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Shooting with a 4x5 - Hypered Tech Pan?

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#1 Acer

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Posted 01 December 2018 - 07:02 PM

Hello everyone.  

 

I am a long time photographer who is starting to get into Astrophotography.  I shoot with all types of cameras, from APS-C, Full Frame and Medium frame digital cameras, to 35mm and up to 8x10 film cameras, even do a little wet plate.

 

I am getting a EQ6-R Pro in, along with a 80mm scope which I plan to only use digital on, BUT I am thinking, maybe I can attach my 4x5 to the mount and shoot some film shots as well?

 

One of my all time favorite films to shoot is Kodak Technical Pan.  I use it on landscapes and just love the creamy, detailed photos I get out of it.  I also know back in the day, people used it for astrophotography.  I know they hyped the film with hydrogen to make it more sensitive.

 

 

Do any of you know how to hype the film?  I'm thinking of doing it just using some ziplock type bags.  The hydrogen itself is easy enough to get from my gas supplier (I have a full weld shop set up).  How long would I leave the film "Hyping" in the hydrogen for?

 

I would like to try out 4x5 astrophotography.  I'm sure it will be a little frustrating at first, but a lot of fun.  I'd probably shoot wide-field shots mostly.  



#2 petert913

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Posted 01 December 2018 - 07:20 PM

I can't wait to see some of  your results !!



#3 telesonic

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Posted 01 December 2018 - 07:46 PM

Acer,

 

Definitely look forward to seeing that also.

 

As far as the hypering goes, I've only read about it in books - I'm pretty new at this so I haven't actually done it. Hopefully someone can steer you in the right direction on that.

 

There are a couple of books that have information on it, Covington's "Astrophotography for the Amateur", and Wallis and Provin - "A manual of advanced celestial photography" has a pretty dedicated section on it. Robert Reeves "Wide-Field Astrophotography" is also a good one too. 

 

Those can be found on the used market, and I highly recommend them - there is a ton of useful info to be had in there. 

 

Temp



#4 TOMDEY

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Posted 01 December 2018 - 07:46 PM

I've done lots of 4x5 Gas-Hypered Tech Pan!

 

The camera was a nice Press Camera with a Cooke Triplet, I think it was F/4.5. Absolutely Magnificent for constellations. And Yes, you MUST H2-Hyper the film. I had my own roughing pump, pressure tank (modified pressure cooker), absolute pressure gauge, (0-60 PSI with ambient around 15) baking oven, with my own thermostatic control, etc., etc., no Life Insurance...

 

Are you saying that you CAN STILL GET Tech Pan sheet film?!

 

Guess what the toughest part was...

 

1) Keeping the film from expanding, contracting, puckering during exposure.
2) Squaring up the film to the focal plane of the lens.
3) Achieving critical focus.

 

Technique to address those three:

 

1) Sandwich the film twixt glass plates (stripped 4x5 film plates) with explosive lycopodium spores to prevent Newton's Rings
2) Laborious focus series, scrutinizing center and corners
3) Rebuild rails; add dial gauge to focus; focus with knife-edge on surrogate glass plate

 

What I'm saying... It's NOT easy.  Hope you get good results!

 

The results were Magnificent on constellations!  I did color, too...  Tom


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#5 Acer

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Posted 01 December 2018 - 08:07 PM

Thanks everyone!

 

 

I've done lots of 4x5 Gas-Hypered Tech Pan!

 

The camera was a nice Press Camera with a Cooke Triplet, I think it was F/4.5. Absolutely Magnificent for constellations. And Yes, you MUST H2-Hyper the film. I had my own roughing pump, pressure tank (modified pressure cooker), absolute pressure gauge, (0-60 PSI with ambient around 15) baking oven, with my own thermostatic control, etc., etc., no Life Insurance...

 

Are you saying that you CAN STILL GET Tech Pan sheet film?!

 

Guess what the toughest part was...

