First image on astro modified camera, is this what I should expect to see?

[LaurenceT]

Just dipping my toes into astrophotography and so my knowledge and experience is very limited, last night was the first time with my astro modified camera.

Gear:

Sony A5000 full spectrum astro modified camera

Samyang 135mm f2

Ioptron Sky Tracker Pro

Bortle 5 area (Surrey)  20 subs, 2 minute exposures, stacked in Sequator and processed in DXO3 and Lightroom 6, no darks etc. Target: Vega

The first image was flooded with red light, I was expecting that. I'm showing here the final processed image. I know that Vega is supposed to be a blue star when viewed with an unmodified camera, is my image what I can expect with a full spectrum modification?

[powerlord]

it's not gonna make a lot of difference for stars imho. Usually modified just removes the IR filter, which has the side effect that we want of letting in the h-alpha more.

So - you need to point it at something thats got lots of h-alpha.

At the moment that means something like North America nebula which you'l see in the same forum myself and another op have posted pics of.

What you should then see is a lot of of the nebulosity vs non modifed camera. If it was earlier in the year M42 is the best target to demostrate the difference.

As it's full spectrum though I believe you should be putting an UV/IR filter on for astro use otherwise you get star bloat - which I think there is some of in your image ?

[carastro]

That's pretty good for a first image.  

Carole 

[alacant]

On 13/06/2021 at 12:57, LaurenceT said:

what I can expect

Hi

Difficult to say because we don't know how you processed it; Vega looks green with a red halo.

That maybe because you missed focus and/or don't have an ir filter on the lens. You could fit a 77mm front filter (they're quite cheap); I'm not sure there are clip or in-adaptor filters for Sony.  If it helps and you have no other specific uses for the full spectrum, you could consider refitting the filter in the camera as I think the front mounted filter may cause other issues for astro stuff. 

Cheers and HTH

Edited June 15, 2021 by alacant

[Grant93]

13 hours ago, powerlord said:

it's not gonna make a lot of difference for stars imho. Usually modified just removes the IR filter, which has the side effect that we want of letting in the h-alpha more.

So - you need to point it at something thats got lots of h-alpha.

At the moment that means something like North America nebula which you'l see in the same forum myself and another op have posted pics of.

What you should then see is a lot of of the nebulosity vs non modifed camera. If it was earlier in the year M42 is the best target to demostrate the difference.

As it's full spectrum though I believe you should be putting an UV/IR filter on for astro use otherwise you get star bloat - which I think there is some of in your image ?

Just reading this and thought "oh it must be me"

Yes if you compare the two also, it's a good comparison of the difference of H-alpha picked up between modified and unmodified. (spoiler alert - his is better ).

[malc-c]

Un modified cameras have IR cut filters in them, which restrict the light in the Ha spectrum that as astrophotographers we would like to record.  A fully modified camera typically has all these IR cut filters removed so the sensor received the full wavelength it can detect, in both UV and IR.  Sometimes a piece of "glass" is placed across the sensor to protect it from dust etc.  The drawback when using a full spectrum camera is that you can end up with bloated stars, with a blue edge to them as the sensor records all the wavelengths.  It is therefore advisable to fit a dedicated astro UV/IR filter between the sensor and the subject.  These cut out a lot of the spectrum we don't want, but allow the parts we do, such as Ha, and as a result stars appear more natural when processed.  But as others have said, its nebula and galaxies that really should be the target, not stars, and they have already suggested some targets.    You may find that even without the UV/IR filter, the amount of IR the camera picks up will make for an interesting result.

[LaurenceT]

Thanks for the very useful replies, I shall be investigating using a UV/IR filter. Why would a clip in filter be better than a screw in front mounted filter?

My processing of this image would have fairly "agricultural" when compared to the large amount of processing of astro images I've seen people doing. I come from a background of many years wildlife and macro photography where the post processing required is minimal compared to astro pp. I'm learning Affinity to be able to post process more effectively.

I'm so glad I found this site, it's a very useful resource with helpful members.

[powerlord]

3 hours ago, LaurenceT said:

Thanks for the very useful replies, I shall be investigating using a UV/IR filter. Why would a clip in filter be better than a screw in front mounted filter?

