dSLR 300D - mirror slap

[Aenima]

I recently aquired a canon 300d body, and want to begin learning DSLR-Astrophotography.

This would be underway but for an immediate issue with mirror slap ruining every attempt at testing the camera and the process.

I really dont want to use the firmware 'hack' as every now and then something causes a very small loss of power which loses no data but will -kill my camera if this happens during the firmware update.,

But not knowing the whole dslr technique I was wondering if there is a remote shutter control device or camera control software that will enable the mirror to be fired first, then the shutter after a delay then another exposure etc. without having the shots ruined by judders from mirror slapping.

Its either that or physically sticking the mirror up with something or removing it - not really ideal.

Any thoughts, advice or suggestions would be appreciated.

Regards

Aenima

ps. The 300d hasnt got mirror lock without the firmware hack

[Cornelius Varley]

Without using the lockup hack it will be a problem. For long exposures you could try the "Top Hat" method. Place a piece of black card, or a top hat, in front of the lens. fire the shutter and then remove the card.

Peter

[Aenima]

Yes I've heard of that, though not surehow it works exactly. For example, do you hold the hat/card in front of the lens/camera or the lens/telescope? I have a newt. so this would be the opening of the ota rather than a lens, and the dslr is attached to the focuser so cant fit card in there. Would light pollution affect the 'black' of the card so when you move it the open shutter will detect this?

Sorry about the questions, i'm at a very early stage of learning dslr AP - only used webcams until now ;(

With bulb setting and a remote shuttter device can I somehow get the mirror to fire initially but the subsequent exposures just use the shutter each time?

Thank you for any help, much appreciated.

Regards

Aenima

ps. lets say i did the mirror lock firmware thing, hows it actually done and how safe is it for the camera? (its used)

[jgs001]

I'd suggest trying to shoot without worrying about mirror slap and see how you get on. I used to use the mirror lockup on my camera, but now I'm using APT to control my camera, I don't use any form of mirror lockup, and have not noticed any problems with mirror slap. Even on shorter exposures, but... that may depend on the firmness of the mounting.

[michael.h.f.wilkinson]

Holding a card in front of the scope is the easiest of the "top-hat" methods. Inserting it anywhere inside will introduce more shake than necessary.

[Aenima]

I'd suggest trying to shoot without worrying about mirror slap and see how you get on. I used to use the mirror lockup on my camera, but now I'm using APT to control my camera, I don't use any form of mirror lockup, and have not noticed any problems with mirror slap. Even on shorter exposures, but... that may depend on the firmness of the mounting.

Thanks John. (and Peter of course.)

I did want to proceed with regular astro photo without worrying about the lack of the MLU feature or hacks but it really does ruin my shots - I'm mainly attaching the camera to scope and then trying to get good focus on a star with bahtinov mask, or even get focus without the mask, but every shot the stars are zigzags from vibration- thinking in webcam mode I thought it was a shame you cant 'cut' the first few seconds from the picture but thats silly as the exposure is one long still shot (obvious I know but I have been using avi's for too long! )

So I havent got past trying to sharpen focus on a single point of light - so i'm not sure how to beging anything longer - those shakes will be in every exposure.

I keep looking at remote shutter cables - but dont know if the MLU option would be unavailabe for my camera.

Regards

Aenima

[jgs001]

If the option isn't in the firmware, then you'll need the hack. Or, use Peter's suggestion, and cover the aperture for a few seconds to allow any vibrations from the mirror slap to settle first. That way the wobbles happen whilst the sensor is not exposed to light.. then remove the cover.

[michael.h.f.wilkinson]

I am a bit confused by your last answer, Aenima . Are you using a remote cable release at all? My old Yashica FX3 (mechanical 35mm SLR) did not have mirror lock-up, but was fine, provided I used some cable release. The Contax RTS-II and RTS-III had lock-up, and I did use it, but I still needed to use a cable release. Pressing a button on the camera is gives WAY more shakes than the mirror slap. If you do not have a cable release, the self-timer can help. In that case it will take 10 s between you pressing a button on the camera, and the actual exposure.

[Aenima]

Okay, it is a tried and tested method after all

My mount is a little looser than the ideal AP set-up would demand, but just to capture mediocre images would be a next step up from where I am now.

Thanks for the help folks.

For targets like glob clusters etc. would 30sec exposure reveal much or would I need bulb setting? Or several of those shorter exposures?

Regards

Aenima

I really dont want to do the hack - (but options are dwindling.)

[Aenima]

I am a bit confused by your last answer, Aenima . Are you using a remote cable release at all? My old Yashica FX3 (mechanical 35mm SLR) did not have mirror lock-up, but was fine, provided I used some cable release. The Contax RTS-II and RTS-III had lock-up, and I did use it, but I still needed to use a cable release. Pressing a button on the camera is gives WAY more shakes than the mirror slap. If you do not have a cable release, the self-timer can help. In that case it will take 10 s between you pressing a button on the camera, and the actual exposure.

