A tale of two moon pics......

[superatticman]

Good evening all

Relatively new to this astrophotography lark so please forgive me if I'm missing the obvious.

Have a couple of moon pics here. Taken with a Nikon D70 DSLR mounted onto my Skymax 127 and EQ 3-2 mount. Both are as they are with no post processing.

First is pretty acceptable if a tad undercooked. This was taken at ISO 1000 and 1/320th. Took about 10 with these settings and the results were generally the same.

Second is slightly blurred and maybe a tad overcooked. This was taken at ISO 200 and 1/30th. Again took about 10 exposures with similar results.

The reason for this post is that I'm convinced the slower shutter speeds are not producing clear images due what can only be some kind of shake caused by the mechanism. Or maybe the movement of the moon across the Sky even? The moon more fills about 85% of the frame height wise and I'm guessing a magnification of about 50x is present. The camera seems fairly solidly mounted and the EQ3-2 mount is surely more than sturdy enough for the 127 + SLR combo?

I can't perform any pre staged mirror lock up on this particular camera so cannot prove its the 'camera shake'.

Want to get pics of the crescent moon and this requires relatively low shutter speeds. Not had any luck yet due to the issue above

Anyone else experienced this issue at these types of speed?

Thankyou

[Leveye]

Nothing under 1/250th for a moon shot that close. Personally i would not use such a high ISO either. The moon is quite bright use no more than 200

[Langy]

I think the last images I did a couple of nights ago were at ISO 400 and 1/250 second.

It may well have been tweaked a bit in PS CS5 to bring out some more detail and try to sort the lights and darks within the image.

Even with my shake Astromaster 130EQ I've managed to get a lot slower shutter speeds.

If you have some movement in the mount / scope then a bit of off balancing may help to reduce any vibration. A bit of wind can also cause some issues.

I'm like you and don't have the facility for a mirror lockup but with a remote release and firing off a batch of images all at once with the camera on continuous shoot mode seems to produce the images. The mirror movement shouldn't cause too much vibration.

It may sound a bit silly and please don't think that I think you are not thinking of something you already do but when I started I was on my decking which adds to movement, so a good base is also a must.

[Kropster]

When you say 'slower' shutter speeds, do you mean shorter duration?

This is usually termed a 'faster' shutter speed.... i.e. 1/500 is a faster shutter speed than 1/250 etc.

The shorter the duration, the sharper the image should be as this reduces the effect of shake, vibration and atmospherics, simply because you are sampling less of them than at longer duration shutter openings.

[jjqpr]

I am new to this too but I was using 1/250 and iso 100 on my moon shots tonight...seemed to be about right for detail and brightness, of course you're always going to want MORE detail but I don't think a longer shutter speed will help, the moon is SO bright!

[superatticman]

Thanks for that. Yes I've had my mount on the concrete patio. Maybe I should go onto the grass and check the balance with the camera on.

Here's an image I managed to get at ISO 400 1/125th. This is with some post processing ie contrast and sharpening tweak. You can consider it my 'show off' version!

[superatticman]

I am new to this too but I was using 1/250 and iso 100 on my moon shots tonight...seemed to be about right for detail and brightness, of course you're always going to want MORE detail but I don't think a longer shutter speed will help, the moon is SO bright!

But am I right in suggesting that when the moon is at a relatively 'new' stage ie 2 or 3 days old, that shutter speeds will be considerably less than a gibbous or fullish moon? Thats why I'm interested in being able to take shots at less than 1/60th.

And, to throw another factor in, I guess some cameras CCD are more senstive than others? Bearing in mind my D70 is now almost 10 years old.

[Langy]

When you say 'slower' shutter speeds, do you mean shorter duration?

This is usually termed a 'faster' shutter speed.... i.e. 1/500 is a faster shutter speed than 1/250 etc.

The shorter the duration, the sharper the image should be as this reduces the effect of shake, vibration and atmospherics, simply because you are sampling less of them than at longer duration shutter openings.

OP has said that he will need to go to slower shutter speeds with a crescent moon which is quite obvious as the light will be so much lower, therefore 1/200 could well become 1/10 which is slower.

It will be a bit of trial and error but just make sure there is as little chance of movement as possible. Tripod legs spread as far as they will go, sometimes a little extra nudge to force them a little wider. The good thing of being on grass I found is that the feet did into the ground as you make sure the legs are as wide as possible making a more solid base.

You haven't mentioned but a remote release will be essential as the shutter speeds get slower.

[davefrance]

Your main problem would appear to be that your scope is quite slow F11.8 according to FLO so you will need a reasonably slow shutter speed (or higher ISO) to compensate and get more detail in the shadows. This will be even more apparent at crescent when there is far less light being reflected off the moon. You will have to make sure everything is rock solid and use a remote or the timer function on the camera to avoid any shake.  You could also try taking and stacking 10 or 20 in Registax which should improve definition.  

