Is it possible to focus on infinity at night?

[Inspeqtor]

Does anyone have a trick as to how to focus on infinity for shooting stars at night when there is no moon out? When the moon is out I will focus on the moon, but when the moon is not out, I have no way to focus on the stars.

Thank you!

[Chuck S.]

Charles, I would turn off Autofocus on the lens and manually focus to infinity - you should be able to get a good idea of the focal point from the viewfinder. I would also turn off the lens IS, then mount your camera on a tripod. And then I'd probably use Manual on the camera as well, experimenting with various shutter speeds (long ones!).

[Byron Gale]

Charles,

Interestingly, my D80 can tell that the moon is not at "infinity"... because I have to pull the focus back just a bit from the end of the range to properly focus on the moon. The auto-focus also does not go to the extreme of the focus range when pointed to the moon.

I find it amazing that the Nikon engineers could make the camera so sensitive that it could tell the difference between 239,000 miles, and infinity.

Either that, or my lens needs a setting for "Infinity - and BEYOND!!" :p

Byron

[Chuck S.]

Byron, I've had the same experience with my cameras, i.e., just pushing the lens all the way its mechanical stop can throw distant objects out of focus. That's why I suggested trying to focus using the viewfinder, although that's a bit of a challenge....

[Inspeqtor]

Chuck and Byron,

Thank you both for your comments. I should have said in my posting, than I did indeed turn off auto-focus and IS. If I had left AF on, the camera would have 'tried' to focus on space but not found anything. I also did try to manual focus, but looking thru the view finder it is hard to see the stars. I also knew not to focus until the ring stopped turning, and did turn it back a slight bit.

Sounds like I did everything right, but as you said Chuck, it is difficult. I will post a photo here in a minute. I need to resize one.

[Inspeqtor]

Here are 3 shots. The first one shows a lot of stars but is slightly out of focus. I had the lens open on this one 90 seconds.

http://www.pixentral.com/hosted/1BDvGMdlNX7JoFsUBMphKd1cD1eY_thumb.jpg (http://www.pixentral.com/show.php?picture=1BDvGMdlNX7JoFsUBMphKd1cD1eY)

This next one is badly out of focus. The lens was open 60 seconds. I was able to see this in the LCD screen right after I took the shot.

http://www.pixentral.com/hosted/13HTlKtDvi4sV0XvU73aVXWsQhoFPW0_thumb.jpg (http://www.pixentral.com/show.php?picture=13HTlKtDvi4sV0XvU73aVXWsQhoFPW0)

This last one, the focus is probably the best I was going to get. If the moon had been out, I could have done much better. On the flip side, without the moon, more stars are visible.

http://www.pixentral.com/hosted/1n4wGxa0sXhlLka58RcHAfRCXgRfj1_thumb.jpg (http://www.pixentral.com/show.php?picture=1n4wGxa0sXhlLka58RcHAfRCXgRfj1)

These shots show more stars than I am able to see with just my eyes, since I left the lens open longer.

[Chuck S.]

Charles, that's my favorite constellation you're photographing! :)

[Inspeqtor]

Chuck,

It seems to me like it has been several years since I have seen the Little Dipper!

I was thrilled when I saw it last night when I got home from work at 3:00AM!

I have seen the Big Dipper many times each year but seldom the Little Dipper.

[Danudin]

I have been struggling with a similar problem and thought of taking a "Daylight" shot of the moon Exposure 1/50th sec f5.0 ISO200 Focal length 120mm. Then follow up with a "Night Landscape" of the same shot (more or less) Exposure 1.00 sec f4.2 ISO200 Focal length 120mm.

I intend to merge the daylight moon into the night landscape, to show the details it shows. I used this pair to show what happens to nearby stars with the day shot and the moon with long exposure.
Ron
(hope this is constructive- you have helped me)

[Not4wood]

Nice shots there...

Problem with long exposures I am sure you all are seeing is the actual movement of both our planet and the stars themselves.

As far as the Dipper(s) are concerned I also see Orion's Belt and we are able to see them all thru the Winter. I don't think we have had them show there colors as of yet up here in the North East but its getting close to that time of year.

[Derry]

agree on placing the camera on manual focus and working from there,, start at full out and work back a small amount of focus (very minor move on the ring) on several photos viewing after each shot,, you will quickly find the exact setting on that specific lens for infinity focus,,

as for any longer than a few seconds you will need a mount aligned to Polaris and motorized to track and follow allowing pin point star capture,, Orion is always a good winter view,,

have included a couple of my astro items,,

Derry

[Inspeqtor]

agree on placing the camera on manual focus and working from there,, start at full out and work back a small amount of focus (very minor move on the ring) on several photos viewing after each shot,, you will quickly find the exact setting on that specific lens for infinity focus,,

as for any longer than a few seconds you will need a mount aligned to Polaris and motorized to track and follow allowing pin point star capture,, Orion is always a good winter view,,

have included a couple of my astro items,,

Derry

Derry,

I am blown away with your 2 photos! They are fantastic! That is something I would love to be able to do. What power lens were you using? I am going to show my ignorance here... what do you mean by you will need a mount aligned to Polaris and motorized to track ? I am assuming you will need a tripod with a motorized mount to follow the stars/objects you wish to follow.

