Transit of Mercury - May 9, 2016

Is anyone else preparing to photograph the transit of Mercury on May 9th of this year?

This is the first transit of Mercury in 10 years. Unfortunately, during the transit of Venus that made so much news a few years ago, I had bad weather during the event. So I never picked up a solar filter for my telescope. I'm hoping that this year I'll be lucky enough to be able to see this, and photograph it through my telescope.

For people that don't know, a transit is when a planet (either Mercury or Venus) crosses the face of the Sun from our perspective on Earth. In order to view the transit, you'll have to take precautions to protect your eyesight and equipment. Special filters are required for optical equipment like telescopes or binoculars. Even pointing your telescope at the Sun without a filter can damage your gear, and *never* look through any unfiltered lens at the Sun. I have included links below for more information, and one specifically on how to safely view the transit.

The whole thing is going to last longer than 7 hours, and parts of the world, including eastern North America, will be able to view the entire transit. Anywhere on Earth that it is daytime between the start & finish of the transit will be able to see some of it; if you can see the Sun, you can see the transit. All of North America will be able to see some of it, including the moment of mid-transit (when Mercury is in the middle of crossing the Sun's face).

Geocentric Phases of the 2016 Transit of Mercury
Times are in UTC
Contact I 11:12:19
Contact II 11:15:31
Mid-Transit 14:57:26
Contact III 18:39:14
Contact IV 18:42:26

Additional Information:

This site is chock full of great information:
http://www.nakedeyepla​nets.com/mercury-transit-2016.htm

Map of the Earth showing where & when the transit will be visible. Click on your location on the map, and it will tell you the time of each event, and the Alt/Azi to see it. This is a pretty sweet tool useful for Mercury and Venus transits.
http://xjubier.free.fr …3.php?Trt=+2016​0509&Acc=2

http://eclipsewise.com​/oh/tm2016.html

How to safely watch the transit:
http://www.nakedeyepla​nets.com …nsit-2016.htm#observesafe

I'll certainly be observing the event live. I'm not sure if I'll be doing any imaging. I have both a Hydrogen alpha dedicated solar scope as well a white light filter for my refractor. But my astronomhy club will be doing outreach for the public on that day and usually doing outreach is not compatible with imaging (too much going on at the same time.)

If you don't already own a solar filter then you'll want to get that soon. At the transit of Venus in 2012 any vendor of filters ran out of stock in the month's preceeding the event and they were difficult to find.

TCampbell wrote in post #17904645
I'll certainly be observing the event live. I'm not sure if I'll be doing any imaging. I have both a Hydrogen alpha dedicated solar scope as well a white light filter for my refractor. But my astronomhy club will be doing outreach for the public on that day and usually doing outreach is not compatible with imaging (too much going on at the same time.)

If you don't already own a solar filter then you'll want to get that soon. At the transit of Venus in 2012 any vendor of filters ran out of stock in the month's preceeding the event and they were difficult to find.

That's cool. Sounds like a fun day regardless of not getting to image. Yeah, I'm researching my solar filter now. The one I had picked out 4 years ago is unsurprisingly out of stock now.

heldGaze wrote in post #17904868

That's cool. Sounds like a fun day regardless of not getting to image. Yeah, I'm researching my solar filter now. The one I had picked out 4 years ago is unsurprisingly out of stock now.

Check ThousandOaksOptical.co​m They list the size for your LXD-55 6" S/NEWT scope. 150mm/6" of clear aperture designed to fit over a 190mm/7.5" optical tube (they usually include two thickness of felt lining that you use to line the inside of the filter's cap depending on how snugly it needs to fit for your scope.

They make it in RG-Film ($69), Glass ($109), or Black Polymer ($59)

I've purchased several solar filters for them for different scopes.

Incidentally, I know their glass and black polymer filters render the sun in an orange color (they block a little more of the blue side of the spectrum than the red side, so the sun appears orange.)

Their RG film renders the sun closer to white (a bit of yellowish ivory - hue, but it's not orange.)

For CAMERA lenses (instead of telescopes) they actually do recommend that you stick to the black polymer film and don't use the RG film or the glass. The reason for this is that the RG film looks like aluminum foil and the glass filter looks like a mirror. These very highly reflective surfaces can cause ghosting when placed just in front of a camera lens. But the black polymer film literally is just black and typically won't provide enough of a reflection to cause ghosting.

If I do get to setup a camera for some imaging (I'll try to sneak that in) then I'll be doing that through a telescope -- through a telescope you can use any filter you want (the filter is too far forward in the optical path to cause ghosting.)

