Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Normal vs. Astro Modified - Thoughts on this comparison.

  • Please log in to reply
28 replies to this topic

#1 ssa2294

ssa2294

    Sputnik

  • -----
  • topic starter
  • Posts: 37
  • Joined: 29 Oct 2018

Posted 17 September 2019 - 09:54 PM

So I have decided to get a 2nd DSLR camera and was considering having the 2nd one astro modified. I began reading through threads here, and what info I could find elsewhere. A lot of confusion, a lot of opinions for and against. However I was kind of paying attention to reviews users here had about different places to do it, I figure if I ever went ahead I would use Life Pixel. Now my question is this, on Spencercamera's website in the Astro vs Normal comparison are 2 images. I would like to ask, are these accurate of what one would expect with a full spectrum modification done? I seen a lot of opinion on Spencers, but nobody commented on the images displayed. Looking at that comparison it seemed almost a no brainer to do a full spectrum mod. However, I think there is something not being detailed. Honestly, if this comparison was accurate, I would expect almost everyone to be doing it, almost no argument against modification. But most modification advice I have read to date has been to just do HA. 

 

Can some please share some insight into all this? Do you believe there truly was no post processing done? Is this truly accurate representation? 



#2 Jim Waters

Jim Waters

    Gemini

  • *****
  • Posts: 3000
  • Joined: 21 Oct 2007
  • Loc: Phoenix, AZ USA

Posted 17 September 2019 - 10:28 PM

If you get a full spectrum mod you will have to use an IR/UV filter.  If you are considering getting a full frame camera many if not all clip-in filters cause vignetting (if you are using a camera lens).

 

I used LifePixel for my Ha modifications - Canon T3i and 6D.

 

What's the camera?


Edited by Jim Waters, 17 September 2019 - 10:41 PM.


#3 t_image

t_image

    Gemini

  • -----
  • Posts: 3217
  • Joined: 22 Jul 2015

Posted 17 September 2019 - 10:39 PM

So I have decided to get a 2nd DSLR camera and was considering having the 2nd one astro modified. I began reading through threads here, and what info I could find elsewhere. A lot of confusion, a lot of opinions for and against. However I was kind of paying attention to reviews users here had about different places to do it, I figure if I ever went ahead I would use Life Pixel. Now my question is this, on Spencercamera's website in the Astro vs Normal comparison are 2 images. I would like to ask, are these accurate of what one would expect with a full spectrum modification done? I seen a lot of opinion on Spencers, but nobody commented on the images displayed. Looking at that comparison it seemed almost a no brainer to do a full spectrum mod. However, I think there is something not being detailed. Honestly, if this comparison was accurate, I would expect almost everyone to be doing it, almost no argument against modification. But most modification advice I have read to date has been to just do HA. 

 

Can some please share some insight into all this? Do you believe there truly was no post processing done? Is this truly accurate representation? 

It doesn't matter about single image comparison, although it is nice they show UNPROCESSED single images.

 

The issue is AP is about taking lots of images of different objects in the sky.

Good advice is based on thorough experience with many objects and subjects people may desire to image in the night sky.

The decision should be requirements based,

as they (Astro HA sensitive IR block filter) v (Full Spectrum)

are different tools for different uses.

Full spectrum won't give you much star-bloat in IR rich stars if you are using a reflector with minimal glass optics,

but with lenses or a refractor stars rich in IR with bloat and look unfocused due to Chromatic aberration because different parts of the spectrum focus at different points.

NB the point is moot, there is no CA.

A HA sensitive IR block filter mod will give you the typical astro benefit without worrying about star bloat in refractor optics.

Here's some comparison images with different filters in a 'full spectrum' mod which even the term 'full spectrum' is wrong because atmosphere and glass and the color filter array on the sensor block much UV..........

https://www.cloudyni...e/#entry7097437


  • wrnchhead likes this

#4 wrnchhead

wrnchhead

    Apollo

  • *****
  • Posts: 1017
  • Joined: 28 Aug 2017
  • Loc: NE Kansas

Posted 17 September 2019 - 11:12 PM

Wow that's a point of view I hadn't heard t_image. I modified my original DSLR (an ancient 1000D) and was wowed with the results. I just removed everything but the sensor itself. But now I realize it may have been because of my target. I got a newer 1300D and was considering modding it before ever even trying it out but maybe I should look deeper into a subject I considered an open and shut case. 