How did you photograph the sun? I have no idea how to point the camera at the sun, be able to focus on it thru the view finder without being blinded.

Thank you :)

[Derry]

Charles,, been an astronomy guy for many years but now days I like to sleep at night,,:)

I presently have a Tele Vue 85 (TV85) telescope that I can either shoot in prime focus (no eyepieces with camera mounted directly to the scope) or in afocal mode (camera mounted on any TV eyepiece) which offers very high power if needed,,

I don't have the data at fingertips on the actual photos for the X factor (power) but would imagine the moon was in the 40X and the sun spots around 100X,,

I also shoot through a Questar 3.5" scope,,

I have used a Bogen 3046 tripod 3063 head for many years with good results but it does not offer any tracking for long exposures,,

to shoot the sun I have solar filters that block out about 98% of the sun light allowing you to view or photograph very bright objects as the sun or a welding rod in process,, as we all know you do not ever look at the sun and especially through a telescope or instant unrecoverable eye damage will occur,, the filters make it very safe for our eyes and any camera you want to use,,

for long exposures you need a mount that can align on Polaris and then will actually follow the star across the sky, an equatorial mount,, these are motor driven or controlled by mechanical knobs,, the motor ones do a better job and can be costly for the better ones,, may want to check out Sky and Telescope site for some reading,,

I have attached a photo of each scope with my Oly E3 mounted in the prime mode (no eyepiece),,

Derry

[mljrbg]

Awesome pictures!! That's quite a setup you have. I guess that's why my husband told me I can't photograph the moon with my 70-300 VR lens!!

Mary Lou

[Danudin]

I don't have VR on this lens but am happy with the results.
See "The Moon came up too early in my Gallery"

Not up to Derry's standard but I have access to a 302mm Newtonian telescope and am working on attaching the camera somehow, See "I stayed up late (and cheated)" also in my Gallery. I envy him his rig, Toooo!
Ron

[Inspeqtor]

Derry,

I just ruined my keyboard drooling all over the place looking at your scopes!

Any chance you would rent your scopes out cheap? <grin> just kidding....
I would not want to do anything to cause harm to your great equipment.

Thank you for showing us your equipment! :D

[Inspeqtor]

Ron,

Your moon shots are also very good! :)

[Danudin]

I see a distinct co-relation to the initial thread.

After a storm threatened last night I was surprised to see around 11pm that the skies were crystal clear so braved the cold (18%Celcius) and went out to have a look, and was blown away by the number of stars visible. Ducked in and grabbed the camera and took some shots. Jumped into PSE5 this morning and saw what looked like Your little dipper, (what is it doing down here I thought?) so used some of the enhancement tools in PSE5 to have a better look - THEN I was really blown away. I will give the details of the one photo that I have attached DSC-0441.NEF which I saved as

1. Ex Cam Enhance Aquickfix.jpg (Same as 1. above except selected Enhance then quick fix).
2. Stars Auto Edit.jpg (After clicking Auto as opposed to default when importing into the editor), and
3. Stars Ex Camera.jpg (As the NEF file appears on my monitor),

Details

Date: October 22 2008 11.11pm (Local)
Color Mode RGB
Bit Depth 16 Bit (NEF Only)
Exposure 13 Seconds
F/stop f/5.6
ISO 200
Meter Mode Partition


Could someone please explain what the differences I see in the three jpegs mean, although the 1st jpg shows the clearly visible stars, the second gives a better overall feeling of what encouraged me to get the camera and take some shots. BUT I DID NOT SEE what the 3rd photo shows (Wish I had)

As a side question is that shape that appears to be a dipper in the lower right center of the shot another celestial entity or a dipper ?
Thanks
Ron

[Inspeqtor]

Ron,

I am by no means an expert on celestial items at all. It does appear to me you may be seeing the little dipper. I just got home from work this morning at 2:00am. When I got home I noticed how clear the sky is, and I was seeing the little dipper quite plainly. When I got inside and checked the forum to find your question, I knew I had to go back out side and take more shots. It is getting cold here as fall is now here. The temperature right now is 38 deg Fahrenheit (3 Celsius). I put on my winter coat and went out and braved the cold just for you :D

In the second shot I free handed the lines to show you what I believe the little dipper is supposed to represent.

Sorry I can't answer your other questions. I do hope this is some help to you. In your 3rd picture it does appear the 3 stars that are in a slight curved row are the base of the little dipper. You should be able to see that in my shots.