My processing of this image would have fairly "agricultural" when compared to the large amount of processing of astro images I've seen people doing. I come from a background of many years wildlife and macro photography where the post processing required is minimal compared to astro pp. I'm learning Affinity to be able to post process more effectively.

 

I was the same -  been into photography for 35 years... you soon realise AP is a different ball game - think of taking the 'subs' as just getting the raw ingredients for your recipe.

Then it's up to you to make that recipe end up as either a pot noodle or a michellin star meal.

Realising that was what helped me switch up a gear and realise I had to learn more for processing. I use StarTools and Affinity.

Have a look on youtube for affinity tutorials which are very good at showing how to use Affinity with AP.

Filiter wise, if you are in an area with light pollution, if you get a light pollution filter (CLS or UHC ), that will double as an IR/UV filter. 2 burds, 1 stone

stu

[carastro]

Quote

you soon realise AP is a different ball game - think of taking the 'subs' as just getting the raw ingredients for your recipe.

As some-one who has been imaging for about 10 years now, this is absolutely spot on.  Capture is only half the job, you can spend as much time again, sometimes more on the post=processing and post-processing also takes a long time to learn.  

If you have been a photographer for a long time you may be familiar with Photoshop, if so take a look at some of my video tutorials on You Tube for examples.  You can find the links on my website in my Signature. 

Carole 

Edited June 15, 2021 by carastro

[LaurenceT]

41 minutes ago, powerlord said:

I was the same -  been into photography for 35 years... you soon realise AP is a different ball game - think of taking the 'subs' as just getting the raw ingredients for your recipe.

Then it's up to you to make that recipe end up as either a pot noodle or a michellin star meal.

Realising that was what helped me switch up a gear and realise I had to learn more for processing. I use StarTools and Affinity.

Have a look on youtube for affinity tutorials which are very good at showing how to use Affinity with AP.

Filiter wise, if you are in an area with light pollution, if you get a light pollution filter (CLS or UHC ), that will double as an IR/UV filter. 2 burds, 1 stone

stu

Thanks for your reply, I like the cooking analogy.

I can't find any details that a light suppression filter will also block IR and UV, I would be ecstatic if that were the case. Do you have any further information?

[powerlord]

Have a look here.

 

https://astrobackyard.com/light-pollution-filters/

 

You'll find they cut off below 400 (UV), and above 750 or so (IR)

stu

Edited June 15, 2021 by powerlord

[LaurenceT]

6 hours ago, powerlord said:

Have a look here.

 

https://astrobackyard.com/light-pollution-filters/

 

You'll find they cut off below 400 (UV), and above 750 or so (IR)

stu

Having been very disappointed in the past with filters I'm inclined to go with better quality glass but I know that costs money. I've singled out two filters, one clip-in and the other a normal screw-on filter, my choices are somewhat limited by having a Sony APSC full spectrum modified camera.

https://www.cliftoncameras.co.uk/stc-clip-astro-ms-filter/brand-fitting/sony-aps-c

https://www.harrisontelescopes.co.uk/acatalog/explore-scientific-filter-77mm.html

 

 

[Jonny_H]

On 15/06/2021 at 15:25, carastro said:

As some-one who has been imaging for about 10 years now, this is absolutely spot on.  Capture is only half the job, you can spend as much time again, sometimes more on the post=processing and post-processing also takes a long time to learn.  

If you have been a photographer for a long time you may be familiar with Photoshop, if so take a look at some of my video tutorials on You Tube for examples.  You can find the links on my website in my Signature. 

Carole 

Sorry for going off topic here but I had a look at your website last night, Carole, and found the video tutorials to be very informative and easy to understand. 

I loved your Horsehead Nebula image in your level and curves video. I would be interested to know your integration time and what setup you used etc...

Thanks,

Jonny

Edited June 17, 2021 by Jonny_H

[carastro]

Thanks for your comments Jonny H think we had better speak via private message so as not to hijack this thread.

Carole 

[powerlord]

Any chance posting in new thread? I'd find that interesting and I'm sure others too 

[carastro]

You can find my video tutorials on my website which is in my signature.

Carole