  • t_image likes this

#5 Ed Wiley

Ed Wiley

    Surveyor 1

  • *****
  • Posts: 1982
  • Joined: 18 May 2005
  • Loc: Texas, USA

Posted 17 September 2019 - 11:33 PM

I have a full spectrum and use a clip-on filter that samples the spectrum similar to a Ha-modified camera. But, I can take off the filter, slap on a IR filter (not IR-cut) and take IR pictures if I like. There are even filters that mimic unmodified cameras. So full spectrum is nimble if you are willing to invest in extra filters.

 

IMO, "accurate representation" is an elusive goal. I think impressionism is a better goal.

 

Ed


  • t_image and wrnchhead like this

#6 Jim Waters

Jim Waters

    Gemini

  • *****
  • Posts: 3000
  • Joined: 21 Oct 2007
  • Loc: Phoenix, AZ USA

Posted 18 September 2019 - 12:11 AM

The "sensor" spectrum below is from a Canon EOS.  This is a typical spectrum for a Full Spectrum mod.  If you do not use an UV/IR filter you are going to get bleeding cross-over from blue and green which will give the deep red and deep blue images false colors.

 

Canon DSLR FS Mod

Edited by Jim Waters, 18 September 2019 - 01:46 AM.

  • elmiko and t_image like this

#7 ssa2294

ssa2294

    Sputnik

  • -----
  • topic starter
  • Posts: 37
  • Joined: 29 Oct 2018

Posted 18 September 2019 - 08:00 AM

If you get a full spectrum mod you will have to use an IR/UV filter.  If you are considering getting a full frame camera many if not all clip-in filters cause vignetting (if you are using a camera lens).

 

I used LifePixel for my Ha modifications - Canon T3i and 6D.

 

What's the camera?

I have yet to decide my path. I have a Nikon d5300 and considered another used d5300 used to have modified. Also a thought to get a Canon SL2 or T6i, then I would have decide whether to have the Nikon or Canon modified. Only thing I am sure of is that I will use LifePixel. 

 

It was the comparison found here that made me question the accuracy or whether this was a truly realistic representation of Full Spectrum mod without processing. The image comparison just seemed deceptive. I unfortunately have not truly found a lot of good accurate and reliable comparisons to judge for myself.



#8 Tom K

Tom K

    Viking 1

  • *****
  • Posts: 623
  • Joined: 19 Jan 2010
  • Loc: Escondido, CA

Posted 18 September 2019 - 08:26 AM

I modded my old T1i myself and use a CLS-CCD clip in filter (I have a sodium street lamp about 100 feet from my telescope).  The change is pretty dramatic for objects like Horsehead Nebula and less dramatic for galaxies and the like.  If you control the UV issues, there is no reason to lose out on those photons!


  • t_image, wrnchhead and OldManSky like this

#9 t_image

t_image

    Gemini

  • -----
  • Posts: 3217
  • Joined: 22 Jul 2015

Posted 18 September 2019 - 06:20 PM

I have yet to decide my path. I have a Nikon d5300 and considered another used d5300 used to have modified. Also a thought to get a Canon SL2 or T6i, then I would have decide whether to have the Nikon or Canon modified. Only thing I am sure of is that I will use LifePixel. 

 

It was the comparison found here that made me question the accuracy or whether this was a truly realistic representation of Full Spectrum mod without processing. The image comparison just seemed deceptive. I unfortunately have not truly found a lot of good accurate and reliable comparisons to judge for myself.

You can use the advanced search of CN to find out about the reputation of Spencer as a vendor,

but it is strange you are so skeptical about the images they posted without being familiar with the gear yourself. A hotmirror (IR block filter) removal does significantly increase the sensitivity and allows for quicker pickup with IR light/sources.

That explains the foreground and MW looking brighter.....

Here's a video camera IDAS modified:

https://www.youtube....h?v=UJdpd0uy_tk

 

I was modding video cameras for low light applications for the boost in low light and ability to use IR illuminators for wildlife long before I got into astro with a still camera.

 

Most people don't own a mod and unmodded version and rarely do people take images prior to sending them in with the same conditions to make such example.