These days I use a Herschel solar wedge. I bought a 4" apochromatic refractor (TeleVue NP101is) and opted to switch to the wedge (mine is the Lunt brand white light solar wedge) because the image is a bit sharper. But the "catch" with the Herschel wedge is that since it mounts on the back of the scope instead of the front, it can only be used on scopes that can take the heat. So that typically means it's limited to refractors of about 4" or smaller focal lengths. You can't use a Herschel wedge on any reflector type telescope (that would be very dangerous.) Solar filters that mount to the front can be used on any telescope since they reject most of the energy before it even enters the optical tube.

Solar filters typically have an optical density of 5.0 (each 0.1 = 1/3rd of a photographic stop). That works out to only 1/100,000th of the light can pass through the filter. A solar filter has to block 99.996% of all the light to be safe (that's the minimum) and it must do this across the entire spectrum (including blocking the IR wavelengths). Most solar filters block 99.999%.

Now all we need to do is hire a reputable witch doctor to perform the necessary rituals to keep the clouds away. Any recommendations?

Thanks TCampbell, I'll probably get my filter from that site. So I'm guessing your recommendation is the RG film for best color on the telescope?

Yeah - I prefer the "whiter" filters because you can adjust color on the image later (or if you want to adjust color for visual you can slip on a colored filtered on the eyepiece). Thousand Oaks Optical claims the RG-Film has the lowest optical distortion of any of their filters (that surprised me... I thought the true "glass" would be better, but it's not.)

I noticed the Kendrick website (Kendrick also makes solar filters) says their filter prices will go up 30% on April 1 and remain there until after the transit on May 9 (then return to normal pricing). Astrozap also sells solar filters.

TCampbell wrote in post #17906307
Yeah - I prefer the "whiter" filters because you can adjust color on the image later (or if you want to adjust color for visual you can slip on a colored filtered on the eyepiece). Thousand Oaks Optical claims the RG-Film has the lowest optical distortion of any of their filters (that surprised me... I thought the true "glass" would be better, but it's not.)

I noticed the Kendrick website (Kendrick also makes solar filters) says their filter prices will go up 30% on April 1 and remain there until after the transit on May 9 (then return to normal pricing). Astrozap also sells solar filters.

Haha, cashing in on the event. Thanks for the heads up on that. $70 ain't bad for a solar filter for a 6" scope. I'll be picking this up soon so I'm ready for the event. I was also considering a H-Alpha filter, but that is a bit out of my price range right now, also Thousand Oaks H-Alpha system won't work with a SN telescope.

I hope you get a chance to do some imaging. If we get good weather I'll be sure to share my results here in the forums.

Since we're still over 2 months out, the exact time and place will change, but there is a current prediction that the ISS will transit the Sun at 12:39 near Charlotte, N.C. (bonus: at an altitude of 69 degrees). I'll be keeping an eye on this. It would be really cool to get Mercury and the ISS in the same shot.

I have a homemade solar filter using solar film (Thousand Oaks if I recall correctly). The problem with it is that it eliminates so much light that high shutter speeds are impossible. Is there a filter that eliminates dangerous IR light but still would let in enough to get a high shutter speed?

I caught a really good ISS transit last year using a ND filter only (obviously risking damaging my camera/lens). All went well, but I would rather use a solar filter if possible.

sandwedge wrote in post #17908436
Since we're still over 2 months out, the exact time and place will change, but there is a current prediction that the ISS will transit the Sun at 12:39 near Charlotte, N.C. (bonus: at an altitude of 69 degrees). I'll be keeping an eye on this. It would be really cool to get Mercury and the ISS in the same shot.

I have a homemade solar filter using solar film (Thousand Oaks if I recall correctly). The problem with it is that it eliminates so much light that high shutter speeds are impossible. Is there a filter that eliminates dangerous IR light but still would let in enough to get a high shutter speed?

I caught a really good ISS transit last year using a ND filter only (obviously risking damaging my camera/lens). All went well, but I would rather use a solar filter if possible.

That would be awesome! I had no idea and didn't even think to check Heavens-Above as we neared. I will definitely do that. I hope the NC prediction is a touch off and it's GA instead

sandwedge wrote in post #17908436
Since we're still over 2 months out, the exact time and place will change, but there is a current prediction that the ISS will transit the Sun at 12:39 near Charlotte, N.C. (bonus: at an altitude of 69 degrees). I'll be keeping an eye on this. It would be really cool to get Mercury and the ISS in the same shot.

I have a homemade solar filter using solar film (Thousand Oaks if I recall correctly). The problem with it is that it eliminates so much light that high shutter speeds are impossible. Is there a filter that eliminates dangerous IR light but still would let in enough to get a high shutter speed?

I caught a really good ISS transit last year using a ND filter only (obviously risking damaging my camera/lens). All went well, but I would rather use a solar filter if possible.

What are you planning to use to image with (telescope or camera lens?)

