Can't achieve sharp focus with camera

[Joe84]

Hello there, 

I've started trying to take photos through my telescope. Its not an ideal scope for this but non the less its what i have and i am trying to make the best of it.

So using my telescope it seems fairly sharp with my eye, but when taking photos i just cant seem to get it sharp enough! 

I've got a Powerseeker 114eq - with this prime focus isnt possible with a dslr, so im using a barlow to get an image. I have 3 barlows varying in quality but all suffer the same problem.

I can focus with plenty of room on either side of where i would expect sharp focus to be, but never find actual crispness. neither via live mode on the camera nor once the picture is taken.

Im fairly new and have never collimated my scope. is that related to focus? i mean i can see through it ok as it seems sharper to my eye than when i try to take photos but it could just be my eye thinking its sharp.

I have a Baader Zoom Barlow and a Canon DSLR, both fairly quality items. so im left with the telescope being the issue.

Any ideas or advice would be great!

 

Thanks

Joe

 

I have included an image of the moon i took, it has been sharpened a bit in post but it still shows a softness. i have included another photo using a different barlow with the purple fringing as it more clearly shows the lack of sharpness. 

Moon Baader Full 2.tif IMG_2402.CR2

[Cornelius Varley]

@Joe84 Can you upload the image in either .jpg or .png format so that it can be displayed in the browser.

[Nicola Hannah Butterfield]

15 hours ago, Cornelius Varley said:

@Joe84 Can you upload the image in either .jpg or .png format so that it can be displayed in the browser.

I did look at the pictures, but obviously can't repost without permission, the cr2 file from the info, was taken 26/8/20 20:57 1/10th's ISO 100  pattern metering, shows a half moon, alot of blue/cyan C.A. upper right of the moon, on that date and time from my location in West Yorkshire would have put it 12 degrees above the horizon, so quite low a lot of atmosphere, the slow shutter will not have helped, but in terms of sharpness, not much worse than I can seem to achieve at the same altitude.

The Tiff, taken 18/11/20 18:06 1/100th ISO 1600 metering pattern, again from my location, at 18:00 was just over 3 degrees, so very difficult at best, Sharpness is quite good given it very low altitude, and high ISO no sign of heavy C.A.

What my conclusions would be, are to try to shoot in manual mode for the exposure, take several shots at different speeds, and try to shoot the moon at higher altitudes, judging from the differance in C.A. I would suggest the barlow in the tiff is better than that is the cr2.

For the OP to compare, I shot this the day after the tiff image, so much higher, but about the same as the cr2, 19/11/20 16:54 ISO 200 1/320th Skywatcher P200D f5, only edit is a crop, I only got this because I was doing a series of test shots, but it does show the tiff image is not far away, when you consider the problems of low altitude imaging, nor can I work out the true focal lengths and magnification, my original is 20x as it is shot at prime focus.

 

If you look at the east of the moons edge (as viewing the image) you can see air convection currents distorting the edge, but they could be within the scope as I said I was only doing a test and the scope hadn't cooled down fully,.

Edited November 20, 2020 by Nicola Hannah Butterfield

[Joe84]

21 hours ago, Cornelius Varley said:

@Joe84 Can you upload the image in either .jpg or .png format so that it can be displayed in the browser.

Hi,

Sorry should have uploaded as jpeg but didnt think about it at the time. Here are the two images again. 

[Joe84]

5 hours ago, Nicola Hannah Butterfield said:

I did look at the pictures, but obviously can't repost without permission, the cr2 file from the info, was taken 26/8/20 20:57 1/10th's ISO 100  pattern metering, shows a half moon, alot of blue/cyan C.A. upper right of the moon, on that date and time from my location in West Yorkshire would have put it 12 degrees above the horizon, so quite low a lot of atmosphere, the slow shutter will not have helped, but in terms of sharpness, not much worse than I can seem to achieve at the same altitude.

The Tiff, taken 18/11/20 18:06 1/100th ISO 1600 metering pattern, again from my location, at 18:00 was just over 3 degrees, so very difficult at best, Sharpness is quite good given it very low altitude, and high ISO no sign of heavy C.A.

