All Images Blurry

[Garabaldi15]

DSC_1932.NEFHi All,

I'm hoping to find someone who might be able to help with an issue with all my images coming out blurry.

As a little background I've recently purchased a Celestron 5SE scope in the hope to image some brighter objects (i.e. moon, orion nebula, other solar planets etc). I already own a Nikon D3100 camera and I bought a 2" adaptor and t-ring to attach the camera to the scope as a prime lens.

I've played around for about 10 nights now looking at different camera settings and different objects and have yet to get an image that is sharp. I can focus the image through the view finder/live image option on the camera and it looks sharp even when zooming in but after taking the image it's always blurry. I've attached an example image; it's probably a little under exposed.

In terms of settings on the D3100 I've tried ISO 100/200 (and some others to experiment) and various exposures between 1/250 and 1/50. I have also tried bulb with a black card but I can't swing it out of the way and back again quick enough to not just get an exceptionally over exposed photo (I tried this thinking the issue maybe vibration). I've also tried using multishot to capture 10-20 issues at one time to reduce vibration. I've also tried a remote shutter to avoid touching the camera.

Are there any obvious suggestions of what I could be doing wrong to not get the sharp image that appears in the viewfinder?

Thanks in advance!

 

DSC_1932.NEF

Edited April 18, 2021 by Garabaldi15

[rickwayne]

Nothing obvious springs to mind. You could overexpose and look for stars in the image, see if they're soft or jump-around lines, might help you see if it's vibration or something else. You could also try using much higher ISOs to enable very short exposure times.

Another dodge would be to try it with a terrestrial object during the day, when you  can use super-fast shutter speeds even at lower ISOs, and really nail the focus.

Finally, you could make or purchase a  Bahtinov mask and use it to get stars absolutely spot-on focused, and work from there.

[Davey-T]

Hi and welcome to SGL.

Just looks out of focus, does your camera have mirror lock facility.

Dave

[Garabaldi15]

4 hours ago, Davey-T said:

Hi and welcome to SGL.

Just looks out of focus, does your camera have mirror lock facility.

Dave

Hi Dave,

it does but only for cleaning you can’t take photos with the mirror lock on unfortunately.

Thanks

[Garabaldi15]

5 hours ago, rickwayne said:

Nothing obvious springs to mind. You could overexpose and look for stars in the image, see if they're soft or jump-around lines, might help you see if it's vibration or something else. You could also try using much higher ISOs to enable very short exposure times.

Another dodge would be to try it with a terrestrial object during the day, when you  can use super-fast shutter speeds even at lower ISOs, and really nail the focus.

Finally, you could make or purchase a  Bahtinov mask and use it to get stars absolutely spot-on focused, and work from there.

Thank you for the suggestions I’ll certainly try a higher iso and look at getting it out during the day. 
I’ve not used a Bahtinov before but will take a look.

 

thanks,

chris

[JSeaman]

I have only had a play with the JPG quickly so you can definitely do more but this is with a bit of sharpening, a despeckle, convert to B&W to remove colour artefacts, shadows/highlights to bring out a bit more of the shadow, crop to suit

Stacking a bunch of short images can help even with the moon, assuming you are using a tripod then it shouldn't be vibration at those shutter speeds. Personally I would be keeping the ISO at 100 or 200 for noise control, you should be able to go up as high as f/11 with that normally. 

 

The viewfinder image is smaller which always looks better, you can hopefully see that in the below:

[ollypenrice]

This is an optical viewfinder? When you look through the viewfinder the eye is responding almost instantaneously to the incoming light. The atmospherically induced turbulence (the seeing) is causing the image to move around slightly but the eye sees it at any one instant in that movement, so it appears sharp. When you take an exposure of a fraction of a second, any movement during that time is recorded and appears as blur. I think it is inevitable that the eye view will be sharper than a single exposure. The ultra-sharp lunar images you are used to seeing on forums are made by taking video footage during which there will be a decent number of lucky moments in which the seeing was good enough to allow for a particularly sharp capture. These lucky moments are then selected and combined. 

A digital photo is a set of measurements, one per pixel. It is always the case that the most accurate way to measure something is to make many measurements and take an average. So it is with stacking multiple sub exposures.

Do you not have a video mode? If not, even a basic, inexpensive fast frame camera will beat a stills-only camera for lunar imaging.

Olly

Edited April 19, 2021 by ollypenrice
typo

[Garabaldi15]

On 19/04/2021 at 08:12, JSeaman said:

I have only had a play with the JPG quickly so you can definitely do more but this is with a bit of sharpening, a despeckle, convert to B&W to remove colour artefacts, shadows/highlights to bring out a bit more of the shadow, crop to suit

Stacking a bunch of short images can help even with the moon, assuming you are using a tripod then it shouldn't be vibration at those shutter speeds. Personally I would be keeping the ISO at 100 or 200 for noise control, you should be able to go up as high as f/11 with that normally. 

 

The viewfinder image is smaller which always looks better, you can hopefully see that in the below:

Thank you, it does look much improved.

I’ll try taking a few multi shots and stacking them to see how it compares!

[alacant]

On 18/04/2021 at 22:55, Garabaldi15 said:

the D3100

Hi

The NEF will always look washed out until you convert it into a form which can then be processed.

DarkTable does a good job of getting raw data into processable form without losing any of it along the way. After that, you can process it to make it look however you like.

Cheers