191 replies to this topic

[mmalik]

Wouldn't it be helpful and more specific to post a chart with common DSLRs and the options available to each of the cameras, with a recommendation for each?

 

Good idea; I'll see if I can compile a list with everyone's help; it is going to be bit exhausting. Regards

Edited by mmalik, 29 August 2016 - 09:21 PM.

[Ketut]

In post #35... above since #4 & #5 are full-spectrum mods and if one were using a NB filter (H-alpha, etc.) then there really is no need to block UV/IR since NB is going to block UV/IR anyway.

 

 

So your understanding is correct and that's what I tried to say as well. My sentence is malformed a bit, sorry; I should have said 'NO' external UV/IR block required if using a NB filter in option #4 & #5. Hope this clarifies? Regards

 

 

Note: For accuracy, this is regarding options listed in post #35 above since options listed in post #1 are numbered bit differently

Ahhhh got it...thank you so much on this 

[mmalik]

Although I use high precision Vernier caliper... for sensor positioning, a good alternative for the record below...
 

For the sensor attachment screws, I mark them with a fine point sharpie so that the line faces the small black plastic post next to the screw, and then I tighten down the screw till it is hand tight and mark the metal support with the sharpie where the line on the screw is now pointing. I then back the screw off to its original location (the black plastic post) and do the next screw. Then rinse and repeat on the next and so on.

When you reassemble and install the sensor simply tighten all (typically 3) screws down to hand tight and then back each one off until pointed at the black plastic post. This will ensure you place the sensor back in it will be *exactly* where it was installed at the factor by Canon, which is very important to keep the focal plane aligned with the camera mount, etc.

If the screw turns more than one turn where you pass the black plastic post and keep going, just note how many times you do that so you know how many times to pass it during reassembly...

Edited by mmalik, 13 October 2016 - 01:17 AM.

[WillCarney]

What would be the result of a full spectrum be for astrophotography? No external filters, etc. Subjects would be DSO's, no planetary.

Is it advisable or are filters of some sort at least are required?

I have a full spectrum D40x.  I also have a normal D5100.

I like the full spectrum.  I can use it with a SCT, refractor, normal Nikon lens.  I have several IR-UV cut filters already.

Having the full spectrum give me more sensitivity in the red range and more choices.

William

[AnakChan]

Wow! An old post! Thanks for your reply William. Back then I think at that time I was deciding on whether to have the CentralDS A7S mod with clear glass or Hoya UV/IR. I opted for the UV/IR in the end.

[WillCarney]

I did some research for some time.  Then I purchased a D40x full spectrum to go with my un-modded D5100.  I like the full spectrum for those reasons.  I use refractors, SCT's, and camera lenses.  I already have two or three different IR-UV cut filters.  One fits on the camera lenses while one fits on the t-mount.  The full spectrum is also more red sensitive in the hydrogen and far red than using a filter in the camera.  I've got some good images in the far red.  I also use the filters with my Orion Supershot B&W camera.

 

I plan to purchase two cameras as soon as I can afford them.  Both D5300 with getting one modded full spectrum.

 

How did your option turn out?

 

William

[Obi-Wan Kenewbie]

Greetings! I am thinking to buy the new astronomik clip in filter 12nm Ha to use it under my light polluted sky and then combine with  RGB data from dark sky. My a7s is not full spectrum only LPF-2 removed. Is that a possible plan or do you think it will be wasted money?

 

thank you

 

http://www.astronomi...lpha-7r-7s.html

Edited by Obi-Wan Kenewbie, 22 February 2017 - 01:39 AM.

[mmalik]

Obi, for typical scope/focuser based imaging, I like following RGB setup with D1 unless you have lens or other requirements? Have you tried D1 with your sky conditions?

 

 

Given the inherent RGB nature of MILCs/DLSRs I would advise against the mono imaging. RGB cooling... my be a better investment than going the narrowband route. Regards

 

 

Note: D1 along with 'Cooler @ the Base' a7S image sample here... taken from a suburban location

 

 

 

Edited by mmalik, 22 February 2017 - 03:55 AM.

[Obi-Wan Kenewbie]

Greetings mmalik! Cooling is scheduled but my rig is only lenses till now in a very red zone.

[mmalik]

D1 comes in various configuration for use with a lens or inside a7S; give that a try if you haven't already. Why go the narrowband when you an capture close to it with RGB sensitivity of a7S. Regards

Edited by mmalik, 22 February 2017 - 02:59 PM.

