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Photographing the Sun

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#1 philipus

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Posted 23 February 2018 - 03:54 PM

Hello everyone,

 

I'm curious about photographing the Sun with my film Hasselblad camera but I'm confused as to the various filters available. I've seen Thousand Oaks Optical's SolarLite and Silver-Black sheets, various glass filters and the Baader Astro-Solar sheets. My lens is a rather wide 350mm Tele-Tessar with a filter diameter of 96mm so I'm wondering if a sheet-type solution that fits over the front wouldn't be the best, but how well do such sheets work?

 

Thanks a lot in advance for your thoughts.

 

Philip 



#2 jimr2

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Posted 23 February 2018 - 04:28 PM

Phillip,
Yes, a sheet of the solar-film would probably work best on your camera since your lens is of such a wide diameter, as buying a filter in a metal or plastic cell to fit that lens would be somewhat more expensive than just buying a sheet of the material and either just attaching it to the front of the lens w/ a rubber-band, tape, etc., or perhaps making a filter holder yourself--there is at least one set of instructions for doing so out of cardboard on the web--think it's under Baader's solar filter website.
As to the type of filter material, as you know there are glass filters, and various "mylar"-coated filters. While the glass filters may be more resilient and hold up better over time, they are more expensive and produce an orange color to the sun, which most people think is "natural" but it actually isn't, as the sun, w/o our atmosphere to look through--especially when the sun is low in the morning or evening sky--is actually quite bright white. Some of the solar film filter material, like the Baader safety solar film material, produces a real "natural" color to the sun of near-white, rather than the orange-yellow of other filter materials. So it's basically up to you what you'd like in the way of color in your images of the sun as to which type of filter material to go with. If you do want to go with the glass/orange-colored sun filters, then Thousand Oakes is a reputable company to deal with, among others. They may also carry the "black" solar film material as well, but again that produces an orange color to the sun, and I believe isn't quite as good optically as the glass filters, and/or the Baader Safety solar film, which I think most everyone ranks the highest for optical quality for photography.
Hope this helps some?
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#3 photoracer18

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Posted 23 February 2018 - 04:35 PM

They work fine. If you have the ability to make a carrier that fits over your lens like a lens cap a sheet of Baader Solar Film is all you need to make one (or any other brand of solar film). Different brands and types of solar material show the Sun in different colors like white, yellow and blue. I used to work for Gary at Hands On Optics and we sold tons of that stuff by the square sheet (sad to say he retired last year). Should be places you can buy it. For something around 4" I suggest getting a 12"x12" sheet in case you need extras in case of a mistake or accident. That will give you 4 6x6 sheets.

See Thousand Oaks Optical. They also sell already mounted ones that clamp on the outside and also ones mounted in lens filter mounts.

I think the Baader film is available currently from High Point Scientific.


Edited by photoracer18, 23 February 2018 - 04:38 PM.

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#4 msl615

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Posted 23 February 2018 - 04:56 PM

Hi....once you solve the filter material and holder (the above messages have excellent answers),  the next challenge will be the exposure calculations. It has been over 30 yr since I had access to medium film format Hasselblads, and for the life of me I can't remember the exposure metering....whether through the lens or external. When viewing TTL, you will see a totally black field with a brilliant white (or orange depending on your filter) disk. Way easy to overexpose the sun disk. Hopefully, you will  have some sunspots to pick out on the surface. Will you be developing the film yourself? B&W, Color?  It may take some work to home in on an exposure that works for you, given the need to develop the film.

 

Good luck with the project, and maybe come back here to the forums with some images to share?

 

Mike


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#5 philipus

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Posted 24 February 2018 - 05:15 AM

Thank you very much for your replies, I appreciate them a lot.

 

I hadn't realised that the sun will look different depending on which of the various films I use. I am based in Europe so I'll try to order from teleskop-express or astroshop and see now that there are are a few solar films that come in ready-made circular contrapments that will probably fit over my lens so I'm leaning towards trying them first. 

 

Mike, thank you for bringing up the exposure part. On Flickr, I've seen examples with the Baader and Thousand Oaks films with shutter times of 1/80 or thereabouts with ISO 100. I would probably need to resort a bit to trial and error, including when it comes to film choice. I usually shoot Ektar, Provia and Portra and have them developed at a lab. But Provia wouldn't be my first choice because of the narrower exposure latitude. In fact I think I'll try Ektar first. I do my black and white myself and usually shoot Acros in the Hasselblad. I have a feeling one could get pretty cool results with black and white. I'll definitely post examples if (I have anything worthy to show...).