What my conclusions would be, are to try to shoot in manual mode for the exposure, take several shots at different speeds, and try to shoot the moon at higher altitudes, judging from the differance in C.A. I would suggest the barlow in the tiff is better than that is the cr2.

For the OP to compare, I shot this the day after the tiff image, so much higher, but about the same as the cr2, 19/11/20 16:54 ISO 200 1/320th Skywatcher P200D f5, only edit is a crop, I only got this because I was doing a series of test shots, but it does show the tiff image is not far away, when you consider the problems of low altitude imaging, nor can I work out the true focal lengths and magnification, my original is 20x as it is shot at prime focus.

 

 

If you look at the east of the moons edge (as viewing the image) you can see air convection currents distorting the edge, but they could be within the scope as I said I was only doing a test and the scope hadn't cooled down fully,.

Hi Thanks for your reply!

 

These are two examples that i ha to hand, but all my images tend to be soft in terms of sharpness. I agree it was quite moist humid albeit cold when the Baader photo was taken and it is a much better quality barlow than the other one i used. I wanted to show both as i feel the same problem persisted with lack of sharpness.

So you think it could be related to the moon being low on the horizon? I think that could be an issue, but i never manage sharpness so im hoping im missing something like colimation. 

 

I have included another shot just to show again a softness. This hill top is about 1km away or more and shows the same issue. Do you use a reflector telescope?

 

[Cornelius Varley]

23 hours ago, Joe84 said:

I've got a Powerseeker 114eq - with this prime focus isnt possible with a dslr, so im using a barlow to get an image. I have 3 barlows varying in quality but all suffer the same problem.

The Powerseeker 114/900 has a spherical mirror rather than a parabolic, so sharpness tends to drop off as you get closer to the edge of the mirror. Your barlow lenses might be achromatic, the first image show a bit of chromatic aberration (blue fringing) along the limb. Normally a number of shots or a video is taken and then stacked in Registax to produce the final image. A single shot might exhibit some atmospheric disturbances which will be reduced with a stacked video/images.

[Joe84]

22 minutes ago, Cornelius Varley said:

The Powerseeker 114/900 has a spherical mirror rather than a parabolic, so sharpness tends to drop off as you get closer to the edge of the mirror. Your barlow lenses might be achromatic, the first image show a bit of chromatic aberration (blue fringing) along the limb. Normally a number of shots or a video is taken and then stacked in Registax to produce the final image. A single shot might exhibit some atmospheric disturbances which will be reduced with a stacked video/images.

Thanks for the quick reply.

 

Ive stacked before as ive done some astrophotography and used a stacker for that. I'll give RegiStax a try and see if it helps. Im so used to getting pin sharp focus with my camera lenses that maybe my expectations were too high?

I'll keep trying and wait for better conditions to see what i can get, really has been so damp and the air is thick recently.

Thanks again!

[Tiny Clanger]

Looking at your daytime photo makes me wonder if internal reflections are degrading the image : have you considered flocking the inside of the telecope tube ? It's not expensive, FLO sell black sticky backed flock sheets for this purpose, plenty of how to vid.s for the process . It's on my to do list . A home made dew cap (like a camera lens hood) might cut out some stray light too.

Are you using a remote to release the camera shutter ? If not, try using the shutter delay to let any vibrations die down . Finally, I'm not familiar with your 'scope, but know that on the Celestron 114 eq (jones bird ) I inherited , the focus tube tends to creep under the weight of a DSLR body .

Edited November 21, 2020 by Tiny Clanger
stupid spelling

[Nicola Hannah Butterfield]

On 20/11/2020 at 15:15, Joe84 said:

Hi Thanks for your reply!

 

These are two examples that i ha to hand, but all my images tend to be soft in terms of sharpness. I agree it was quite moist humid albeit cold when the Baader photo was taken and it is a much better quality barlow than the other one i used. I wanted to show both as i feel the same problem persisted with lack of sharpness.

So you think it could be related to the moon being low on the horizon? I think that could be an issue, but i never manage sharpness so im hoping im missing something like colimation. 

