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Are Mirror Slap and Shutter Shock a Problem?

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#1 Gregory Gross

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Posted 17 April 2019 - 05:24 PM

I have recently been kicking around the thought of getting a classic SLR film camera (perhaps one depicted in classic Questar ads: Praktica FX, Pentacon, or Nikon F, for example) for doing some lunar photography with my Questar. We actually have a business close by that processes film, if you can believe it. But after reading a paper posted on Questar’s website entitled “Photography Using The Questar Telescope,” I see that mirror slap and shutter shock may be a problem (see pp. 3ff). Has anybody encountered this? Perhaps a more recent mirrorless digital camera would be a better investment?

#2 Optics Patent

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Posted 17 April 2019 - 05:52 PM

I don’t think there is any comparison between the images you can get from modern digital and film. Especially based on the images I see posted here.

This from the guy who bought an Arriflex 35mm movie camera to mount to a Questar Cinema Model.

#3 photoracer18

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Posted 17 April 2019 - 05:56 PM

You want a camera that has either mirror lock up or 2-10 second delay after the shutter is pressed so the mirror slap can dampen out. My first photos were done using an RV-6 and a Praktica astro-camera in junior high school in the early 60's. Also important to use a camera that doesn't go dead when the battery runs down. Nikon F2 or Pentax LX are good for that and both have interchangeable prism housing so you can put magnifier heads on them. What I used to do to eliminate the 2 issues was to hold a black cover over the tube for a few seconds after the shutter opened so the vibrations stopped. That was when I was doing long exposure and self guiding with a guidescope. Moon and such don't require that. Still as far as I am concerned the 2 greatest inventions in AP were autoguiding and digital imaging. I won't go back to film, even medium format for AP.

#4 RobertPettengill

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Posted 17 April 2019 - 06:19 PM

On a modern DSLR electronic first curtain shutter and mirror lock up will eliminate these problems. Film will give you inferior single exposures to a modern digital sensor. Lucky image stacking, an essential technique, for high quality lunar images requires digital.
A mirrorless body has significant advantages for astro images compared to a DSLR. No mirror slap, lighter, less back focus required, and often better digital focusing aids. If you use it with a fast camera lens for DSOs, then you can easily mount any brand of vintage lens. High quality manual focus SLR lenses are pennies on the dollar compared to new lenses with lots of features that don’t work for astro.
For planetary or detailed images of a small section of the moon, you can’t beat a small planetary video camera. I’ve had great success with the ZWO cameras. I can do almost as well with a Sony mirrorless, but the video cameras capture so many more frames for lucky image stacking that they are the winner unless you need a wider FOV

#5 davidmcgo

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Posted 17 April 2019 - 08:05 PM

And not all mirrorless digital cameras are free of shutter shock.  My beloved LUMIX GF1 has a physical shutter which can’t be disabled so I still get blurring from that.

 

So read reviews carefully.

 

Dave



#6 Gregory Gross

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Posted 17 April 2019 - 09:19 PM

Thanks everyone. My interest is driven by a pursuit not so much of image quality but rather of the experience of working with 35mm film as a medium. I have a bit of experience from my high school days a quarter-century ago (!), so I’m not coming at this completely cold. But it's been a long while since I've heard and felt the click of a proper shutter exposing film. I figure the moon is a pretty forgiving object to image, and I've found I really enjoy taking pictures of the moon.

Part of the charm is just acquiring an old camera to mess casually around with. Professionally I program (i.e., fight with) computers, so there is something to be said about the joy of a purely analog experience. And vintage cameras seem to be available for reasonable prices. For instance, there’s this mighty tempting Praktica FX going for $65 on eBay at the moment. $150-ish or so seems to be the high end for old Praktica FXs in good shape. As far as Nikon F cameras are concerned, those seem to run more at a premium, say $200 or so.

photoracer18: I did see the black card trick described in that Questar paper I mentioned. Interesting technique.

But the cheapskate in me doesn't like flushing money down the drain especially where costs could mount and mount (get camera, get film, take pictures, pay for film processing, trial and error and more error..., $$$). I've also been contemplating replacing my trooper of a point-and-shoot camera with a mirrorless digital camera (same convenience of a point-and-shoot but more flexible with a removable lens). A part of me questions why I should mess around with film and why I shouldn't just stick with digital. I hear all of you when you say that there is no comparison between film and digital.

#7 sachmo

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Posted 18 April 2019 - 11:38 AM

I would check around for a nice Olympus OM 1, good quality, light weight and compact with mirror lock up. There is also a lot of supporting accesories to be had that work well for astro.



#8 Optics Patent

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Posted 18 April 2019 - 12:01 PM

I've had an OM-1 since the late 70s in high school, and it not only has the mirror lock-up but interchangeable focusing screens including screen model 1-8 with a fine matte texture for astrophotography.  It's also appropriat5e because Questar sold a modified OM-1 in their catalog from 1973-87.  I believe that the only modification is the use of a more prominent lever instead of the smaller rotatable handle for the mirror lock-up.  I have the old one plus a modified one and can dig it out for a photo comparison if needed.

 

But... in my opinion shooting film for astrophotography is like commuting in a Model T.  Possibly a pleasurable anachronism, but of course you're giving up undisputed and massive advantages in performance (and safety and comfort in the commute example).  Even the ability to evaluate image exposure and other characteristics as you shoot is invaluable.



#9 davidmcgo

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Posted 18 April 2019 - 12:25 PM

Back in the day, I used to do lunar and planetary photography with a fork mounted Celestron 8.  The "hat trick" was always essential even with mirror lock up since at long focal lengths with eyepiece projection, just the vibration of the shutter curtain would kill the images.  Plus bad seeing, plus erratic tracking from the drive, and bad focus were all challenges.

 

Basically you held a black card in front of but not touching the telescope, opened and held open the camera shutter on bulb or time mode (cable release), let vibration die out, then remove the card and held away for what exposure you wanted, usually a few seconds, then slid it back, then closed the shutter.

 

Even with a 36 exposure roll of film, getting one or two halfway OK shots was average.  One nice thing about digital is not having to pay for bad shots in terms of film or development.

 

In terms of rough exposure guides, there was a book form Michael Covington that had graphs of effective f ratio and film speed and starting point exposure times for different planets or areas of the Moon (how close to terminator).  Highly recommended to track that down.

 

Dave


Edited by davidmcgo, 18 April 2019 - 12:26 PM.


#10 cbwerner

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Posted 19 April 2019 - 06:22 PM

The only reason to do film based astro photography at this point is the retro feel enjoyment of using a fine old mechanical instrument, so if that's what you're after, the Q makes perfect sense. If you go that route, as mentioned, mirror lock up helps, but you may find the hat trick necessary regardless. I did film astro photography years ago, first with a Pentax K1000, and later a Pentax LX, which had mirror lock-up and for which I had the special magnifying focusing attachments and special astro focusing screens. That made things a little easier, but not as easy as digital has become.

 

I'm actually in the process of de-computerizing my astro gear, going retro on everything except some limited imaging gear; I've decided I don't like a computer between me and my astronomy. I've also, by way of example, I've got an old Welta Weltur 6x6 folding camera that I'll play around with periodically when I'm in a retro mood. So I totally get the retro angle.

 

But with what it would cost me in time and frustration, I don't see me ever again putting a film camera on a telescope. YMMV.




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