9 replies to this topic

[johnmacd]

Hey Film Folks - Using Stellarium, I was able to see that I will have an excellent view of the upcoming Lunar Eclipse from my backyard (clouds permitting, of course).

 

I was wondering if anyone has any tips for getting some good shots.  This is will be my first time trying to get some images, so I want to make sure I'm set up for success...Here is my rig:

 

Celestron 8SE SCT (2000mm Focal Length; F/10)

Pentax K1000 camera body

f6.3 Focal reducer - if needed or suggested/recommended

 

My plan was to use the camera in prime focus, either directly to the scope back our using a nosepiece adapter into the star diagonal.  I can go either way...is one better than the other?  I imagine the nosepiece adapter might be better, because I can then easily slip the camera out, pop an eyepiece in and get some viewing done as well...but is there a preference for images 

 

Some suggestions for exposure time/ISO etc. would be helpful.  I came across this website - http://www.mreclipse...to/LEphoto.html - which has a table of suggested exposure times for a given F-value and film ISO.  I'm curious how accurate this might be...of course, I have seen multiple recommendations to bracket exposures, which I will absolutely do.  I'm just curious if the table on that website would be a good starting place.

 

I was thinking of using B&W film, about 200 - 400 ISO, but maybe for sharper pictures I should try ISO 100?  I'll be tracking with my telescope mount so I think I have flexibility with exposure times.  Any recommended brand of B&W film?  I'll use the B&W for the first phases, but then switch to color for the full eclipse (the red part).  Any suggestions for ISO and brand of film for color?

 

I also have a 2x teleconverter - I know those have a really bad reputation for stealing f-stop and on a telescope would probably make the moon way too big in the frame...but if I use the f6.3 focal reducer and then use the 2x teleconverter, is there some kind of advantage there?...or is that just making noise (i.e. reducing and then magnifying again), where I don't need it.  Maybe that is just silly talk...

 

I'm really excited about this opportunity and want to make the most of it...

 

Clear skies

 

John 

[TexasToast]

Use the reducer. It's needed to get a full frame shot. Very short exposures.

 

I'd suggest taking some shots a day or two before the eclipse to test your set up. Not sure how long film takes to process anymore so you may want to experiment sooner. 

 

It's been forever since I've used film but the ISO's sound right. 

 

Focus is pretty easy. Sharp edges. 

 

Note that there is typically a reddish shadow on the moon from Earths atmosphere. 

 

You might want to have a roll of color film handy.

 

Have fun and Clear Skies!

[johnmacd]

Use the reducer. It's needed to get a full frame shot. Very short exposures.

 

I'd suggest taking some shots a day or two before the eclipse to test your set up. Not sure how long film takes to process anymore so you may want to experiment sooner. 

 

It's been forever since I've used film but the ISO's sound right. 

 

Focus is pretty easy. Sharp edges. 

 

Note that there is typically a reddish shadow on the moon from Earths atmosphere. 

 

You might want to have a roll of color film handy.

 

Have fun and Clear Skies!

Excellent...thanks for the input.  Very helpful

 

The processing turnaround will be a challenge to getting in a practice run...I'll make sure to have lots of film handy.  Good thing a lunar eclipse is a relatively slow event.

 

Cheers

 

John

[SMigol]

Because your exposures will be at a long focal length, vibration will be a big thing.

 

Unfortunately, the K1000 does not have the ability to lock up the mirror.  

 

During the sunlit phases, the exposures will be short enough (remember, it's a sunny-16 target) that you may be able to freeze motion.

 

During the darkest times, you might want to use a hat trick with a black cloth on the scope objective instead.

 

Here's an example of a digital shot of an eclipse. https://flic.kr/p/93KUnv

 

This was ISO 100, F4.5, and .5 second.  Film will be comparable and would probably still show detail in the sunlit parts.

 

Your SCT may be operating at F10 or maybe F6.3 with the reducer, so you may have a full second or longer to expose the darkness of the moon.

 

Regarding the film choice, get something with good grain.  For the B & W, whatever you like - Acros is a favorite in 35mm.

For color, I like the Kodak choices.  Ektar will really pop the color and is very forgiving with over exposure.

 

Whatever you do, have fun!

Edited by SMigol, 06 May 2022 - 03:12 PM.