Actually yes, your right. Afraid to say its kinda in the post, but the timer was always used as a given - I dont really know which kind of remote to go for as some of the product descriptions are less than helpful as to whether the remote features MLock or it just triggers Mlock in an already MLU featured Camera.....

But thats right yes, only got the 300D body three days ago roughly and clear nights are rare. This is part of my question - whether a remote shutter device allows mirror slap to be avoided (without hack)

Thanks

Regards

Aenima

[jgs001]

A remote shutter release will allow you to trigger the shutter without touching the camera. It can only use the features in the camera, so if you do not have MLU, then you won't get MLU with the remote release.

[Aenima]

Thats what I thought. Hence ordered the basic type, held off getting anthing better remote control wise until that issue was resolved, thanks.

I'm going to assume, then, that the various eos software will not be able to trigger a feature that isnt in the cameras menu screen?

Same thing as the remote device, a lot of software packages say auto mirror control etc. but my camera just isnt compatible regardless of software designs?

Oh well. this hack looms. Dont like things that loom.

Many thanks folks,

Regards

Aenima

[Chris]

I'm also pretty sure the bulk of your zig zag star images are due to you pressing the button on the camera and once you've received you trigger release, any type of trigger release this issue will stop for you:) The only time I can think mirror slap would be a problem is if you want to take sub second exposures, its far more likely in my opinion that the 1000mm focal length of your Newt combined with an eq5 mount and you pressing the button by hand is causing quite a lot of vibrations which might take a while to dampen. If your still worried though just do the Unduchables hack which turns you 300D into a 10D:)

I did get a bit worried though before I realised you didn't have a trigger release:) I've just picked up a 300D body for around 50 quid on the bay and I'm planning to use it to practice modding as it would be low risk if it all goes pair shaped, I've fancied giving modding a go for a while, its a good excuse to buy more tools like a soldering iron:D. Because I already have a modded 350D if tests it show the mod is sucessful I'll pass it on to someone as a very cheap modded starter camera with a trigger release and all the things you need to get started:) anyway I digress, I've got my own questions to ask with regards to this so I'd better start my own thread:)

[Aenima]

Thanks starfox.

I was actually quite anxious to recieve the trigger cable initially, but thought after ten seconds delay - and stepping away - this would be similar to triggering from the cable.- does it really stay wobbling for longer than 10sec? I thought if the vibration happens during exposure, surely it will still be present in longer exposures as its already on the image? A shake after a millisecond of the chip being exposed would still register something wouldn't it, than after two milliseconds? - or whatever.....obviously i'm guessing here but this was roughly my line of thinking.

So there is still hope. This is the thing that worried me, still not being able to take any pictures - however amatuer they may be.

Things like auto-guiding can wait for now, I just want a couple of easy targets for simple quick images as an introduction to the whole thing, only got my scope last xmas so...(still getting the hang of planetary imaging. and love it - hoping to enjoy learning DSO just as much.)

Thanks to everyone posted above advice. Not gonna give up just yet.

Regards

Aenima

[Chris]

Right, I'm not sure you mentioned you were using a 10 second delay? yes I agree I would think 10 seconds would be enough to stop the vibes from manually presing the button unless your mounts made of jelly:D

Do the stars on your images trace out a zig zag which is uniformly bright? which might suggest a tracking issue, or is the zig zag bright in the middle and dim towards the oute regions of the zig zag which might suggest fast vibrations are the cause? in which case fast vibrations could be like you say mirror slap if your mount isn't that stable, or the wind catching the large surface area of you 200mm Newt might be causing vibrations as well? how long are your subs? periodic error in the motors might not be helping.

Can you post your zig zag star images up on this thread? it might help get to the bottom of this:)

Chris

[Aenima]

Right, I'm not sure you mentioned you were using a 10 second delay? yes I agree I would think 10 seconds would be enough to stop the vibes from manually presing the button unless your mounts made of jelly:D

Do the stars on your images trace out a zig zag which is uniformly bright? which might suggest a tracking issue, or is the zig zag bright in the middle and dim towards the oute regions of the zig zag which might suggest fast vibrations are the cause? in which case fast vibrations could be like you say mirror slap if your mount isn't that stable, or the wind catching the large surface area of you 200mm Newt might be causing vibrations as well?

Can you post your zig zag images it mught help with getting to the bottom of this:)

Chris

Yeah, if a pic would help i'd have to retake some as i deleted my CF as its only 512mg. But to describe the problem - I'm set up and attached via t2-ring. so want to try the bahtinov to get focus but the pattern (a 5sec exposure, after 10sec delay.) looks smeared, uniform brightness, by about x2 its size. And the mask removed after rough focus managed, stars look slightly oval and - not exactly zig-zags - with the same kind of smear-size, ie. the star is about 2 or 3x bigger with the extra bit extending only a mm or so from the actual point pretty uniform brightness, and not over exposed like circular but not really zigzag either, just looks like two stars joined - it can be worse but this is the average result.

Sorry, will get a picture soon if you wouldnt mind looking it over?

Many thanks.