 

Here's a video where someone put a comparison (factory v full spectrum mod) through its paces in low light, non-astro. I own an a7s both modded (clear glass) and unmodded and can verify it is consistent with the difference.

https://www.youtube....h?v=c30u4Q1Wu64

Of course the red color cast is because the person didn't bother to do any color correction on the full spectrum content that could have more properly restored the colors with a proper WB/tint adjust......



#10 wrnchhead

wrnchhead

    Apollo

  • *****
  • Posts: 1017
  • Joined: 28 Aug 2017
  • Loc: NE Kansas

Posted 18 September 2019 - 06:40 PM

So T, I did notice in the processing, that my image (I am horrified to share much yet, still so new lol) had the normal blue and green peaks in the histo in their "normal" places, and the red peak was further up the graph. So in PS I brought the red down to where the blue and green were, is this what you mean by the WB/tint adjust? 

 

My resultant image did have a lot of red, but it was my belief that it was the hydrogen I was missing before, now revealed. 

 

(Not asking you to hold my hand to understand the whole of these concepts, just confirming what I understand to be going on) 



#11 17.5Dob

17.5Dob

    Fly Me to the Moon

  • ****-
  • Posts: 5240
  • Joined: 21 Mar 2013
  • Loc: Colorado,USA

Posted 18 September 2019 - 07:32 PM

This is a comparison between my stock D7100 and a modded D5300, all other variables being equal. Location, exposure , f ratio, both processed the same.

48200885547_6e2a0cd98b_h.jpg

 


  • tonyt, Tom K, t_image and 4 others like this

#12 17.5Dob

17.5Dob

    Fly Me to the Moon

  • ****-
  • Posts: 5240
  • Joined: 21 Mar 2013
  • Loc: Colorado,USA

Posted 18 September 2019 - 07:33 PM

Another side by side comparison stock on top, modded below.

48318979662_5a0415d102_o.jpg


  • Traveler, tonyt, Tom K and 5 others like this

#13 t_image

t_image

    Gemini

  • -----
  • Posts: 3217
  • Joined: 22 Jul 2015

Posted 18 September 2019 - 09:28 PM

So T, I did notice in the processing, that my image (I am horrified to share much yet, still so new lol) had the normal blue and green peaks in the histo in their "normal" places, and the red peak was further up the graph. So in PS I brought the red down to where the blue and green were, is this what you mean by the WB/tint adjust? 

 

My resultant image did have a lot of red, but it was my belief that it was the hydrogen I was missing before, now revealed. 

 

(Not asking you to hold my hand to understand the whole of these concepts, just confirming what I understand to be going on) 

Good question. Of course I was referring to the terrestrial video where sound color principles apply and there is no argument..

So it is complicated as Jim's post alludes to, that the IR invades not only only the red but also blue and green channels,

---------and daytime IR photographers take advantage of this with IR pass filters of different cut-offs to exploit the "false colors."

 

Not only does IR light invade all three channels (how it does (ie not in a balanced way) ---depends on the particular dye and tech of the particular model and manufacturer (all color filter arrays are not the same),

but the H-alpha and other visible long-wave red light also makes the red channel much more pronounced....

(hence the color cast in the video).....

The objective way to try to get back to a color norm with WB/tint is by referring to a known referent point and then "balancing the channels in reference to that point....

 

Often in photography people over-simplify white-balance as just concerning "color temperature" of the light source lighting a scene. If it were than simple.

However, many light sources not only have a color temperature drift (blue/amber),

but they also have a tint (magenta/green). There are situations where color correction of the overall image cannot completely remove a color cast,

so one has to do secondary color correction (selective color changes)......

 

This recent thread explores clarification of the ways this can be done,

see the link (astropix) where Jerry gets into this.

https://www.cloudyni...alance-question

 

PixInsight software also has some fun methods:

[and you can see from exploring the two links that people have different opinions about color in AP]

https://pixinsight.c.../PCC/index.html

https://pixinsight.c...ml#__contents__

 

***concerning the histogram:

note the histogram only shows a peak because of the numerical number of PIXELS, it tells you nothing about particulars of the image.

