Astrophotography with 4x5

[snaggs]

Has anybody tried this with their 4x5 camera? Any recommendations on film for 4x5 for Astrophotography?

Daniel.

 

[bwakel]

Daniel

As someone who uses a DSLR for astrophotography through an APM/TMB 130 f/7 super apo refractor, I can use film up to 6x7. I'm not aware of many scopes that will allow 4x5 and I've no idea how you'd attached a 4x5 camera to the scope (at least not for afocal astrophotgraphy). And then of course you're very limited on the film you can use. By far the best film I've found for astro work is Provia 400F (it'll be interesting to see how 400X compares) for its very low reciprocity failure. You could try Provia 100F but for deepsky work your exposures would be excessively long. As an example, using Provia 400F an exposure of M45 takes 45 to 90 minutes depending on the type of shot I'm taking. Considering that for best results it's best to shoot multiple shots and combine them in something like Images Plus, you'd run out of time using 100F. You'd probably be out all night trying to get a single image on 100F at 4x5.

Just my thoughts.

Barry

 

[wirehead]

This might come in handy, as you might have flatness problems.

I suspect a 4x5 would work for wide-angle astro but not the rest.

 

[Lee L]

I assumed you meant widefield shots with your camera and standard view camera lens. You might want to contact the person who did the color shots with the vacuum holder that wirehead mentions. His email address is on the web page and you could ask what he uses.

Choosing an astrophotography film is a matter of both reciprocity failure and what you want to record. There aren't many reviews of current films for astrophotography that I've seen. You want extended red sensitivity for certain nebulae around 656nm, which can be found in some data sheets. However, a peak there doesn't always mean the film registers red nebulae well. Then there's the problem of which films are available in Oz.

People seem also to be assuming you want color. Let us know a bit more about exactly what you want to try.

Do you have a polar mount of some kind for tracking the sky, and some way of guiding it?

Lee

BTW, John Glenn says thanks for leaving the light on.

 

[darinwc]

One of the problems you will have with 4x5 on a scope is that the opening of the focusing mount will restrict the field to only a potion of the film.

There are quite a few adapters for 4x5 holders to fit microscopes. I bet they would fit a telescope with only a minor adaptation. Sometimes they even some with graflok backs attached so if it doesnt work you still get the back.

 

[Wyno]

Hi Daniel,
there's a guy working at the Gordon TAFE where I work, who used to do astrophotography. He actually invented some techniques for photographing the sun. He used to teach very high level math at Deakin university but the pressure got to him and now he does the gardening at the Gordon. I think he used a large format camera and glass plates that he coated himself because he needes the flatness of glass, IIRC.
If you'd like I can ask him about it and perhaps get him to correspond directly with you.
Cheers
Mike

 

[DrPablo]

Snaggs, I've been doing some star trails shot with Fuji 64T on 4x5 if that's what you're getting at. It's very easy to do -- the hard part is making sure your picture is interestingly composed, as opposed to just star trails without a good overall composition.

There are quite a few adapters for 4x5 holders to fit microscopes.

Where? I've been looking for one.

 

[darinwc]

BTW thanks for the link for the vaccum film holder.. thats awesome!

for a microscope adapter, search ebay. here is an example: 290101999433
in the business & industrial, search for polaroid, microscope adapter, or microscope camera
in the camera section, search for polaroid microscope or microscope camera -digital
Some have electronically controlled shutters, and some have cool dial-set prontor shutters! (no aperture tho, and sometimes no threads)

the prices are random, and they are fairly heavy so shipping can be expensive.

 

[darinwc]

btw most of the adapters have lenses in them to widen the field of coverage to 4x5 size. So finding one in good condition may be important if you are actually going to use the adapter part. Some people just hack them for the backs. but with the expense of shipping its not really saving any money.

 

[snaggs]

Sorry, I didn't mean eye-piece astrophotograpy, I meant piggy back astrophotography. I have a LX90 with EQ wedge and thought I would try some widefield milky way shots.

The large lens element size on large format made me think that LF would be ideal for Astrophotography.

I was given 2 boxes of expired Kodak E100VS (2001, always refridgerated). I have read from some that its a good film for Astro (though maybe not as good as Provia 400F).

I'd like to try my hand at some star trails too. Following is the best newbie guide to Astrophotography I've found so far;

http://www.darkskyimages.com/gexpose.htm

I'll post some of my results to this thread. Now I've got the 4x5, Rolleiflex and FM3A, it won't be so boring doing long exposures as I'll have three camera's to play with

How did the 64T come out btw? I have some of that in 120 in the fridge. Could you post a sample?

Daniel.

