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UltravioletPhotography

Greetings from Portugal!


ACRosalino

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Hello, everyone

 

I am an amateur astrophotographer from Portugal, born in the year of Apollo 8, who has been imaging deep-sky objects with specialized (mono & cooled) CCD cameras, using a variety of telescopes, both with "visual" filters (Luminance+RGB) and also "narrow band" filters (SII, Ha, OIII emissions).

 

While imaging deep-sky objects normally excludes IR and UV wavelengths, recently I have been intrigued by what can be achieved photographing more earthly subjects in this "invisible" part of the spectra, using consumer DSLR and mirrorless cameras.

 

Looking forward to learn from the vast experience shared in this "UV Photography" forum... and hoping to be able to start putting together a functional UV/IR imaging setup, soon!

 

Thank you all and

best wishes for the New Year of 2019 :-)

Antonio Rosalino

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Thank you, Terry!

My UV/IR journey is just at the beginning, I am reading as much as I can, over here, so that I can start looking for the adequate equipment... so far, I believe I have secured one of the recommended "vintage" lenses and also a flash, to be modified - small, baby steps :-)

Antonio Rosalino

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Thank you, Terry!

My UV/IR journey is just at the beginning, I am reading as much as I can, over here, so that I can start looking for the adequate equipment... so far, I believe I have secured one of the recommended "vintage" lenses and also a flash, to be modified - baby steps :-)

Antonio Rosalino

 

Well this forum is filled with info and very friendly and helpful individuals.

 

I just got a book by Adrian Davies called Digital Ultraviolet and Infrared Photography and although I haven't finished reading it yet, its filled with tons of info.

Filters (including flash filters) you get from Cadmium.

 

It was recommended to me to get a Nikkor 80 or 105mm enlarger lens, which I did, as well as the attachments etc, which Dabateman was kind enough to help me with.

 

It is, however, daunting, when reading through some of the posts here. The scientific lingo gets the better of me.

 

I am really looking forward to learning more about how and with what you captured those lovely images. Perhaps a photo of your gear?

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Thanks, Cadmium: well, there is an entire Universe out there, just waiting to be discovered - all we have to do it point our telescopes or camera lenses to the skies above and capture its wonders :-)

 

Terry, deep sky imaging of galaxies, nebular, star clusters, etc. requires a few specialized items:

 

* a telescope or camera lens: I have used various types of scopes and lenses over the years, only to realize that there is no substitute for great optics.

"Good enough" glass for terrestrial photography has limited use for astronomy: imaging pinpoint stars against a black velvet background is the ultimate optics challenge.

I use a couple of 5" and 6" triplet apochromatic refractors, corrected across the entire visible range and a 14" Schmidt-Cassegrain telescope, for the smaller objects or ocasional planetary imaging. None of those scopes would do well at UV wavelengths, because of the lens coatings; besides, the atmosphere filters most UV emitted by those objects - bright Venus being a notable exception, that's why planetary imagers use Baader and Astrodon UV filters to capture some details of its clouds.

 

* an equatorial mount, with the capacity to carry the telescope+imaging gear and the tracking precision required to keep the target objects 100% stationary, while you are exposing - usually for 5, 10 or 15 minutes at a time.

 

* a DSLR/mirrorless camera or (better) a specialized CCD/CMOS camera: I use the later, with a 16MP monochrome sensor, which can be cooled down to -25ºC or lower, in order to reduce "noise". Deep sky images are normally several minutes long, the target objects are very faint and we want to minimize noise x signal.

Spectral response of this specific CCD goes into the UV/IR range, maybe one day I will be able to test it on terrestrial objects, with an appropriate camera lens...

 

* motorized focuser - we want pinpoint stars and software based focusing works better than the naked eye;

* motorized filter wheel - mine is loaded with 4 "visual" filters (for Luminance+Red+Green+Blue) and 3 narrow band filters (for Sulphur II, Hydrogen-alpha and Oxygen III emission lines) - all from Baader, Germany.

* astro-imaging software, to enable control and automation of the above equipment and to perform the calibration and post-processing of the images.