[superatticman]

Invaluable advice so far. Thankyou.

Btw failed to mention I am using a remote shutter release.

One more tedious question! I've heard of Registax and will no doubt be having a play. Does the subject need to be in exactly the same part of the frame when using this? ie my already harrased wallet is anticipating a motor drive?

[Langy]

No it doesn't as it should track the changes. If you have a video though and it's not full frame (like when I record Jupiter) you can use another free software called PIPP that will center the image and even crop the frames. My Juputer video can go from over 1GB to about 30MB as the subject is so small compared to the original video size.

It's all free and not big software so have a play, there are some youtube videos about to help, they don't answer all the questions but get you started. I can only do the basics and have a lot to learn with it.

[superatticman]

Your main problem would appear to be that your scope is quite slow F11.8 according to FLO

I think that has probably explained why my shutter speeds are less than than others are using on here. All those with Newtonians maybe

[Langy]

Still getting my head around things but I believe the longer focal lengths 1500mm for yours are idea for planetary viewing etc.but the shorter focal lengths are more geared to AP. It will also make sense as to why you pickup more vibration being so long, a bit like sticking a 500mm lens on your DSLR compared to a 50mm and hand holding them both.

I think with some trial and error you may well be surprised as to what you can achieve. The video option may make things easier for you though.

[Kropster]

OP has said that he will need to go to slower shutter speeds with a crescent moon which is quite obvious as the light will be so much lower, therefore 1/200 could well become 1/10 which is slower.

It will be a bit of trial and error but just make sure there is as little chance of movement as possible. Tripod legs spread as far as they will go, sometimes a little extra nudge to force them a little wider. The good thing of being on grass I found is that the feet did into the ground as you make sure the legs are as wide as possible making a more solid base.

You haven't mentioned but a remote release will be essential as the shutter speeds get slower.

Sorry... I misinterpreted the original post.

I am not sure about a crescent Moon needing more exposure though.

The illuminated part of the Moon will be smaller, but still as brightly lit... so won't the highlight brightness will be about the same?

[Langy]

Sorry... I misinterpreted the original post.

I am not sure about a crescent Moon needing more exposure though.

The illuminated part of the Moon will be smaller, but still as brightly lit... so won't the highlight brightness will be about the same?

Yes thinking about it they should be. After all we only see it so bright on a full moon because it is so big. The reflective sunlight on the surface should be just the same brightness.

[superatticman]

No video capability on my D70! Was one of the first prosumer DSLR cameras on the market.

Out of interest are there any reasonably priced  'prosumer' DSLRs on the 2nd hand market that include the mirror lock up function which then allows exposures to be taken? Mine does the lock up but only to clean the CCD.

[glappkaeft]

No video capability on my D70! Was one of the first prosumer DSLR cameras on the market.

 

Out of interest are there any reasonably priced  'prosumer' DSLRs on the 2nd hand market that include the mirror lock up function which then allows exposures to be taken? Mine does the lock up but only to clean the CCD.

The Canon 1000D and every Canon in the hundred series from 350D (if not earlier) has it out of the box.

[superatticman]

Seems a used 1000D is a popular 'budget' choice for AP. And the 1100D gives similar performance but with 720p video thrown in too. Guess that would be useful for the planets.

Was hoping to stay with my Nikon, have a couple of lenses, flashgun etc but it does look like Canon are head and shoulders the best for AP?

Sorry for endless questions, but can a webcam do anything that a DSLR with video can't? I guess if I was to switch toa  Canon with 720 video,  part of the expense incurred could be written off by not needing to worry about buying a webcam.

[Langy]

The Canon 1000D and every Canon in the hundred series from 350D (if not earlier) has it out of the box.

300D doesn't.

[Kropster]

Seems a used 1000D is a popular 'budget' choice for AP. And the 1100D gives similar performance but with 720p video thrown in too. Guess that would be useful for the planets.

Was hoping to stay with my Nikon, have a couple of lenses, flashgun etc but it does look like Canon are head and shoulders the best for AP?

Sorry for endless questions, but can a webcam do anything that a DSLR with video can't? I guess if I was to switch toa  Canon with 720 video,  part of the expense incurred could be written off by not needing to worry about buying a webcam.

Webcams are favoured for planetary over dslrs.

I think this may be due to the smaller pixel size effectively giving higher resolution over that from the larger sensor of a dslr.

The larger dslr sensor is of no value as the image is usually small enough to fit on the webcam sensor.

...but I may stand to be corrected by somebody with a better grasp of the situation.