 

1) Keeping the film from expanding, contracting, puckering during exposure.
2) Squaring up the film to the focal plane of the lens.
3) Achieving critical focus.

 

Technique to address those three:

 

1) Sandwich the film twixt glass plates (stripped 4x5 film plates) with explosive lycopodium spores to prevent Newton's Rings
2) Laborious focus series, scrutinizing center and corners
3) Rebuild rails; add dial gauge to focus; focus with knife-edge on surrogate glass plate

 

What I'm saying... It's NOT easy.  Hope you get good results!

 

The results were Magnificent on constellations!  I did color, too...  Tom

After reading your reply, I did a little searching.  It looks like hypering Tech Pan is a little tedious.  I may still do it though.

 

You still buy Tech Pan, on Ebay anyway.  I buy it in 25-50 sheet boxes.  I've had luck with even 30+ year expired Tech Pan.  It is so slow that is really ages well, especially if it has been frozen/refrigerated.

 

Whenever I buy it, I take a sheet or two out and test it.  I've never had problems.

 

Here's a quick test shot from my last batch I bought.  Dev'd in Rodinal at 150:1 for 7 minutes, with gentle agitation every minute.

 

39440730441_7355a22e03_c.jpg4x5 - Technical Pan - Test 1 by Andrew Marjama, on Flickr


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#6 TOMDEY

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Posted 01 December 2018 - 08:20 PM

Acer, Good for You!

 

Now I'm chuckling... The Roughing Pump, and 4x5 enlargers... are forever buried in the foundation of our old house... the one that we Burned Down 12 years ago, and replaced with the nice one we live in now. The Press Camera, I gave away or sold off CHEAP. Most all of the other equipment is gone. I DO have some exquisite enlarger lenses... if you want...? First dibs to you. I think these were for the smaller enlarger. Pretty sure I left that in the basement, too?! But, I took the dichroic color head out and use it for colorimetry source now...

 

Ahhh... FILM... THOSE were the days!  Tom

 

Attached Thumbnails

  • 117 Rodagons 1.jpg
  • 118 Rodagons 2.jpg


#7 Todd N

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Posted 02 December 2018 - 01:14 AM

You can't use a plastic bag to hyper film. You will need a light tight vacuum chamber that can maintain pressure. A plastic bag would allow H2 out while letting in O2 and H2O that will counter the benefits of hypering. Robert Reeves' "Wide-field Astrophotography" is the book to get that details hypering Techpan. The other mentioned works: Advanced Manuel of Celestial Photography(Wallis & Provin) has a more theoretical approach to hypering without specifics to hypering TP and Astrophotography For The Amateur(Covington) touches upon hypered TP but is more so oriented to using off the shelf film.

 

Todd


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#8 Todd N

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Posted 02 December 2018 - 11:54 PM

Thanks everyone!

 

 


After reading your reply, I did a little searching.  It looks like hypering Tech Pan is a little tedious.  I may still do it though.

 

Hypering can be done more simply without heating the vacuum tank but hypering times are longer. I have been doing this in testing out various films for some time with pure H2 which is faster and probably necessary this way. I also buy pure nitrogen to purge the system. Both can be purchased in small 17 liter calibration tanks from Mesa Gas. There are some simple precautions to keep in mind when hypering with pure H2: Vent the H2 outside and don't use an electric vacuum pump to evacuate H2; There is a potential explosion danger there. With such a small tank volume, in and of itself won't prove to be an explosive danger in a normal size room but it could accumulate at the top of the ceiling. Here is a link to hypering TP for 8days with pure H2 at room temperature, second paragraph:

http://mais-ccd-spec...CCD Imaging.htm

 

My procedure:

Film in chamber, use electric vacuum pump to evacuate chamber

Fill chamber with nitrogen gas and then pump out the contents to get rid of residual other gases and water vapor

Fill chamber with H2 to 3PSI and let sit for however long is called for at room temp (68F)

When hypering completed, release H2 gas outside and then use a hand pump to evacuate as much H2 as possible

 fill with nitrogen again and use electric vacuum pump to evacuate.