[AstroOlly]

The mod is also Also known as "hot mirror removal" ....

Olly

[mmalik]

LPF-2 Replacement Options (Baader)..........Old Name..........New Name

 

APS-C...........................................................FBCF-400D..........BCF1
Full Frame.....................................................FBCF-5DII...........BCF2

 

 

Note: These filters will fit most Canons, Nikons, Sonys, etc.

Edited by mmalik, 22 March 2017 - 10:50 PM.

[jayta98]

Hi Mike, thank you for taking the time for explaining the DSLR modifications. I'm looking to modify my Canon T5. I understand that if I want to keep the auto focus via viewfinder I would need to put the sensor back in the exact location. My plan would be to just remove the LP2 filter and make the camera AP dedicated. I believe if this the case I don't have to be that critical with the sensor distance. Is that correct?

 

Also the T5 will be used with a William Optics 71mm ED refractor, from what I read this this could cause star bloating. Will a clip on filter prevent the star bloating? If not what would I need to prevent it? Thanks.

[mmalik]

With 'Removed LPF-2' mod I'll recommend supplementing with an IDAS D1 for most astro work. If you need to preserve autofocus with 'Removed LPF-2' mod, you'll need to move sensor forward a bit. For astro work you don't need to worry about autofocus and you can leave the sensor in its original spot. Hope this helps. Regards

Edited by mmalik, 25 March 2017 - 02:05 PM.

[jayta98]

With 'Removed LPF-2' mod I'll recommend supplementing with an IDAS D1 for most astro work. If you need to preserve autofocus with 'Removed LPF-2' mod, you'll need to move sensor forward a bit. For astro work you don't need to worry about autofocus and you can leave the sensor in its original spot. Hope this helps. Regards

Would Astronomik CLS Canon EOS Clip Filter work also? Is it better to keep the filter as closest to the sensor(clip on) vs at the end on the 2 inch T adapter(2 inch screw on)?

[mmalik]

I have my reservations about CLS-CCD in light of Jerry's comments here.... As far clip vs. T-adapter placement goes, that should 'not' make any difference [except for some minor vignetting ramifications in clips]. Regards

Edited by mmalik, 25 March 2017 - 08:41 PM.

[mmalik]

IR Blocker 'ON' the Sensor, with h-alpha transmission?

 

 

Note: These are rectangular filters that go 'ON' the sensor [my question is NOT about external, or round IR filters]

 

 

In case of 'Removed LPF-2' mod, the remaining 'LPF-1' becomes the de facto IR blocker with h-alpha transmission.

 

 

In case of Baader mod, Baader becomes IR blocker with h-alpha transmission (image below)

 

 

I am wondering what other IR blocker with h-alpha transmission options are out there for 'ON' the sensor use; I would like details and links to such filters. I am not looking for proprietary, vendor specific filters that are not available for general sale. Regards

Attached Thumbnails

• 

Edited by mmalik, 17 May 2017 - 03:43 PM.

[jag32]

With changing times, here is the revised list:
 

 

Mod Choices:

 

 

1. LPF-2 removed and replaced with a modified filter [stock LPF-1 AS-IS]

2. LPF-2 removed and NOT replaced [stock LPF-1 AS-IS] (My recommendation...)

3. LPF-2 removed and replaced with clear glass [stock LPF-1 AS-IS]
 
Note: This is 'old' thinner clear glass and is getting somewhat obsolete in favor of the 'new' #5 below


4. Both, LPF-2 and LPF-1 removed (full spectrum) [external UV/IR block required]
 
5. Both, LPF-2 and LPF-1 removed (full spectrum) and replaced with clear glass [external UV/IR block required]
 
Note: This is 'new' thicker clear glass than #3; its optical thickness is equivalent to combined two removed filters


6. LPF-2 removed and replaced with a modified filter & stock LPF-1 removed [this is quite rare and unorthodoxy]
 

 

 

Note: All options, except #4 and #5, 'may not' require external UV/IR block; additional UV/IR block can be added for refractive optics (to prevent star bloating). Light pollution suppression is something that can be used with any mod type


Note: Narrowband (NB) filter can be used with any mod type; 'NO' #4 or #5 external UV/IR block required if using a NB filter

 

 

IMPORTANT: Not all sensor designs allow for all mod choices. Sometimes for example LPF-1 and LPF-2 may be bonded together; in such cases full-spectrum mod may be the only option!

 

 

To conclude, remember this...

"Essene of any astro mod is to get rid of stock LPF-2"

So I understand this correctly, your recommendation is full spectrum mod with NO clear glass installed?