That is why video is all about the waveform(parade) and vectorscope tools :

https://www.cloudyni...aphy/?p=9418470

 

However photography and astrophoto tools don't utilize these so everyone thinks the histogram is great.frown.gif

 

https://www.dpreview...than-histograms



#14 wrnchhead

wrnchhead

    Apollo

  • *****
  • Posts: 1017
  • Joined: 28 Aug 2017
  • Loc: NE Kansas

Posted 18 September 2019 - 09:57 PM

Awesome, I have some reading to do! Thank you.

17.5, great shots!

#15 Alen K

Alen K

    Apollo

  • -----
  • Posts: 1079
  • Joined: 25 Nov 2009

Posted 19 September 2019 - 07:49 AM

Another side by side comparison stock on top, modded below.

48318979662_5a0415d102_o.jpg

Not to derail the thread but one thing I notice about the second image is what looks like green "fog" in the center of the frame. This is not the first time I have seen this in exactly the same place in images of this region. Because I have seen it before I am almost inclined to believe it is real (despite the fact that it is green) but could it be some sort of flat-fielding artifact? 


Edited by Alen K, 19 September 2019 - 07:50 AM.


#16 WolfBiederman

WolfBiederman

    Sputnik

  • -----
  • Posts: 44
  • Joined: 11 Feb 2019
  • Loc: Statesville, NC

Posted 05 October 2019 - 05:18 PM

This is a comparison between my stock D7100 and a modded D5300, all other variables being equal. Location, exposure , f ratio, both processed the same.

48200885547_6e2a0cd98b_h.jpg

 

 

 

Another side by side comparison stock on top, modded below.

48318979662_5a0415d102_o.jpg

What optics were you using for these shot and were you using any filters for either? Love seeing how big a difference a normal vs FS mod is.

 

I'm considering getting my D600 FS modded but wasn't sure if I should go HA instead.


Edited by WolfBiederman, 05 October 2019 - 05:19 PM.


#17 17.5Dob

17.5Dob

    Fly Me to the Moon

  • ****-
  • Posts: 5240
  • Joined: 21 Mar 2013
  • Loc: Colorado,USA

Posted 05 October 2019 - 07:11 PM

What optics were you using for these shot and were you using any filters for either? Love seeing how big a difference a normal vs FS mod is.

 

I'm considering getting my D600 FS modded but wasn't sure if I should go HA instead.

The modded cam used a Samyang 85mm lens stopped down to f5. The only filter was the UV/IR cut.

For 99% of people, an Ha mod is plenty.



#18 Teddythefinger

Teddythefinger

    Vostok 1

  • -----
  • Posts: 150
  • Joined: 04 Sep 2018

Posted 05 October 2019 - 07:14 PM

This is a good topic because I don't understand this too much, bit I do have an old xti I want to try to modify! So....taking off both lp glasses makes it full spectrum and only taking off the 2nd lp glass makes it ha sensitive?

Sent from my moto g(6) using Tapatalk
  • wrnchhead likes this

#19 WolfBiederman

WolfBiederman

    Sputnik

  • -----
  • Posts: 44
  • Joined: 11 Feb 2019
  • Loc: Statesville, NC

Posted 05 October 2019 - 08:31 PM

This is a good topic because I don't understand this too much, bit I do have an old xti I want to try to modify! So....taking off both lp glasses makes it full spectrum and only taking off the 2nd lp glass makes it ha sensitive?

Sent from my moto g(6) using Tapatalk

Someone else would know better but I believe it's camera specific. I believe some have multiple filters some have one. Pretty sure that's what I read. Not 100% on that though.



#20 Im2bent

Im2bent

    Vostok 1

  • -----
  • Posts: 140
  • Joined: 23 Aug 2018

Posted 17 October 2019 - 08:34 PM

One thing I don't see in any of these 5300 threads is which Ha only mod because lifepixel has three choices if I am reading this right. Standard at 720nm enhanced at 665nm and super color at 590nm. Thoughts?



#21 nofxrx

nofxrx

    Vendor (HyperCams & Mods)

  • *****
  • Vendors
  • Posts: 5518
  • Joined: 12 Jul 2005
  • Loc: Melbourne, Florida

Posted 17 October 2019 - 09:05 PM

This is a good topic because I don't understand this too much, bit I do have an old xti I want to try to modify! So....taking off both lp glasses makes it full spectrum and only taking off the 2nd lp glass makes it ha sensitive?