 

The film can be kept this way for some days(possibly up to a month) until used. Higher temps shorten hypering times. For every 7C/12.6F higher in temperture will cut hypering times in half.

 

If you can't locate a Lumicon large format hypering chamber then you could possibly get something custom from Abbess (which I considered before but I was able to acquire a Lumicon chamber) and load the film in the chamber in a large format developing reel. The chamber needs to be light tight so get the top made out of metal if possible. You need a pressure gauge and to hook ups for the vacuum pump line and the gas:

http://abbess.com/vacuum/

 

 

Todd



#9 Acer

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Posted 03 December 2018 - 09:45 AM

Hypering can be done more simply without heating the vacuum tank but hypering times are longer. I have been doing this in testing out various films for some time with pure H2 which is faster and probably necessary this way. I also buy pure nitrogen to purge the system. Both can be purchased in small 17 liter calibration tanks from Mesa Gas. There are some simple precautions to keep in mind when hypering with pure H2: Vent the H2 outside and don't use an electric vacuum pump to evacuate H2; There is a potential explosion danger there. With such a small tank volume, in and of itself won't prove to be an explosive danger in a normal size room but it could accumulate at the top of the ceiling. Here is a link to hypering TP for 8days with pure H2 at room temperature, second paragraph:

http://mais-ccd-spec...CCD Imaging.htm

 

My procedure:

Film in chamber, use electric vacuum pump to evacuate chamber

Fill chamber with nitrogen gas and then pump out the contents to get rid of residual other gases and water vapor

Fill chamber with H2 to 3PSI and let sit for however long is called for at room temp (68F)

When hypering completed, release H2 gas outside and then use a hand pump to evacuate as much H2 as possible

 fill with nitrogen again and use electric vacuum pump to evacuate.

 

The film can be kept this way for some days(possibly up to a month) until used. Higher temps shorten hypering times. For every 7C/12.6F higher in temperture will cut hypering times in half.

 

If you can't locate a Lumicon large format hypering chamber then you could possibly get something custom from Abbess (which I considered before but I was able to acquire a Lumicon chamber) and load the film in the chamber in a large format developing reel. The chamber needs to be light tight so get the top made out of metal if possible. You need a pressure gauge and to hook ups for the vacuum pump line and the gas:

http://abbess.com/vacuum/

 

 

Todd

Thanks Todd for all the information.

 

It looks like I can get normal vacuum chambers for ~$!00 off ebay.  

 

I may go that route.  I have a Jobo developing tank for 4x5, so I could just load up that tank with sheet film and put the whole thing in the chamber.  That way I don't need to worry about light leaks as most of these vacuum chambers a clear lid.



#10 TxStars

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Posted 04 December 2018 - 12:35 AM

You want as little to no plastic in the hypering chamber..

Stainless film holders work the best...



#11 Achernar

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Posted 15 December 2018 - 10:09 PM

You can't use a plastic bag to hyper film. You will need a light tight vacuum chamber that can maintain pressure. A plastic bag would allow H2 out while letting in O2 and H2O that will counter the benefits of hypering. Robert Reeves' "Wide-field Astrophotography" is the book to get that details hypering Techpan. The other mentioned works: Advanced Manuel of Celestial Photography(Wallis & Provin) has a more theoretical approach to hypering without specifics to hypering TP and Astrophotography For The Amateur(Covington) touches upon hypered TP but is more so oriented to using off the shelf film.