 

I am very confused on whether the clear glass is or is not recommend. Thanks n

Edited by jag32, 01 November 2017 - 09:07 PM.

[mmalik]

My recommendation is 'Removed LPF-2' mod (not full-spectrum). Note that not all sensor designs are amenable to 'Removed LPF-2' mod (e.g., where LPFs may be bonded together).

 

 

Clear glass (whenever used) is to preserve autofocus (as stock filter/s are removed), something not needed for astro work. Regards

Edited by mmalik, 01 November 2017 - 09:35 PM.

[jag32]

My recommendation is 'Removed LPF-2' mod (not full-spectrum). Note that not all sensor designs are amenable to 'Removed LPF-2' mod (e.g., where LPFs may be bonded together).

 

 

Clear glass (whenever used) is to preserve autofocus (as stock filter/s are removed), something not needed for astro work. Regards

Thank you.  Do you know if the "removed LPF-2" mod is possible on the Pentax K1 or only full spectrum?  

 

Thanks again

[mmalik]

Full-spectrum and Baader are some of the mod options in K1. Regards
 
 

Fight moire with the Pentax K1's Anti-Aliasing Filter Simulator...

Also retained from Ricoh's APS-C DSLR lineup is the Pentax K-1's Anti-Aliasing Filter Simulator function. It's no longer completely unique, as Sony has achieved the same thing in hardware in some of its latest cameras, but it's still pretty special. There's no resolution-sapping optical low-pass filter over the image sensor -- something most interchangeable-lens cameras also lack these days -- but unlike the competition, the K-1 can emulate it by moving the image sensor just slightly during the exposure. This can slightly soften the image as the low-pass filter would have done, and in the process help to prevent moiré and false-color effects.

Edited by mmalik, 01 November 2017 - 10:01 PM.

[photonhunter7]

It looks like my initial question generated a lot of response and information.  Wow- Now I will have to study all the thoughts and proceed from there.  Thank you very very much.

Burton

[Astrohoven]

Thought I'll outline major DSLR modification types for easy understanding, and knowing what choices one has available when modifying a DSLR.

 

 

IMPORTANT: First and foremost, DSLR filters are referred to with many names, and all mean different things to different people. Here is a compilation of names these filters may be referred to. BUT I would advise that you use standard naming convention like LPF-1 or LPF-2 instead...

 

 

LPF-1

• Front Filter
• Dust removal filter
• Piezo element filter
• IR/UV block filter
• H-alpha pass filter
• Larger filter
• Pinkish looking filter
• Anti-alias filter (1)

 

LPF-2

• Rear Filter
• Color limiting filter
• White Balance filter
• IR/UV block filter
• H-alpha block filter
• Smaller filter
• Bluish looking filter
• Anti-alias filter (2)

 

 

Mod Choices:

 

 

1. LPF-2 removed and replaced with a modified filter [stock LPF-1 AS-IS]

 

2. LPF-2 removed and NOT replaced [stock LPF-1 AS-IS] (My recommendation...)

 

3. LPF-2 removed and replaced with clear glass [stock LPF-1 AS-IS]

 

4. Both, LPF-2 and LPF-1 removed (full spectrum) [external UV/IR block required]

 

5. LPF-2 removed and replaced with a modified filter & stock LPF-1 removed

 

 

 

Note: All options, except #4, 'may not' require external UV/IR block; additional UV/IR block can be added for refractive optics (to prevent star bloating). Light pollution suppression is something that can be used with any mod type

 

 

Note: Narrowband (NB) filter can be used with any mod type; 'NO' #4 external UV/IR block required if using a NB filter

 

 

 

To conclude, remember this...

 

"Essene of any astro mod is to get rid of stock LPF-2"

 

 

 

Is the LPF1 filter enough to block IR and not cause star bloating? I'm using a newtonian with a coma corrector so I'm a bit worried about star bloating if I decide to not go for a UV/IR filter.

[mmalik]

You would need to supplement LPF-1 with LPS... to achieve the needed results and that's pretty much the standard for AP in a nutshell that people will write volumes to explain. Regards

[maxmir]

I just finished did my own 6D modification. I went with a Baader replacement.
I think this the most cost effective and flexible solution.

Best for Astro and daytime autofocus will still work.

99% imagers will eventually use a lens somewhere in their optical system.
Then you end buying a clip on. It would be nice to replace LPF1 and LPF2 with single glass that has enough IR cut.

I did not see that option available

Max