 

I have included another shot just to show again a softness. This hill top is about 1km away or more and shows the same issue. Do you use a reflector telescope?

 

I use a Skywatcher 200P which is an 8" reflector focal length 1,000mm giving an f stop of f5, most of my images with it are at prime focus, which can be achieved with this scope, the barlow which I have used isn't great it is the kit barlow.

This is the very first image I took with it 10/01/20, more to test the prime focus as to its sharpness, but as you will seem it isn't to dissimilar to your sheep image. This was taken exif says 16:41 suspect that was bst, so more like 15:41, not sure how far the windmill is a good few miles.

This is the very first moon shoot, hazy cloud.

This is what I got 2 days later, single frame 1/200th f5 1,000mm iso 100

Then this towards the end of the phases

Which shows a similar softness to your crescent moon.

I have shot the moon through the barlow and even eyepiece projection exposure for this was 1/50th iso 12.800, effective f/l was 18m at f90 the c.a. you see towards the bottom I think was the kit barlow lens.

Non of them are very sharp, so practise with the better barlow you have, do different exposures in manual mode, focus in and out using the 10x live view as sharp as it can been, live view is never as sharp as the final image, and has been said, remote shutter or timer and if possible mirror lock up.

 

Edited November 22, 2020 by Nicola Hannah Butterfield
spelling

[rickwayne]

Are you at the limit of your focuser's travel? It's not uncommon for Newts built for visual use to be unable to achieve focus with a camera. Some folks have even resorted to cutting the tube so they can shorten it by a few centimeters!

[Nicola Hannah Butterfield]

8 hours ago, rickwayne said:

Are you at the limit of your focuser's travel? It's not uncommon for Newts built for visual use to be unable to achieve focus with a camera. Some folks have even resorted to cutting the tube so they can shorten it by a few centimeters!

OP already established that.

On 19/11/2020 at 16:27, Joe84 said:

 

I've got a Powerseeker 114eq - with this prime focus isnt possible with a dslr, so im using a barlow to get an image. I have 3 barlows varying in quality but all suffer the same problem.

 

[Adam J]

On 19/11/2020 at 16:27, Joe84 said:

Hello there, 

I've started trying to take photos through my telescope. Its not an ideal scope for this but non the less its what i have and i am trying to make the best of it.

So using my telescope it seems fairly sharp with my eye, but when taking photos i just cant seem to get it sharp enough! 

I've got a Powerseeker 114eq - with this prime focus isnt possible with a dslr, so im using a barlow to get an image. I have 3 barlows varying in quality but all suffer the same problem.

I can focus with plenty of room on either side of where i would expect sharp focus to be, but never find actual crispness. neither via live mode on the camera nor once the picture is taken.

Im fairly new and have never collimated my scope. is that related to focus? i mean i can see through it ok as it seems sharper to my eye than when i try to take photos but it could just be my eye thinking its sharp.

I have a Baader Zoom Barlow and a Canon DSLR, both fairly quality items. so im left with the telescope being the issue.

Any ideas or advice would be great!

 

Thanks

Joe

 

I have included an image of the moon i took, it has been sharpened a bit in post but it still shows a softness. i have included another photo using a different barlow with the purple fringing as it more clearly shows the lack of sharpness. 

Moon Baader Full 2.tif 72.92 MB · 14 downloads IMG_2402.CR2 16.3 MB · 7 downloads

Not coming to a sharp focus is most likely low order spherical aberration from the spherical mirror. Honestly this scope is just not designed for imaging at all. If you want to image and get sharp results you should buy a 130pds that has a parabolic mirror and a focuser optimized for prime focus is making. 

[Joe84]

21 hours ago, Adam J said:

Not coming to a sharp focus is most likely low order spherical aberration from the spherical mirror. Honestly this scope is just not designed for imaging at all. If you want to image and get sharp results you should buy a 130pds that has a parabolic mirror and a focuser optimized for prime focus is making. 

