Alrighty, let's try this again - Moon 06/05/09

The skies were reasonably clear tonight, so thought I would give the moon a try again. Spent a fair amount of time outside trying different shutter speeds, f-stops, adjusting focus, etc. This is the best that I was able to come up with, adjusted in PS7. I just couldn't get a nice sharp image to start from.

Al

HTTP response: 404 | MIME changed to 'image/gif' | Byte size: ZERO | PHOTOBUCKET ERROR IMAGE

It's still soft Chopper . Have you tried a different lens for comparison ?? Are you using the Tamaron in your signature ?

Celestron wrote in post #8058786
It's still soft Chopper . Have you tried a different lens for comparison ?? Are you using the Tamaron in your signature ?

Hi Ron. Yes, I am using the Tamron 75-300 that is in my signature. I don't have access to another long lens right now for comparison. This lens is the one that came with the camera when I bought it from a pawn shop. If it turns out it isn't any good for this type of photography, then no big deal. It will probably turn out to be user error though...

Al

Al,

In the other thread I said that I had seen a very sharp image of the Moon with a 70-300 lens - turns out it was on a tripod.

John

Peerie wrote in post #8060310
Al,

In the other thread I said that I had seen a very sharp image of the Moon with a 70-300 lens - turns out it was on a tripod.

John

Hi John,

I was set up on a tri-pod, using mirror lock-up, remote release and connected to my laptop using DSLR Remote so I could view the results right away. The darned thing looked sharp in the view finder, just not in the picture.

I started taking pictures from full infinity focus, then slowly adjusting the focus a hair for each subsequent shot until the images became totally blurry again, as viewed on my laptop. I then tried auto focus setting the camera to use the center spot only for AF. Next, I set the center focus spot on the bright curve of the moon, and the black of the sky. Looked fine in the view finder, but blurry image resulted.

I used a variety of shutter speeds (up to and including 1/500) along with varying the f-stop. ISO was left at 100.

Al

This worked well for me , ISO 100, f7.1, 1/200sec @300mm on tripod. Give that a try. Also try to shoot when the moon is high so you don't get as much haze.

Is it possible for a lens to just not focus at longer distances, but works fine on closer objects? The picture of the bird in the other post would have been around 20-25 feet away, so would not be in the infinity range for focusing.

Al

Chopper Al wrote in post #8060439
.... I set the center focus spot on the bright curve of the moon, and the black of the sky. Looked fine in the view finder, but blurry image resulted.

That would have been my suggestion. I only use manual focus when forced to do so.

Chopper Al wrote in post #8060951
Is it possible for a lens to just not focus at longer distances, but works fine on closer objects? The picture of the bird in the other post would have been around 20-25 feet away, so would not be in the infinity range for focusing.

Al

How solid is your tripod. Is it a really heavy duty one on the order of a Gitzo? My big Induro is broken currently and I have found that my lightweight Velbon Sherpa is simply not solid enough. Even a breeze can induce significant vibration when we are wanting sharpness down to the pixel level. Draping small sandbags or heavy shipping blankets over the tripod legs when they are splayed wide can sometimes help to dampen vibration. I also use a couple bungee cords from the center post to an earth anchor (actually an aircraft tie-down that looks like a giant corkscrew that is screwed into the ground). I plan to try out a Bahtinov mask for manual focusing when I use my 400 mm lens with either or both of my teleconverters attached. I have heard that it is the best thing since sliced bread.

Bill Boehme wrote in post #8073697
That would have been my suggestion. I only use manual focus when forced to do so.

How solid is your tripod. Is it a really heavy duty one on the order of a Gitzo? My big Induro is broken currently and I have found that my lightweight Velbon Sherpa is simply not solid enough. Even a breeze can induce significant vibration when we are wanting sharpness down to the pixel level. Draping small sandbags or heavy shipping blankets over the tripod legs when they are splayed wide can sometimes help to dampen vibration. I also use a couple bungee cords from the center post to an earth anchor (actually an aircraft tie-down that looks like a giant corkscrew that is screwed into the ground). I plan to try out a Bahtinov mask for manual focusing when I use my 400 mm lens with either or both of my teleconverters attached. I have heard that it is the best thing since sliced bread.