Maybe you can answer a question I have. I noticed when you inserted your thumbnails they are side by side. When I do it they are on top of each other. I used the paper clip icon to insert these. Is that what you used?

2848

2849

[Byron Gale]

Unless I completely misunderstand things - I believe it is impossible to see the Little Dipper (Ursa Minor) from Ron's vantage point, given that the end of the handle (or tail, if following the "little bear" mythology) is Polaris -- the North Star.

[Inspeqtor]

Byron,

I am showing my ignorance of anything celestial. Are you saying the North Star is not visible below the equator?

[Byron Gale]

Charles,

That's how I understand it... Since the North Star is always above the North Pole, once you cross the equator going south, the Earth would be between you and the star.

Likewise, we in the northern hemisphere cannot see southern constellations.

Byron

[Danudin]

Ron,


Maybe you can answer a question I have. I noticed when you inserted your thumbnails they are side by side. When I do it they are on top of each other. I used the paper clip icon to insert these. Is that what you used?

2848

2849

I am not sure on the workings but when I hit the paperclip it brings up the Attachment Manager, then I browse to the correct folder in My Pictures select the photo I want then upload (Takes a time but eventually this is placed in the current attachments bin, One on top of the other, maybe there is a setting for showing these either stacked or side by side. I don't know for sure.

I do appreciate your bravery for tackling what I consider to be KILLER temperatures, it never gets that cold here, and my favoured part of Australia is Darwin where we learn to sleep in 32 degree celcius heat, No winter, summer spring or autumn (Fall) just wet and dry seasons.

The shots are great and although I can see similarities, I see differences too. I will ask some stargazer friends and get back via this thread for clarity, but if there is anyone who can tell me why one shot, when subjected to two different attributes of PSE5 should show such differing scenes I would be really interested.

Ron

[Inspeqtor]

I am not sure on the workings but when I hit the paperclip it brings up the Attachment Manager, then I browse to the correct folder in My Pictures select the photo I want then upload (Takes a time but eventually this is placed in the current attachments bin, One on top of the other, maybe there is a setting for showing these either stacked or side by side. I don't know for sure.

That is exactly what I did, but it put them one on top of the other, not side by side as yours were. I was just curious if you knew for sure how to get them side by side.


I do appreciate your bravery for tackling what I consider to be KILLER temperatures, it never gets that cold here, and my favoured part of Australia is Darwin where we learn to sleep in 32 degree celcius heat, No winter, summer spring or autumn (Fall) just wet and dry seasons.Here in northern Indiana our summers can get up into the 90-95 deg. Fahrenheit (32-35 celsius) with some years will hit 100 (37) but that is rare. In the winters here it will get into the single digits 5-10 degrees (-15 to -12 C). There have been years but again rare I have seen -20 F (-29C)
That is too cold for me!


The shots are great and although I can see similarities, I see differences too. I will ask some stargazer friends and get back via this thread for clarity, but if there is anyone who can tell me why one shot, when subjected to two different attributes of PSE5 should show such differing scenes I would be really interested.

RonHopefully someone else can answer that question for you!

[Derry]

I have found while star gazing and looking at my astro photos the smallest adjustment in PSE can offer big differences,, stars of only 1 or a .5 difference in magnitude can be lost quickly,, most astro guys will shoot multiple photos of the same image and then stack them all to acquire the best of everything offering the most visibility,,

why one shot would be adjusted in two different settings (visible stars) must have something to do with how the software is filtering or processing in the two different settings,, I never have noticed this but will take a look at some dim star photos and see if I can notice any change on my HD screen while moving from one setting to another,,

Charles, yes there are many constellations in the Southern hemisphere that we never have the luxury to enjoy just as they cannot see ours in the Northern hemisphere,, that bulge (equator) on earths belt is the cause,,

try Microsofts WorldWide telescope download and it will show you what you can see from certain locations on earth,,

Derry

[Danudin]

why one shot would be adjusted in two different settings (visible stars) must have something to do with how the software is filtering or processing in the two different settings,, I never have noticed this but will take a look at some dim star photos and see if I can notice any change on my HD screen while moving from one setting to another,,

Charles, yes there are many constellations in the Southern hemisphere that we never have the luxury to enjoy just as they cannot see ours in the Northern hemisphere,, that bulge (equator) on earths belt is the cause,,

Derry

It seems that you are right up on the astrophotography lark, Derry and if I may be so bold, may I ask for the best way to attach a Nikon D70s DSLR to the 203mm Newtonian telescope I have. It was bought cheaply but gives a great view of the moon that I would like to capture on the camera but feel that manually holding the lens of the camera to the eyepiece may not be the best way of achieving this. Do you have any suggestions?

I won't take it personally when you mention my Equator (Bulge) blocking out the stars from the northern hemisphere but you have encouraged me to try and lose some wheight. (teHee)

Your setup seems ideal for this hobby.

Ron