Sent from my moto g(6) using Tapatalk

That is correct. The second filter has a blue green tint to it and is the "bad for astro" filler. The front filter is not a complete IR block (as a Baader/etc) but is usually more than enough for most people/ setups. If you still get some IR star bloat you may need to add an IR block somewhere/anywhere...

 

Cheers


  • Teddythefinger likes this

#22 t_image

t_image

    Gemini

  • -----
  • Posts: 3217
  • Joined: 22 Jul 2015

Posted 17 October 2019 - 10:50 PM

One thing I don't see in any of these 5300 threads is which Ha only mod because lifepixel has three choices if I am reading this right. Standard at 720nm enhanced at 665nm and super color at 590nm. Thoughts?

You need to read lifepixel in the context that they do much more mods for a larger population of customers, in doing daytime INFRARED PHOTOGRAPHY.

That may be why you don't see an astrophoto anywhere on the homepage of their site and "infrared conversion" is pasted all over and it takes quite an effort to even find the section that concerns astrophotography.

 

So maybe since you think you've read enough to know there are so many threads, go back through the '5300 threads' and read more carefully how there is a drastic distinction between daytime infrared photography conversion and a conversion useful for astrophotography.

Super color 590nm for example will be crap for astrophotography. Take a look at the example images? Are those nebula and astrophotos? No. Did you wonder why?

 

Careful observation is a skill that is important in this hobby.



#23 Im2bent

Im2bent

    Vostok 1

  • -----
  • Posts: 140
  • Joined: 23 Aug 2018

Posted 17 October 2019 - 11:07 PM

You need to read lifepixel in the context that they do much more mods for a larger population of customers, in doing daytime INFRARED PHOTOGRAPHY.

That may be why you don't see an astrophoto anywhere on the homepage of their site and "infrared conversion" is pasted all over and it takes quite an effort to even find the section that concerns astrophotography.

 

So maybe since you think you've read enough to know there are so many threads, go back through the '5300 threads' and read more carefully how there is a drastic distinction between daytime infrared photography conversion and a conversion useful for astrophotography.

Super color 590nm for example will be crap for astrophotography. Take a look at the example images? Are those nebula and astrophotos? No. Did you wonder why?

 

Careful observation is a skill that is important in this hobby.

So you are recommending the 720nm filter thanks.



#24 t_image

t_image

    Gemini

  • -----
  • Posts: 3217
  • Joined: 22 Jul 2015

Posted 17 October 2019 - 11:30 PM

So you are recommending the 720nm filter thanks.

?????sarcasm

 

If by 720nm you mean lifepixel standard infrared filter,

then you not appreciate as a permanent mod if you want to do AP.

That's why all the threads recommend h-alpha astro OR full spectrum, not any of the 6 IR pass filters (including the 720) that are for daytime IR photography only.

And UV requires special lens and is for forensics or daytime as well.

 

 "With our digital infrared camera conversion service you have the choice of 6 IR filters. Along with a UV-Vis-IR full spectrum filter, H-alpha Astro filter & UV ultraviolet filter."

https://www.lifepixe...filters-choices

 

You can do full spectrum and use an IR pass filter for special circumstances, but a 720m IR filter (which is not H-alpha Astro and is not full spectrum) mod it's not a good permanent choice since you can't ever again capture any visible colors with it.

https://www.cloudyni...t/#entry6966745

https://www.cloudyni...t/#entry6908254

https://www.cloudyni...shot-of-rainbow

https://www.cloudyni...r/#entry7057595

https://www.cloudyni...g/#entry7046668

https://www.cloudyni...o/#entry7504690

https://www.cloudyni...d/#entry6880695



#25 Teddythefinger

Teddythefinger

    Vostok 1

  • -----
  • Posts: 150
  • Joined: 04 Sep 2018

Posted Yesterday, 04:09 AM

That is correct. The second filter has a blue green tint to it and is the "bad for astro" filler. The front filter is not a complete IR block (as a Baader/etc) but is usually more than enough for most people/ setups. If you still get some IR star bloat you may need to add an IR block somewhere/anywhere...

Cheers

Thank you!

Sent from my moto g(6) using Tapatalk


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics