
p.12 #19 · Nightscapes using AstroTrac Tracking Mount


The 400 DO works very well wide open too. I have a rose nebula shot I took last month that I am still learning how to process. The image from DSS is good, but my learning curve for editing will take some time and I need to be patient. I'm going through the making every pixel perfect videos and they are very helpful so far.


May 06, 2013 at 01:53 PM
astro-ep
Offline
• • •
Upload & Sell: On
p.12 #20 · Nightscapes using AstroTrac Tracking Mount


Coma, on the edges of astro images, is fairly common. Many scope manufacturers sell dedicated field flatteners designed for removing/reducing the coma. This problem is usually compounded with larger sensors. Andrew's 500, would probably be near perfect with a crop camera. This could be an ideal set-up, since you can use a full frame for nebula season (where you need a wider FOV) and a crop sensor (during galaxy season, when you need a little more reach).

Star images are really taxing on equipment, as every bit of field curvature or misalignment is evident. I suppose I'm a purist and want round stars to the corner of the frame, and have gone through several set-up's to achieve this. I also use a full frame sensor, but it's a dedicated astro CCD. A full frame sensor properly set-up and matched to a Takahashi FSQ-106ED will produce pinpoint stars all across the frame. Here's a star field that I did a few years ago.







The FSQ-106 is similar to the Canon 500, with a focal length of 530mm. At f5, it's a fairly fast scope. It also is a phenomenal scope/lens for terrestrial shots. Coupled to a DSLR it works well for bird and landscape shots (however not autofocus). Although similar in weight, it will end-up weighing a little more with mounting rings and mounting plate (it has no tripod mount).

There are a couple advantages of using a telescope with a dedicated sensor over a lens and DSLR. First, it's far easier to incorporate filters in a dedicated telescope system (and for the best results you'll want to use filters). They are readily available in the proper size and have housings (called filter wheels) that typically hold 5, 7 or 9 filters. Next is shooting with a dedicated CCD. These are available as color sensors (with installed Bayer matrix), but most prefer the use of a monochrome camera and filters. These dedicated CCD's have cooling to reduce noise, and large pixels to aid in efficiency. The big advantage, over a color sensor, is that each filtered image is full resolution. A typical color CMOS sensor uses a Bayer Matrix of RGGB. So in a 20MP sensor, ~5,000 pixels are red, ~5,000 are blue and ~10,000 are green. With a 10K Monochrome CCD, you shoot through filters and each image is 10,000 pixels. The difference between a combined monochrome CCD and a color CMOS is quite amazing. Finally, the cooling of dedicated CCD's helps to reduce the noise inherent to these types of sensors. CCD's tend to have less noise (vs CMOS), at the expense of requiring a lot more power. When cooled, the noise is substantially reduced. The noise level is cut in half for every ~5 degrees of temperature drop. I typically shoot with my sensor at -30C, which reduces the noise to a very low level.

The cost the FSQ-106ED itself, is less than than a EF500 lens but will produce spectacularly fine and round stars on a full-frame camera, provided the camera is mounted precisely perpendicular and on-axis. The down-side is that once you have it, you'll want the dedicated CCD, filters and filter wheel, EQ mount and other bits and pieces to get it all working together. Then you're about 2.5 to 3X the cost of the EF 500 I think I've posted it before, but here's what a typical short focal length (wide field) CCD imaging system look like.







I just thought I'd share these details, in case anyone was thinking of making the plunge into dedicated astro.

Eric

PS love this thread...



May 06, 2013 at 03:02 PM
1       2       3              11      
12
       13              17       18       end




FM Forums | Landscape Photographer | Join Upload & Sell

1       2       3              11      
12
       13              17       18       end
    
 

You are not logged in. Login or Register

Username   Password    Retrive password