I've got quite a few solar images and as I review my settings... ISO 100, f/5.6 and 1/1000th sec exposure with the Thousand Oaks solar filter on the scope (I think this image I'm staring at was taken with the "glass" filter which renders the sun as orange instead of white.) It would easily be possible to get an exposure of the ISS transiting the sun at 1/2000th sec. shutter speed just by boosting the ISO or opening the aperture by a stop.

If you're using a telescope then you don't have an adjustable aperture, but you can still adjust the ISO.

I think you'll probably be ok with the stock solar filters. I probably wouldn't trust anything other than a true solar filter. There's a very informative YouTube video that discusses the safety of observing the sun (this was recorded for the Transit of Venus several years ago but would still be applicable to the Transit of Mercury.)

Here's the link: https://www.youtube.co​m/watch?v=4RGr9FcBrSM

Here's the shot through the Thousand Oaks Glass -- but it was attached to the front of my Canon EF 300mm f/2.8 IS USM lens. I've cropped in a bit on this (the Sun would not fill this much of a frame at 300mm... you'd need closer to 1000mm to mostly fill the frame on an APS-C camera and you could even go a few hundred millimeters longer.)

You can also check Calsky.com for ISS transits of the Moon or Sun (they do a lot of other stuff too.)

TCampbell wrote in post #17908602
You can also check Calsky.com for ISS transits of the Moon or Sun (they do a lot of other stuff too.)

I will definitely check out this site, thanks for the tip. Heavens-Above does a few other things too, Hubble, the Chinese Space Station, Iridium Flares, etc. I really would love to spot an Iridium Flare midday some time, though I honestly have not tried to yet. I've only used Heavens-Above to image the ISS as it passed by my parents backyard and show it to friends in the sky. This is the image I created back then, though I am thinking about reprocessing the RAWs now that my PS skills are better: The ISS Passes Under Polaris

heldGaze wrote in post #17908583
That would be awesome! I had no idea and didn't even think to check Heavens-Above as we neared. I will definitely do that. I hope the NC prediction is a touch off and it's GA instead

I'm in Atlanta also, so yes, it would be nice. I used calsky for the prediction - great resource. The centerline will definitely change between now and then. It's so far out, it may not happen anywhere near us.

TCampbell wrote in post #17908592
What are you planning to use to image with (telescope or camera lens?)

I've got quite a few solar images and as I review my settings... ISO 100, f/5.6 and 1/1000th sec exposure with the Thousand Oaks solar filter on the scope (I think this image I'm staring at was taken with the "glass" filter which renders the sun as orange instead of white.) It would easily be possible to get an exposure of the ISS transiting the sun at 1/2000th sec. shutter speed just by boosting the ISO or opening the aperture by a stop.

If you're using a telescope then you don't have an adjustable aperture, but you can still adjust the ISO.

I think you'll probably be ok with the stock solar filters. I probably wouldn't trust anything other than a true solar filter. There's a very informative YouTube video that discusses the safety of observing the sun (this was recorded for the Transit of Venus several years ago but would still be applicable to the Transit of Mercury.)

Here's the link: https://www.youtube.co​m/watch?v=4RGr9FcBrSM

Here's the shot through the Thousand Oaks Glass -- but it was attached to the front of my Canon EF 300mm f/2.8 IS USM lens. I've cropped in a bit on this (the Sun would not fill this much of a frame at 300mm... you'd need closer to 1000mm to mostly fill the frame on an APS-C camera and you could even go a few hundred millimeters longer.)

Hosted photo: posted by TCampbell in
./showthread.php?p=179​08592&i=i69775355
forum: Astronomy & Celestial

This was a partial solar eclipse back in October of 2014 when I shot this (the missing chunk of the sun is the moon... incidentally the largest sunspot of this 11 year sunspot cycle happened to be prominently featured on the face of the sun on that particular day.)

I've used the Thousand Oaks film and I don't remember it giving me that much light, but I can't remember the exact settings.

My best result was with a 7D, 100-400 and 2x converter (probably in my gallery and definitely on the first page of my Flickr link below). I've got a Sigma 150-600C now, so I'll be using it (not sure about tc yet).

I'm also considering getting a telescope. I can't really afford anything too extravagant, but I'm heading to Yellowstone in late May and staying 3-4 weeks. If there's ever a time for me to get something with goto abilities it would be now. I remember being out there in the 90's and being amazed by the stars. I'd like something that lets me get a taste of astronomy. I'd like it to have the ability to catch ISS solar and lunar transits also. Thinking about getting a celestron 6se bundle.

edit: My best effort wasn't in my gallery, so here it is:


(cropped)

IMAGE LINK: https://dougmoon.smugm​ug.com …2015-2974-XL.jpg&lb=1&s=A

sandwedge wrote in post #17908720
edit: My best effort wasn't in my gallery, so here it is:


(cropped)

IMAGE LINK: https://dougmoon.smugm​ug.com …2015-2974-XL.jpg&lb=1&s=A on Smugmug

Awesome!