 

br
Philip

 

Phillip,
Yes, a sheet of the solar-film would probably work best on your camera since your lens is of such a wide diameter, as buying a filter in a metal or plastic cell to fit that lens would be somewhat more expensive than just buying a sheet of the material and either just attaching it to the front of the lens w/ a rubber-band, tape, etc., or perhaps making a filter holder yourself--there is at least one set of instructions for doing so out of cardboard on the web--think it's under Baader's solar filter website.
As to the type of filter material, as you know there are glass filters, and various "mylar"-coated filters. While the glass filters may be more resilient and hold up better over time, they are more expensive and produce an orange color to the sun, which most people think is "natural" but it actually isn't, as the sun, w/o our atmosphere to look through--especially when the sun is low in the morning or evening sky--is actually quite bright white. Some of the solar film filter material, like the Baader safety solar film material, produces a real "natural" color to the sun of near-white, rather than the orange-yellow of other filter materials. So it's basically up to you what you'd like in the way of color in your images of the sun as to which type of filter material to go with. If you do want to go with the glass/orange-colored sun filters, then Thousand Oakes is a reputable company to deal with, among others. They may also carry the "black" solar film material as well, but again that produces an orange color to the sun, and I believe isn't quite as good optically as the glass filters, and/or the Baader Safety solar film, which I think most everyone ranks the highest for optical quality for photography.
Hope this helps some?

 

 

They work fine. If you have the ability to make a carrier that fits over your lens like a lens cap a sheet of Baader Solar Film is all you need to make one (or any other brand of solar film). Different brands and types of solar material show the Sun in different colors like white, yellow and blue. I used to work for Gary at Hands On Optics and we sold tons of that stuff by the square sheet (sad to say he retired last year). Should be places you can buy it. For something around 4" I suggest getting a 12"x12" sheet in case you need extras in case of a mistake or accident. That will give you 4 6x6 sheets.

See Thousand Oaks Optical. They also sell already mounted ones that clamp on the outside and also ones mounted in lens filter mounts.

I think the Baader film is available currently from High Point Scientific.

 

 

Hi....once you solve the filter material and holder (the above messages have excellent answers),  the next challenge will be the exposure calculations. It has been over 30 yr since I had access to medium film format Hasselblads, and for the life of me I can't remember the exposure metering....whether through the lens or external. When viewing TTL, you will see a totally black field with a brilliant white (or orange depending on your filter) disk. Way easy to overexpose the sun disk. Hopefully, you will  have some sunspots to pick out on the surface. Will you be developing the film yourself? B&W, Color?  It may take some work to home in on an exposure that works for you, given the need to develop the film.

 

Good luck with the project, and maybe come back here to the forums with some images to share?

 

Mike



#6 philipus

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Posted 06 March 2018 - 05:10 PM

Well I got the Baader Astro Solar safety film, built my own filter and shot a few rolls the other day, one of which was Acros 100 which I developed in HC-110(E). This is probably the sharpest frame on that roll and I had much fun shooting. The effective focal length was 1400mm and aperture f/16. I'm not sure about the shutter speed but probably between 1/30 and 1/125.

 

On the larger version on Flickr it seems to my eyes it is possible to see some texture on the sun's surface. Is this imagination or just my poor film developing skills? According to spaceweather.com the sun is sunspotless since three days but I'm not sure I would have seen any with this setup.

 
26789167328_611f9e6d2d_b.jpg
Flickr
203FE

350/4 Tele-Tessar FE with 2XE+2x Mutar

Baader Astro Solar Safety Film
Fuji Neopan Acros 100 (HC-110(E) for about 7 mins at 21C)



#7 philipus

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Posted 07 March 2018 - 03:55 AM

Here's a slightly reprocessed version which I also cropped a bit. I'm a bit unsure about the processing actually. I've just followed my normal post-processing workflow which means dust spotting in Photoshop and then editing in Adobe Camera Raw. 

 

39958580004_f1350427c0_b.jpg


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#8 Great Attractor

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Posted 09 May 2018 - 08:45 AM

Good shot, Philip, but it seems that this texture is the film grain/some other form of noise underlined in post-processing. Actual solar granulation is somewhat finer and gradually diminishes toward the limb (as the granules are viewed at more oblique angle). You'd need very good seeing conditions to capture it well in a single frame.

 

Here's an image (shot with just 50 mm aperture) stacked from many frames (mono CCD camera) for comparison:

 

01df844318f75d9988879d0cc9cd026b.16536x1




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