 

Deep-Sky Imaging being the art and technique of capturing on camera the incredibly distant and faint objects, sometimes I think of it as a "time machine"... for I am capturing elusive photons, which have often travelled through space for millions of years, until they were finally captured by a small piece of silicon inside my CCD camera, finally allowing for them to be seen - and how can that be any short of a true modern day's miracle?

 

Regards,

Antonio Rosalino

 

PS: below is an image of the Triangulum Galaxy (Messier object #33) - practically our neighbor, captured on camera as it was some 3 million years ago!

Also, the Eagle Nebula (M16) and the Horsehead nebula (in constellation Orion), showpieces located within our own backyard / milky way :-)

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Excellent images.

Is your cooled 16Mpixels camera the Zwo 1600MM pro?

I would love to test that camera out. If so you may have the best UV capable camera out there, at least for macro work.

 

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Hello Antonio - and Welcome to UVP! My apologies for being a bit late in greeting you as I've had a few things going on at home.

Your astro images are wonderful! I love those kinds of images so much and wish I could try it someday.

 

I think if you look through our reference section you will find lots of good info for getting started in reflected UV photography.

 

Here are a few links to get you started. And of course we are always happy to answer questions.

 

UV and Your Eyes :: UV Safety Reference

Xenon Strobe and Flash Safety Hints

 

Sticky :: UV Photography: Cams, Mods, Lights, Links

How to make a UV photograph

 

Sticky :: UV-Capable Lenses

 

Sticky :: UV/Vis/IR Filters

How to use filters for UV photography

 

 

The Horsehead Nebula photo is spectacular!!! WOW !!

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Thank you, dabateman: yes, Asi cameras are now popular in entry level astro-imaging, bringing cheaper CMOS technology mainly from Sony and Panasonic to a field which, until very recently, was dominated by the more expensive CCD sensors, mainly from Kodak (now ON Semiconductor).

My astro camera is still from the old school: it has a KAF-16803 CCD sensor, 4096x4096 pixels, 36mm x 36mm, 52mm diagonal.

The debate around which one is better (CCD or CMOS) is always very intense, I believe the CCD still has the edge, but CMOS technology seems to be the future and it is catching up quickly.

 

Hi Andrea and thank you for the welcome words - If you decide to try astro-imaging, someday, I will be happy to help in what I can :-)

I have read quite a lot of the great info available in this forum, especially what relates to the equipment being used for UV photography.

 

So far, I have managed to grab one of the lenses from the "sticky", a beautiful Steinheil München Cassar-S 50mm f/2.8 M42, which seems to be in great condition, given its very respectful age. Next, I will try to find a couple of EL-Nikkors, likely the 80mm and/or the 105mm: I begin to understand now why so many people simply enjoy collecting these very special "vintage" lenses!

 

I have also grabbed a 199A Canon Speedlite, which I plan to modify by removing its front plastic lens. The funny thing is, I had one of these flashes, maybe some 30 years ago, which I used with my very "precious" (at that time) Canon A1 film camera... tempus fugit.

 

On the filter area, the plan is to get a Baader-U (2" version): I already have 7 or 8 Baader astro-filters (50mmx50mm), so I am confident their UV filter provides the same quality and value.

 

Of course, all the above will be rather useless, unless I find myself a suitable camera: in that respect, I am at still a crossroad:

 

* get another astro-camera, like one of the ZWO Asi CMOS mentioned above and use it also for UV/IR photography?

It has the advantages that one can choose mono or color sensor and there is no need to modify it; on the down side, it will require a filter wheel and it is not practical to use such cameras in the field...

 

* get a DSLR or, more likely, a mirrorless camera?

Main advantage is that it is a complete solution, no need to use a laptop to control it and has live view (and maybe an EVF); on the down side, it will have to be converted to full spectrum... and that is an additional risk, especially here in Europe - any recommendations on where to perform this mod?

 

If I do follow the mirrorless route, I will likely get a Canon EOS M (cheaper solution and can use Magic Lantern) or a Canon EOS M5 (more expensive, but more versatile, also good for astro) - I have other Canon gear so I would like to stay the course, here.

 

Now, it sure seems most users here have Nikon cameras and also Sony, Panasonic, Pentax, Olympus... while Canon seems almost like a rare bird!