[SteveInNZ]

You probably want to have a look at Xavier's site. I think that answers most of your questions.

 

People don't appreciate how dim the eclipsed moon can be because we just adapt to it. The photo on the cover of Michael Covington's book is 5 seconds on Fujichrome 100 pushed to 200, taken with an 8" SCT @ f/10. He notes the blue tinge so it's not quite totality.

 

I'd definitely go for color. Otherwise, it's just a full moon shot made difficult for yourself. The color is what it's about.

I'd also bracket like mad and don't forget to account for reciprocity failure.

I'd probably opt for the reducer/flattener. It gives you a bit more light, shortening your exposures and bit more wiggle room in framing.

If the diagonal makes it easier to focus, use it.

I agree about the hat trick approach and the having fun bit.

 

Steve.

[johnmacd]

Thanks for the input so far...I do plan on emphasizing the "fun" part!!!

 

Cheers

[telesonic]

I would use the camera in prime focus, direct to scope. Adding the star diagonal to the path is just going to introduce more problems I think, as any rotation is going to be amplified... so keep it simple.

 

Now the question of the Focal Reducer, to be honest.... I'd try a couple of shots in each F/10 and also with the reducer on, because you never know. Obviously with the C8 in F/10, your exposures will be longer, so that is something to keep in mind. 

 

For film, I'd go with color.... Kodak Portra or Ektar maybe.... I only say to go with color film is because, well.... color. Lunar eclipses are really cool color wise, IMHO.

 

If you have a DSLR camera and t-adapter, you could also take a few shots with it, on the moon beforehand just for comparison - with the reducer and at F/10.

[Achernar]

Bracket like Hell. It may take 20 or 30 seconds to expose your film adequately. Also you might want to consider using your SCT at F/10, the moon will still fit in the field of view. Af F/10, 60 seconds might not be enough. So take plenty of shots at different exposure times. During the penumbral phase, you can use the shutter speed that gives you the right exposure for "cloudy bright conditions." At F/10 with 400 speed film, the starting point will be 1/250th of a second, but take frames at 1/500th, and 1/125th of a second. As the eclipse progressed towards totality, you'll need to increase exposure times. During totality, bracketing is important because the moon will be unevenly lit.

 

Focusing will be tough, I hope you have a Bhatinov mask or some other aid to achieving critical focus. Also, get your mount carefully polar aligned because if it isn't your photos will be trailed. Taking your time and getting it right will allow you to get photos like the one I got during the 2019 eclipse below, using a similar telescope to yours. Also, use the lunar rate if your mount has one, otherwise you will get blurred photos. I would use a dew heater strip dew cap and controller to keep your corrector plate clear. If you have vibration suppression pads for the tripod, use those too.

 

Since you're using a Pentax K-1000, there is no need for a battery, so you do not have to worry about the battery going dead and shutting you down. It's a good choice for long exposure work except there is no mirror lock. That can blur the photo but you can hold a black sheet of poster board in front of the telescope, open the shutter, then take away the cardboard. When it's time to end the exposure, replace it in front of the telescope then close the shutter. A long cable release is helpful here. I use a Nikon F3-HP which has a mirror lock, interchangeable focusing screens and viewfinders and does not need a battery when used on the T or time setting. A K-1000 is not as suited to astronomical photography, but still can be used successfully.

 

When you take the film to the lab for processing, ask them to leave the film uncut. Expose a frame on each roll to strong light so the edges can be seen so when you cut the film into strips for storage in protective sleeves you won't cut negatives in half. I would not have prints made initially, because many are likely to be too underexposed, or overexposed. Bracketing ensures you'll have some usable negatives. It's better to use color negative film than slide film, because overexposure up to a certain point can be compensated for in the printing or scanning process. Shoot two or three rolls of film to ensure you cover all the angles. Good luck.

 

Taras

Attached Thumbnails

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Edited by Achernar, 14 May 2022 - 05:40 PM.