 

[DrPablo]

Darwin -- thanks for the info. I have a lot of nice parasitology slides that might turn out great on slide film at huge enlargements. I'd like to find a way to attach a microscope to my actual view camera (this polaroid attachment in the E-bay auction looks sort of self-contained), because that way I could compose on the ground glass and get magnifications greater than just what the microscope objectives allow.

Daniel -- here is a recent shot of Orion on 64T. It was just for practice mainly because I'm waiting for a clear night with a new moon (in which I can get the heck away from Boston light pollution). This was a 10 minute exposure at f/8.

 

[darinwc]

There are complete microscopes that have the 4x5 adapter attached and have GG focusing. I would think that would be a better solution than cobbling together a view camera to a microscope. One thing that has been mentioned before is that it is better to use a smaller format film, shoot closer to 1:1, and then enlarge the resulting negative to suit.

note: this is just what I've heard and i have no experience with microphotography and such.

 

[darinwc]

heres an example of a microscope setup i was talking about. im not sure if this model has gg focusing, but I know some nikons do.. in fact they use a standard issue graflok.

Item number: 290099822407

 

[Sparky]

Sorry, I didn't mean eye-piece astrophotograpy, I meant piggy back astrophotography. I have a LX90 with EQ wedge and thought I would try some widefield milky way shots.

I'll post some of my results to this thread. Now I've got the 4x5, Rolleiflex and FM3A, it won't be so boring doing long exposures as I'll have three camera's to play with

I would just mount your 4x5 directly to a good mount. A Losmandy GM-8 comes to mind. The wind's going to be a bitch to you, though! You would definitely need to shield it really really well! I think the Rolleiflex might be a better bet.

Check out this guy's work - it was done on a 'blad. The wide field stuff is just stunning!

Dead Link Removed

After my research into the matter - it appeared that there was really no way around using an autoguider. The LX-90 would be a poor (flimsy) thing to piggyback onto.

 

[konakoa]

Hey folks, I wrote the page on the vacuum film holder. I also skulk here on APUG. When everything goes right, a 4x5 transparency of the night sky on the light box is really impressive to see.

I like Kodak E100G for my 4x5 astrophotography. I use my normal lenses and camera riding on top of a telescope mount. The telescope has no optical tube - it's just the mount with a electronic drive to track the stars. I shoot with my large format lenses wide open (f/5.6). Exposures aren't excessive -- for me, about fifteen to thirty minutes will do with 100 speed color transparency films before light pollution/skyglow becomes objectionable. Black and white negative films also work well for astrophotography, and benefit greatly from N+ development (an extra 20% or more to normal development times).

A guidescope helps with some camera formats. I have a small refractor with a crosshair eyepiece mounted next to the camera. I manually guide out any tracking errors of the telescope by noting if the stars 'move' in relation to the crosshairs in the guidescope eyepeice. It's not difficult - just a quick glance every so often to make sure everything's running smoothly.

I've found a guidescope isn't needed with my 35 for anything up to a 200mm lens. Medium format doesn't need it until I hit normal to slight telephoto lens range. For 4x5 it's pretty much a must for all lenses.

 

[Sparky]

Hey folks, I wrote the page on the vacuum film holder. I also skulk here on APUG. When everything goes right, a 4x5 transparency of the night sky on the light box is really impressive to see.

I like Kodak E100G for my 4x5 astrophotography. I use my normal lenses and camera riding on top of a telescope mount. The telescope has no optical tube - it's just the mount with a electronic drive to track the stars. I shoot with my large format lenses wide open (f/5.6). Exposures aren't excessive -- for me, about fifteen to thirty minutes will do with 100 speed color transparency films before light pollution/skyglow becomes objectionable. Black and white negative films also work well for astrophotography, and benefit greatly from N+ development (an extra 20% or more to normal development times).

A guidescope helps with some camera formats. I have a small refractor with a crosshair eyepiece mounted next to the camera. I manually guide out any tracking errors of the telescope by noting if the stars 'move' in relation to the crosshairs in the guidescope eyepeice. It's not difficult - just a quick glance every so often to make sure everything's running smoothly.

I've found a guidescope isn't needed with my 35 for anything up to a 200mm lens. Medium format doesn't need it until I hit normal to slight telephoto lens range. For 4x5 it's pretty much a must for all lenses.

Hi. Do you have anything you've shot online - it'd be really interesting to see!

 

[George]

---I like Kodak E100G for my 4x5 astrophotography. I use my normal lenses and camera riding on top of a telescope mount. The telescope has no optical tube - it's just the mount with a electronic drive to track the stars. I shoot with my large format lenses wide open (f/5.6). Exposures aren't excessive -- for me, about fifteen to thirty minutes will do with 100 speed color transparency films before light pollution/skyglow becomes objectionable. ---.