It would be great to hear from Canon users, here (are there any?) what has been their experience with such modified cameras?

Interestingly enough, Canon is the top choice for those who have modified their cameras for astro-imaging, so it is rather surprising that in UV/IR photography they seem to be so "under represented"...

 

Best regards,

António Rosalino

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Actually, Jonathan also known as JMC here uses Canon cameras.

He has many posting using full spectrum conversion camera and a monochrome converted body. He also has an odd 50:50 body.

You could PM him if you have specific questions.

 

Too bad you don't own the 1600mm. I would have loved to see some more images out of it.

But still test your current monochrome. It may work well.

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It would be great to hear from Canon users, here (are there any?) what has been their experience with such modified cameras?

 

Hi and welcome António.

 

Your astro images are really fantastic!

 

I am one of the Canon users here and are very satisfied with the results from my camera. Beside me and Jonathan (JMC), I think there are a few more here.

 

I mainly do close-ups on flowers and like to explore different types of filtration.

My camera is a rather old EOS 60D that I modified myself, two years ago, by replacing the internal filter and dust-shaker with a dedicated window from astronomik.de.

I like the articulated LCD display on that camera very much. It is very nice when composing close-ups in some camera-positions.

 

I have plans to convert an EOS 5D mk II, to get a full spectrum camera with a full frame sensor and maybe also convert an EOS M.

I will do that when I get some spare time and access to a cleanroom.

I have the cameras and astronomik-windows already, but have not had any opportunity to do the conversion yet. With some luck it will happen later this year.

 

I believe that there are no disadvantages in using Canon cameras in this UV-photography-field.

 

One of the reasons Nikon has been dominant might be that some of their older camera-models had a rather weak UV-filtration.

Another that many that started with this was Nikonians. Also most dedicated UV-lenses in production are made for Nikon.

They are rather expensive and possibly out of reach if you are on a reasonably limited budget.

 

One big disadvantage with Nikon if you want to use cheap old classic accidental lenses with good UV-transmission is Nikons DSLR long back flange distance.

It is bigger than the distance often found on such old lenses, making it a bit difficult to reach infinity. On EOS a simple mechanical M42 to EOS adapter give you infinity.

Nikon cameras need adapters with optics, good enough to not destroy the optical quality, but without limiting the UV-transmission. This is naturally not a problem if you just focus on close ups. (Pun intended. :) )

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Nothing wrong with Canons. I Iike my Sony mirrorless, but I have a thing for tiny gadgets and I like how small it is. Also it has fantastic dynamic range, although I believe the Canons are also pretty good.
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Nothing wrong with Canons. I Iike my Sony mirrorless, but I have a thing for tiny gadgets and I like how small it is. Also it has fantastic dynamic range, although I believe the Canons are also pretty good.

 

nah Canon dynamic range is way behind the competition.

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Please justify this.

 

It looks to me like the Sony A7R III has dynamic range of 14.7, while the Canon EOS 5D Mark IV is 13.6?

 

Facts do not require justification :)

Landscape equates to dynamic range, sports to low light/ISO and Portrait to colour depth

 

The first time a Canon features in the top 50 for dynamic range is number 42 being the Canon 5D4.

DxOMark

 

All this said, in the real world, most people wouldn't notice the difference in printed or social media.

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Yep Canons are horrible cameras, they keep shooting out large metal spheres ruining the subject. Oh wait those are cannons.

 

I think why mirrorless are so common now is the shorter flange back allow you to use any lens. Most have live view with an EVF screen to focus in light where you can't normally see. Also common adapters will have built in helicoids, so you can focus to infinity and macro.

The camera brand doesn't matter much. Shoot with a camera that feels good in the hand and has a menu structure that will allow you to keep your hair.

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Ah, Canon vs Nikon vs A.N.Other. The age old discussion. Having had a few Canons made into multispectral, UV and/or monochrome, I have been very happy with what I have had done. For most of the time the Canons perform just fine for UV work. Where Nikon has the edge is noise at high ISO, or lack of it to be clear. I have a UV converted Nikon d810 and it'll happily run at ISO 10,000 with minimal noise. My EOS 5DSR will not do that. UV sensitivity Canon vs Nikon is very similar. So you pays your money, you takes your choice.