[johnmacd]

Bracket like Hell. It may take 20 or 30 seconds to expose your film adequately. Also you might want to consider using your SCT at F/10, the moon will still fit in the field of view. Af F/10, 60 seconds might not be enough. So take plenty of shots at different exposure times. During the penumbral phase, you can use the shutter speed that gives you the right exposure for "cloudy bright conditions." At F/10 with 400 speed film, the starting point will be 1/250th of a second, but take frames at 1/500th, and 1/125th of a second. As the eclipse progressed towards totality, you'll need to increase exposure times. During totality, bracketing is important because the moon will be unevenly lit.

 

Focusing will be tough, I hope you have a Bhatinov mask or some other aid to achieving critical focus. Also, get your mount carefully polar aligned because if it isn't your photos will be trailed. Taking your time and getting it right will allow you to get photos like the one I got during the 2019 eclipse below, using a similar telescope to yours. Also, use the lunar rate if your mount has one, otherwise you will get blurred photos. I would use a dew heater strip dew cap and controller to keep your corrector plate clear. If you have vibration suppression pads for the tripod, use those too.

 

Since you're using a Pentax K-1000, there is no need for a battery, so you do not have to worry about the battery going dead and shutting you down. It's a good choice for long exposure work except there is no mirror lock. That can blur the photo but you can hold a black sheet of poster board in front of the telescope, open the shutter, then take away the cardboard. When it's time to end the exposure, replace it in front of the telescope then close the shutter. A long cable release is helpful here. I use a Nikon F3-HP which has a mirror lock, interchangeable focusing screens and viewfinders and does not need a battery when used on the T or time setting. A K-1000 is not as suited to astronomical photography, but still can be used successfully.

 

When you take the film to the lab for processing, ask them to leave the film uncut. Expose a frame on each roll to strong light so the edges can be seen so when you cut the film into strips for storage in protective sleeves you won't cut negatives in half. I would not have prints made initially, because many are likely to be too underexposed, or overexposed. Bracketing ensures you'll have some usable negatives. It's better to use color negative film than slide film, because overexposure up to a certain point can be compensated for in the printing or scanning process. Shoot two or three rolls of film to ensure you cover all the angles. Good luck.

 

Taras

Thanks a million for the tips.  On last Tuesday I did a practice run...B&W 400 ISO film.  The moon was bright.  I got some decent exposures, or at least I know the ballpark for a bright moon.  F/10 gave me a good field of view, and the shutter speed was quite fast - in the 1/500 range...but I'm not quite sure  ...here is the back story...

 

Tuesday I took a full roll of 36 (actually 37) exposures.  I took meticulous notes so that I could look at the best image and know exactly what I had done.  I took the film to get processed, and they did it the same day.  Processed the film and did a rough scan of the negatives.  I got the link for the images and downloaded them...only 26 images.

 

The next day, I picked up the negatives jumped in the car and went home...expecting to see only 26 frames, thinking that something messed up with my old K1000...nope there were 37 exposures.  So I don't know what happened, but to finish my experiment in time for the eclipse, I've had to order one of those cheap Kodak 35mm "scanner" things from Amazon.  I have low expectations for this thing, but at least I'll have all of the images to line up with my notes.  Attached is the best of the 26 images that were uploaded...For my first crack at it, I'm pretty happy.

 

I know that during the eclipse, things will get more challenging with the moon being dimmer, but I'm feeling good with my practice run and all the help you folks have provided.

 

Clear skies...and have fun for anyone looking at the eclipse tomorrow.

 

     

[telesonic]

Nice!

 

The test image you posted looks good @ F/10, and focus is good as well. Go for it!

 

On the subject of focusing masks, you may want to either buy or DIY a focus mask for your scope. And on that note, you can buy a commercially made Bahtinov, or you can start simple and make make a Hartmann (sp?) or Schiener mask with some standard art tools.....cardboard, a drawing compass, ruler and hobby knife. There are some variations, circular or triangular holes, spacing and size... etc.

 

I've made a few of each of the Hartmann and Scheiner for my C8 (and other scopes) several years ago from thin (or thick) plastic from school binder or notebook holders and dollar store things. They are rather simple, but work good enough. I have a few of them in my main gear tote, and they come in handy. They are also useful to collimate your secondary mirror on the C8.... but that is another topic entirely... just something to keep in mind.

 

 

Yep, and cover the front of the scope before the exposure.... the hat trick -as mentioned.

Most of all, have fun doing it - that is the main goal.

 

Best of luck!

Cheers,

T