 

Todd

Not only that, but hydrogen is not something you need to be breathing. Hypering the film is usually done with a mixture of 8 percent hydrogen and 92 percent nitrogen, and you will need a regulator, vacuum pump, pressure gauge, hoses as well as the gas cylinder itself. You can do it with hydrogen or nitrogen alone, but hydrogen floats upwards and indoors that could turn into very explosive pocket of hydrogen and oxygen. Therefore vent the chamber outside away from any ignition sources upon completion of hypering. Forming gas as it's called is a lot safer to work with and better than dry nitrogen gas alone. The apparatus must be air and light tight because the hypersensitization is done above atmospheric pressure and it must be heated as well if you need to do it as quickly as possible. Be aware many films do not respond well to hypering, Tech Pan is one that does better than most films that can be hypered. I never hypered film myself, but I do use the sort of gas cylinders and regulators you will need to have to do this, I have been a photographer and I also weld. You could get suitable 6061 aluminum stock, fittings and valves to make the chamber yourself and have someone who welds aluminum build it for you if you have no luck finding one elsewhere. Hypered film must be kept sealed and in cold storage, before and after exposure. After exposure, it should be developed as soon as possible.

 

Taras


Edited by Achernar, 15 December 2018 - 10:19 PM.


#12 Giorgos

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Posted 16 December 2018 - 10:56 AM

As long as you plan to shoot sheet film there is no reason to hunt around for hypering equipment (hard to find for sheet film).

There are alternative methods to hyper the film provided you will hyper, shoot and develop it as soon as possible.

You may try hypering with silver nitrate or with ammonia baths. These methods do not need elaborate and expensive equipment  but as I have already said you have to run not walk to the telescope. As long as you will shoot separate sheets of film and you are an experienced photographer it's not a big deal I guess. On the other hand I only know about them from the literature but haven't used them. Well why don't you try? In the worst case scenario you will spoil a few sheets of film!

Formula for hypersensitization of panchromatic plates from the 1931 book by Prof. King:

Distilled water 100 parts
Alcohol 25 parts
Strong ammonia 4 parts

Bathe each plate for 4 minutes, but do not rinse it before setting it to dry. The temperature of the solution should be from 62 to 68 F.

A good starting point for some experiments...


Edited by Giorgos, 16 December 2018 - 11:05 AM.


#13 Todd N

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Posted 16 December 2018 - 04:32 PM

As long as you plan to shoot sheet film there is no reason to hunt around for hypering equipment (hard to find for sheet film).

There are alternative methods to hyper the film provided you will hyper, shoot and develop it as soon as possible.

You may try hypering with silver nitrate or with ammonia baths. These methods do not need elaborate and expensive equipment  but as I have already said you have to run not walk to the telescope. As long as you will shoot separate sheets of film and you are an experienced photographer it's not a big deal I guess. On the other hand I only know about them from the literature but haven't used them. Well why don't you try? In the worst case scenario you will spoil a few sheets of film!

Formula for hypersensitization of panchromatic plates from the 1931 book by Prof. King:

Distilled water 100 parts
Alcohol 25 parts
Strong ammonia 4 parts

Bathe each plate for 4 minutes, but do not rinse it before setting it to dry. The temperature of the solution should be from 62 to 68 F.

A good starting point for some experiments...

 

I don't reccomend this. I've tried silver nitrate and ammonia hypering, not with techpan but other film to no avail. I have read ammonia hypering works well with TP(R.B. Minton) but in the films I've tried with ammonia alcohol hypering procedure damaged the film base leaving bizarre scratches/chemical etching; Probably not an issue with a glass plate substrate. Also, the alcohol so dried out the film that it was prone to static electrical discharge. I remember handling such a film in the dark and seeing bright static discharges in removing the reel from a development tank and another time rewinding it back into a cassette. Since the film is being washed in these processes, the film has to be used quickly and developed in a few hours. These washing methods are too precarious and not worth the trouble IMO. Gas hypering  with the proper equipment is quite the easier way to proceed.