 

If I was starting again down this road, would I have ditched Canon and gone with Nikon? Probably not. I use Canon as I prefer it. I use Nikon when I have to. And if I want to use Nikon (or M42) glass I just mount it on my Canon.

 

As David says "Shoot with a camera that feels good in the hand and has a menu structure that will allow you to keep your hair".

 

Whatever you choose, do your home work with regards to IR leaks - cameras which do and do not leak, or have IR shutter monitors which contaminate the image.

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Interestingly enough, Canon is the top choice for those who have modified their cameras for astro-imaging, so it is rather surprising that in UV/IR photography they seem to be so "under represented"...

 

I wonder what caused the difference in brand representation between UV and Astro.

Could it be that the population of UV-photographers is so small that the brands originally used by the pioneers like Birna and Andrea still have a big influence?

Can a technical reason for a brand choice made long ago still affect the population of brands in such a small group?

 

Is the group of astro-photographers with modified DSLRs bigger and do they chose brand more for technical reasons than tradition?

Are those reasons also applicable for UV-photography?

It is clear the the quality of the optics is of uttermost importance for astro.

 

I did not chose Canon for a technical reason to be able to do UV-photography. I wasn't even sure it was possible with a Canon DSLR, due to rumors denying it.

I made my full bandwidth modification to be able to experiment with IR-photo using my normal Canon EF-lenses. Now I like the UV-part much more.

 

If costs isn't a limiting factor Nikon likely is the first choice. At least for the lens. I would love to have an UV-Nikkor 105mm on my Canon with a suitable adapter. :)

I have no idea what brand or model of camera would be optimal mainly for UV-photography.

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Certainly using a DSLR has its merits, regardless of whether its a Canon or a Nikon. I dont see any way to trigger a flash with my little A5000 so Im looking at getting a DSLR for just that purpose. I have a box load of Canon gear but will probably get a Nikon body purely based on the 105mm thats available. That said, I have a 1dx2 and a 5Ds for VIS, a 6D converted to 590nm and the Sony A5000. The D200 FS is a pain in the arse using anything other than a 25 or 25A filter for IR. Thing is, all my accessories are Canon so I will definitely explore that route.

 

As long as it has live view it shouldnt be an issue IMO. As I already have Canon gear for VIS, using an adapter wouldn't bother me but seeing as I don't have a FS body it may make more sense to get a Nikon rather than use a bunch of adapters as I definitely plan on getting a Nikon 105mm in the future. The flange distances mentioned by dabateman I haven't looked at so would need to be some more homework in that regard - thanks for the reminder.

 

In reality I don't think the bodies matter apart from the ability to be versatile with the older lenses and accessories we use in this genre.

 

Perhaps I should just re-convert the 6D to FS? Who knows :rolleyes:

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I wonder what caused the difference in brand representation between UV and Astro?

 

If I'm remembering correctly, the early Nikons tended to "eat the stars", as they say. Also Canon, as a manufacturer, was very much more supportive of providing info about their cameras so that third-party software could be written to support various imaging tasks such as those required for processing astro photos. Nikon was prone to secrecy. (Quite stupid on their part, IMHO.) So, early on, Canon became the go-to brand for Astro imaging. And what is set in motion tends to roll along the same way for quite some time w.r.t. camera brands. :D

 

I think that there was also some consideration about how to cool the camera body and Canons were easier to cool?

 

I am not knowledgeable enough about Astro needs to know where it all stands these days. Are mirrorless being used for Astro imaging? Do Nikons still eat stars? I read somewhere that some Sony A was a star eater.

 

ADDED: oh almost forgot. There was also something about long exposures which Canon could do and Nikon could not do. Now what was that about? Nikon had a bulb limit but Canon did not? Gotta look this one up.

 

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Can a technical reason for a brand choice made long ago still affect the population of brands in such a small group?

 

Seems to be the case in Astro imaging. I'm not sure about reflected UV photography.