Thanks Bill. I inherited my tripod from my late father-in-law. It says 'Focal' on one of the legs and the head (no model number though). It has a quick release head and bubble level on it. I did notice that even with all the adjustments tightened down, there is still some play in the head. I am wondering if one of the camera stores would allow me to mount my camera on one of their better tripods and take some photos to see if that would make a difference?

Al

Chopper Al wrote in post #8074149
Thanks Bill. I inherited my tripod from my late father-in-law. It says 'Focal' on one of the legs and the head (no model number though). It has a quick release head and bubble level on it. I did notice that even with all the adjustments tightened down, there is still some play in the head. I am wondering if one of the camera stores would allow me to mount my camera on one of their better tripods and take some photos to see if that would make a difference?

Al

I think I may have (or did have) a Focal tripod from about thirty yeas ago. Is it made with "U" channel aluminum (as opposed to being tubular)? I discovered that one of the cam locks was defective and allowed that section of the leg to slowly collapse. The pan/tilt head on the tripod had some free play even after being tightened down.

With a typical pan/tilt head or even a ball head,the system is off balance, especially when looking near the zenith (i.e., straight up) which will just tend to aggravate any tripod problems. I bought a Wimberly Sidekick for bird photography which is a gimbal mount that allows balancing the camera and lens and have found that it is also perfect for astrophotography if you do not have an astronomical telescope to piggy-back the camera onto.

Bill Boehme wrote in post #8074838
I think I may have (or did have) a Focal tripod from about thirty yeas ago. Is it made with "U" channel aluminum (as opposed to being tubular)? I discovered that one of the cam locks was defective and allowed that section of the leg to slowly collapse. The pan/tilt head on the tripod had some free play even after being tightened down.

With a typical pan/tilt head or even a ball head,the system is off balance, especially when looking near the zenith (i.e., straight up) which will just tend to aggravate any tripod problems. I bought a Wimberly Sidekick for bird photography which is a gimbal mount that allows balancing the camera and lens and have found that it is also perfect for astrophotography if you do not have an astronomical telescope to piggy-back the camera onto.

Hey Bill,

Just checked, and the legs are rectangular tubes (not 'U' channel). The tripod worked okay for doing some basic video stuff, but I guess it just won't cut it for more precise type work.

Al

Chopper Al wrote in post #8060439
Hi John,

I was set up on a tri-pod, using mirror lock-up, remote release and connected to my laptop using DSLR Remote so I could view the results right away. The darned thing looked sharp in the view finder, just not in the picture.

I started taking pictures from full infinity focus, then slowly adjusting the focus a hair for each subsequent shot until the images became totally blurry again, as viewed on my laptop. I then tried auto focus setting the camera to use the center spot only for AF. Next, I set the center focus spot on the bright curve of the moon, and the black of the sky. Looked fine in the view finder, but blurry image resulted.

I used a variety of shutter speeds (up to and including 1/500) along with varying the f-stop. ISO was left at 100.

Al

It sounds like you are doing everything right. All I can suggest is try a quarter or crescent moon and use the terminator (shadow line) on the moon as your focal point. You should get good sharp contrast on crater rims end mountain ranges to focus on. Less light too, which can make focus easier.

Baz.

I have one other thought -- even though you are locking the mirror up, the shutter itself can cause a considerable amount of vibration that can last for several seconds if the tripod is not sturdy enough. There is a way to get around the shutter vibration using what is known as the "hat trick" technique. This works best in a very dark location -- here is what you do:

1. Set the camera for bulb exposure.
   
2. Use a hat or something similar to cover the objective lens.
   
3. With the remote shutter cable, open the shutter.
   
4. Wait about ten seconds for all vibrations to settle out.
   
5. Very quickly uncover and then cover the lens with the hat making sure that the "hat" does not touch the lens.
   
6. Release the shutter.