Danny, if you want to shoot point source lights (stars) the nominal aperture is not the thing to go after - only the actual physical opening. An f/5.6 lens can have a different size of its opening depending on the focal length. A plenty about it on google.

 

[konakoa]

George, I had to scratch my head a bit about "nominal aperture". Essentially, that means that my f/5.6 lens may or may not really be f/5.6, and that two lenses with the same aperture - but different focal lengths - won't transmit the same amount of light (like my 150mm f/5.6 and 300mm f/5.6).

Theoretically, that could throw off calculated exposures - like from my light meter. (That's why we all have personal EI's!) But then, a light meter also can't be used for stars. I arrived at my exposure times by trial and error. If the film was underexposed, I just reshot with a longer time. Nothing more complicated than that - really!

I've also found that more or less, for my kit I can use the same exposure times for both of my lenses. If I make a twenty minute exposure with my 150mm, I can switch to my 300mm, use the same exposure time, and get essentially the same density on the processed film. There is a slight difference between the two, but it's not huge.

Edit: By density, I mean the clear film base, not the number (that density) of stars.

 

[Sparky]

I can't say I really agree with that - if I'm understanding george correctly. Just because it's a point source - doesn't mean it's unaffected by aperture! (??) It's affected as much as anything else. Stopping down to f/8 will still require TWICE the exposure. But the question of 'how much exposure is enough' is a really tough one in astrophotography. The latitude is pretty great where a given (especially VISIBLE) star is concerned. I wouldn't bee TOO worried about 'accuracy of exposure', really. so- Danny - your observations make a lot of sense. Stars aren't immune from the laws of physics.

 

[Lee L]

There is a difference between aperture, i.e. the area of the lens opening in square mm, and focal ratio (or f-stop) that comes into play in astrophotography. With pinpoint sources such as stars, equal apertures (not equal f-stops), say a 400 mm f:6.3 lens and a 180 mm f:2.8 lens, will record the same number of stars (i.e. to the same magnitude) with equal exposure times. The lens with the faster f-ratio, the 180 f:2.8, will record more extended objects such as nebulae with equal length of exposure.

See Covington, Astrophotography for the Amateur, page 121 e.p, and Reeves, Wide-Field Astrophotograpy, section 4.5. This is not a violation of the laws of physics, it _is_ the law.

Lee

 

[konakoa]

I'll unashamedly admit it - I did have to google "nominal aperture". The vast majority of results I saw concerned rangefinder cameras, (namely Leicas) and how some of these folks were pretty concerned that their f/4 lenses were 'really' f/4.127.

I honestly love the technical minutia, yet I'm plenty happy just to get pleasing results with my astrophotography. If it looks good, I'm satisfied. Yes, when I think about it - a shot of Orion with my 35mm camera and 85mm lens has a finite number of stars on the film. With my 4x5 and 300mm lens, (roughly equivalent) the film is just stuffed with stars. "stuffed." That's a real technical term, ain't it.

 

[Sparky]

There is a difference between aperture, i.e. the area of the lens opening in square mm, and focal ratio (or f-stop) that comes into play in astrophotography. With pinpoint sources such as stars, equal apertures (not equal f-stops), say a 400 mm f:6.3 lens and a 180 mm f:2.8 lens, will record the same number of stars (i.e. to the same magnitude) with equal exposure times. The lens with the faster f-ratio, the 180 f:2.8, will record more extended objects such as nebulae with equal length of exposure.

See Covington, Astrophotography for the Amateur, page 121 e.p, and Reeves, Wide-Field Astrophotograpy, section 4.5. This is not a violation of the laws of physics, it _is_ the law.

Lee

IF this is true, Lee, then does it not stand to reason that, among the greater number of (fainter) objects that a larger aperture lens would record, that among these would be lower-magnitude and more distant stars?

 

[Sparky]

that would be amazing to see, danny! it'd be really cool if you could post something in the gallery if you can get a dense enough scan...! Or e-mail some of us if that's not feasible..!

 

[George]

LeeL has already answered and correctly. For pinpoint light sources the physical aperture is what decides the number of stars and their magnitude caught by the film, the actual f stop number is then decisive for the sky glow. Lee said it all with good web sites too.

 

[Sparky]

Sorry george - I really have to call you on this. You're talking about semantics. To MY understanding space is pretty much what we'd call 'an infinite and lightless vacuum'. In this case - what you call 'sky glow' is all the stars, nebulae and celestial bodies that are discernible with a high resolution system! So I guess it depends on how you use your words.