 

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Could it be that the population of UV-photographers is so small that the brands originally used by the pioneers like Birna and Andrea still have a big influence?

 

For the record, Andrea entered the scene slightly later than the digital UV pioneers. :D

 

I'm not sure there is really an influence towards Nikons even though the pioneers did start with Nikons and even though two of the dedicated UV lenses have Nikon F-mount.

 

Bjørn Birna was always a Nikon shooter, working quite early on in film UV and then digital UV with one of the first Nikon digital D cameras. Klaus Schmitt used first a Nikon D70 (I think) and then changed to Panasonic Lumix G bodies. Vivek Iyer used Nikons, but I don't know what he currently uses. Those were the 3 people that I pestered with questions when first learning how to shoot reflected UV with my converted Nikon D200 because they were the only ones I found online back in 2007 who were showing reflected UV work. They were patient and kind, and I thank them once again.

 

Anyway, the next digital UV photographers did not all go for Nikons. Boon Tang used converted Olympuses. Alex Holochov liked converted Sonys. Many folks tried converted Lumix Gs because they were less expensive. (Birna and I still have Lumix Gs.) The only brand which seemed to be mostly unused by UV photographers was Canon. And I do not know why - possibly, as mentioned above, there was a misapprehension that the Canon sensor was not sensitive to UV. This, of course, has long since been disproved.

 

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I do think that noise supression and wide dynamic range is very useful for reflected UV photography which is quite "dark", very contrasty, and prone to noise. Given that Nikon was a leader for a long time in those two areas may explain some preferences for converted Nikons. But Sony soon caught up with that and so did Pentax. Panasonic, Olympus and Canon never did. But Sony was not chosen quite as often for conversions because it used lossy raw file compression in the early models and had an IR shutter monitor in later models. (So look carefully at which Sony models are best.) Pentax is almost never chosen for conversion and I don't know why. It is a great little cam, although perhaps a bit less easy to use for non-automatic, manual focus lenses.

 

The Fuji line -- I know absolutely nothing about whether it is useful for UV work when converted.

 

I'm getting ready to convert my Nikon Z7. I want to shoot it a bit longer unconverted, but will have it converted in time for spring buds and blossoms.

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I plan to have an Z6 converted to "full spectrum", but will wait for Andrea's experience in doing her Z7. Probably best if the camera is purchased in the US and modified there. I'll keep the stock Z6 and Z7 for ordinary photography, though.
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Certain Sony A still eat stars depending on the settings. Some models have been fixed I think? It is a firmware issue. I have not personally observed this behavior with my A7S yet, but have read that it can happen under some conditions. (Many nice Milky Way pics have been taken with the A7S as a quick google will show, so I’m not sure it’s a big problem for me.)
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This thread on Cloudynights provides some tests regarding star eater problem, it has just been updated with data on the Z6, which does not seem to show problems:

https://www.cloudyni...-4#entry9066778

 

Regarding Nikon bodies, it seems to vary from model to model, late professional models being best. That said, Nikon D5300 which currently is one of the most popular bodies for astrophotography is far from the best, but few seems to be bothered by it. There are some hacks available for some early bodies like my D5100 that turns the spacial filter off. I tried it, and it results in a pletora of hot pixels during long exposures, which would then require dark fram subtraction. Those star eater algorithms are there for some benefits too.

 

A quote from one page back in that thread by Mark Shelley:

"Here's my updated summary of behaviour of various Nikon models based on how the spatial filtering algorithm sets the threshold to determine which pixels are outliers.:

As a reminder there are 2 ways of setting this threshold:

(A ) Threshold is based on the maximum value of neighbouring pixels of the same colour as the pixel being examined

(B ) Threshold is based on the maximum value of neighbouring pixels, regardless of colour

 

The cameras that use a type-A criterion are the most destructive to tightly focused small stars.

The cameras that use a type-B criterion will cause little or no destruction to stars.

 

Examples of cameras that use a type-A criterion (the most destructive to stars) are:

Nikon D5300, D5500, D7500 plus all Sony mirrorless cameras

 

Examples of cameras that use a type-B criterion (almost no star destruction) are:

Nikon D7000, Nikon D800E, D810, D810A, D850."

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