Yes i'm starting to realise this telescope while nice for eye observations just isnt up to the task of astrophotography. The mount is shocking and really doesnt like a camera added to it. Im going to keep trying for a bit and research which scope would suit my needs better. as with most things itll prob end up being a lot more expensive as is life haha

 

thanks for replying 

 

[Joe84]

On 20/11/2020 at 23:48, rickwayne said:

Are you at the limit of your focuser's travel? It's not uncommon for Newts built for visual use to be unable to achieve focus with a camera. Some folks have even resorted to cutting the tube so they can shorten it by a few centimeters!

plenty of travel as using a barlow to focus, the barlow is very good quality so i think its just the imaging limitations to my fairly cheap telescope.

 

thanks for your reply

[Joe84]

On 20/11/2020 at 17:54, Nicola Hannah Butterfield said:

I use a Skywatcher 200P which is an 8" reflector focal length 1,000mm giving an f stop of f5, most of my images with it are at prime focus, which can be achieved with this scope, the barlow which I have used isn't great it is the kit barlow.

This is the very first image I took with it 10/01/20, more to test the prime focus as to its sharpness, but as you will seem it isn't to dissimilar to your sheep image. This was taken exif says 16:41 suspect that was bst, so more like 15:41, not sure how far the windmill is a good few miles.

 

This is the very first moon shoot, hazy cloud.

 

This is what I got 2 days later, single frame 1/200th f5 1,000mm iso 100

 

Then this towards the end of the phases

Which shows a similar softness to your crescent moon.

I have shot the moon through the barlow and even eyepiece projection exposure for this was 1/50th iso 12.800, effective f/l was 18m at f90 the c.a. you see towards the bottom I think was the kit barlow lens.

 

Non of they are very sharp, so practise with the better barlow you have, do different exposures in manual mode, focus in and out using the 10x live view as sharp as it can been, live view is never as sharp as the final image, and has been said, remote shutter or timer and if possible mirror lock up.

 

some great photos there! the shot of the moon in sharp focus is what i'd love to be able to get.

 

i am very new at this and skies are so rarely clear where i am i struggle to get enough practice and when it is clear im never set up or ready so rush about trying to get things together haha

 

Im going to keep trying and hope i can improve with this scope, then as time goes by i'll look in to buying one thats more suited to astrophotography rather than viewing by eye.

 

thanks a lot for your input!

 

included a photo of a view from my house not too dissimilar to yours haha, but also highlights a big difference in air quality can make to a clear image. This was with a phone taken over the eyepeice, but sometimes seems sharper than when my dslr is set up :S

 

[Nicola Hannah Butterfield]

As @Adam Jsaid the skywatcher pds range are not bad, basically the same as my p version but more suited to photography, and yes air quality is very important to sharper images.

There will be a half moon tonight virtually due south about 18:00, but if you can try mid week the moon will be higher, but later so the air may have had more time to settle, the thing is you never know till the day.

[Joe84]

On 22/11/2020 at 12:16, Nicola Hannah Butterfield said:

As @Adam Jsaid the skywatcher pds range are not bad, basically the same as my p version but more suited to photography, and yes air quality is very important to sharper images.

There will be a half moon tonight virtually due south about 18:00, but if you can try mid week the moon will be higher, but later so the air may have had more time to settle, the thing is you never know till the day.

Just a follow up, I had a bit of luck last night where my problem disappeared and then reappeared after i did something which made me figure it out.

 

my telescope is in the spare room next to the radiator. as i open the window to take shots it gets cool air on it and softened my photos. So i took my telescope outside and tried again. Heres what i managed. a big improvement!

 

[Nicola Hannah Butterfield]

@Joe84you have also managed to capture the Lunar X and V, which has really only been visible twice this year during the hours of darkness from the UK

So it does seem more a thermal or air quality issue than equipment. T slight C.A. is likely to be from the barlow.

Edited November 24, 2020 by Nicola Hannah Butterfield

[Joe84]

On 24/11/2020 at 09:19, Nicola Hannah Butterfield said:

@Joe84you have also managed to capture the Lunar X and V, which has really only been visible twice this year during the hours of darkness from the UK

I would never have known that, thanks for pointing it out to me!