 

Regards,

 

Todd



#14 TOMDEY

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Posted 20 December 2018 - 12:55 AM

I distinctly remember, that once I built and optimized my gas-hypering equipment and technique... it became quite easy, reliable, automatic and super-effective on Tech Pan, Ektachrome and similars. The handling in the dark takes practice. Anyone here will attest that pretend doing it, with already processed film and plates, lights on then off... is the way to get your technique down. Bummer when you flip on the lights and see your box of 50 unexposed glass plates... staring you in the face! Forgot to close the box.

 

I guess if we're doing film imagery here, already committed to imaging "the hard way" for the fun of it. For those who have not done home gas hypering before... well, it's not all that easy... never really was.  But it does work!    Tom



#15 TxStars

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Posted 20 December 2018 - 11:20 PM

Back in the day..(1986-95)  lol

A friend in my astro club was part owner of a pro photo lab.

We were able to use their high end densitometer to check our base fog levels when hypering our film and final results.

It made a big difference as we were able to precisely measure heat fog from using a heated chamber.

As well as mixed gas vs pure gas for hypering.

After all our testing we switched to only hypering at 70 F and using pure Nitrogen to dry and store and pure Hydrogen to hyper the films.


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#16 Giorgos

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Posted 08 January 2019 - 06:48 AM

I don't reccomend this. I've tried silver nitrate and ammonia hypering, not with techpan but other film to no avail. I have read ammonia hypering works well with TP(R.B. Minton) but in the films I've tried with ammonia alcohol hypering procedure damaged the film base leaving bizarre scratches/chemical etching; Probably not an issue with a glass plate substrate. Also, the alcohol so dried out the film that it was prone to static electrical discharge. I remember handling such a film in the dark and seeing bright static discharges in removing the reel from a development tank and another time rewinding it back into a cassette. Since the film is being washed in these processes, the film has to be used quickly and developed in a few hours. These washing methods are too precarious and not worth the trouble IMO. Gas hypering  with the proper equipment is quite the easier way to proceed.

 

Regards,

 

Todd

As a matter of fact using sheet film there is no winding in and out of cassettes and developing reels. Also if hypering doesnt work you have nothig to lose except a few dollars. On the other hand gas hypering of large format sheets has to do with gases (pure hydrogen is dangrous), high vacuum and hard to find obsolete equipment. As long as Acer is an experienced photographer there is no difficulty to develop the sheet film same day (night!).



#17 Todd N

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Posted 08 January 2019 - 09:31 AM

As a matter of fact using sheet film there is no winding in and out of cassettes and developing reels. Also if hypering doesnt work you have nothig to lose except a few dollars. On the other hand gas hypering of large format sheets has to do with gases (pure hydrogen is dangrous), high vacuum and hard to find obsolete equipment. As long as Acer is an experienced photographer there is no difficulty to develop the sheet film same day (night!).

 

The static discharges weren't limited to unwinding the film treated with ammonia/alcohol procedure.. The treated film will have to be removed stored which inevitably will come into contact with other surfaces that could cause such static discharges. I had dried treated film on a reel that I put in a development tank to temporarily store it and the reel touching the inside of the tank caused a discharge. The alcohol in this process really dries the film out. Such treatment with liquid solutions before imaging removes compounds that preserve the film and so, it has to be shot and developed in a few hours before it degrades according to the literature. It would be an unjustifiable waste to "experiment" in treating this ever more rarer film. It makes since to use tried and true methods to enhance the film and it's gas hypersensitization. See my post above #8: With some simple precautions pure hydrogen is not very dangerous. A 17/34L calibration tank of H2 isn't enough to cause an explosion if accidentally released all at once. A natural gas oven is more of a potential bomb. One doesn't have to use pure H2(which I use) and in fact most use a gas mixture with only 8% but that takes longer and the chamber  necessarily has to be heated. A low vacuum(-29.5psi) is standard for amateurs in this procedure and works fine.


Edited by Todd N, 08 January 2019 - 09:40 AM.



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