Regards

Aenima

[dark knight]

Not giving up is a fantastic and inspiring attitude, things will improve I'm sure. A remote trigger/release cable will make a huge difference, I had similar problems with my Nikon D80 with 200pl on an eq5, I bought the remote release and it made a world of difference, suddenly my images were recognizable. I went for a programmable type which allowed for setting number of exposures, exposure length and a delay between exposures. This is very versatile and means once set up the camera does not need to be touched for anything up to 99 exposures of any exposure length up to 99hrs each . I can't help but think most of the problems are induced by having to touch the camera (pressing the button) something like this may help

http://www.ebay.co.uk/itm/Camera-LCD-Timer-Remote-Shutter-Release-C1-for-CANON-1000D-450D-400D-350D-300D-/350511794478?pt=UK_Photography_DigitalCamAccess_RL&hash=item519c21892e&_uhb=1#ht_4963wt_1163

You are also probably pushing your mount to it's limits with all that weight, so balancing it is all the more critical. Also critical is any dangling cables, it is amazing where any slight movement or vibration can emanate from and be transferred to your telescope, even the slightest of breeze can play havoc.

[Chris]

Don't mind looking at all next time you've got some pics:)

Right so you used 5 second exposures which gave elongated stars with uniform brightness, if you were using longer exposures and described this I would be convinced this was due to tracking error from bad polar alligmnent, but 5 seconds isn't really long enough to get significant tracking errors unless you weren't tracking at all at long focal length, or your tracking was really badly out at long focal length.

Try this next time your out, find a good spot to setup sheltered from the wind, grass is good for dampening vibrations. Don't extend your tripod legs at all keep it all low and all nuts done up nice and tight, work on getting the best polar allignment you can with you polar scope, EQ5's have a bit of backlash in the gearing so balance the scope so the gears are having to work a little bit to pull the counterweight up, not too much but a bit to keep the tension on the gears, if the scope is perfectly balanced with this basic motor drive system then the play in the gearing wobbles about a bit, and finally use you new trigger release:) hopefully this should help a little bit, I used to have a driven eq5 so I know a bit about them but it would be good if Quatermass chimed in as hes the master of the setup you have and might have more of an idea of whats going on? maybe you can Pm him if you're still having problems after your next go at it:)

[Aenima]

Thanks Carl.

I was wondering if my 300d could be made to trigger the mirror first, then controlling/triggering the exposure sensor after the mirror is held in the up position? It does not have the 'hack' for MLU so would this programmable cable allow this?

Thanks for the encouragment

Regards

Aenima

[Aenima]

Thanks again starfox

I'll follow your suggestion next session, the tripod legs only get extended if the levelling is off by a bit. And the general stability of the mount/tripod could use a little improvment, though after tightening whatever bolts I could it still needs something more by way of reinforcement.

Mark has given me some good advice and general pointers, but as for now my issues are clear and need things specific to sort them out, like timer cable and stuff that will take time to acquire..

Many thanks for the helpful posts, much appreciated.

Regards

Aenima

[Aenima]

Starfox, you mentioned tracking but I'm still waiting on a proper motor, ra drive. I'm sorry if I sounded like I was using tracking motors!

I understand tracking is essential and wont try anything serious without it, i'm just simply trying to practice getting focussed and using short exp. time to avoid drift. I am aware of the errors of drifting which i'm ignoring when assessing my images while sticking to judder problems being fixed. This is why I was worried about quick judders as opposed to startrails or smeared but correct star images in general.

I'm really sorry. Dont want to waste your time, (or test anyones patience ) I just forget that not everyone has followed my questions prior to these ones.

Apologies.

Aenima

[dark knight]

No it won't give something that your camera does not already have, but it will eliminate any user induced vibration caused by pressing the shutter release on the camera. I'm currently using my Canon 1000D and do not use any mirror lock up on that either although I control it from my pc using Backyard EOS (unfortunately at present this pc control software does not support your 300D). The priority is to minimize any user induced vibrations (physically pressing the shutter) as this will be your biggest nemesis, fortunately this is also the easiest to solve as remote timers/releases are readily available.

Maybe solving the issue with the power failing should be looked at first, solve that, then do the hack, then mirror lock up becomes a reality, either way I don't think the remote release would be wasted and would probably continue to be used until you maybe progress to pc and software shutter control. I am sure the answer is well within reach and there are plenty of people here who can help.

[Aenima]

PS. Many people were surprised to find out my planetary images were done using hand tracking, and i'm a little more proud of them for it.

Totally different story for DSLR AP.

Hand tracking would be worse even than no tracking. The most I can do is 1-5 seconds before trailing starts to interfere with monitoring other things like focus and camera shake, but even so - from what you've said, without tracking I cant properly assess mirror slap.

Back to the drawing board. I recieved the usb to camera connection lead but not yet the RA motor, so can I get back to you when it arrives?

Apologies again and thanks, much needed advice there.

Regards

Aenima

[Aenima]

Thanks again, Carl.

Thats encouraging news. Though if the programmable cable release wont control the mirror seperately to the shutter then maybe a more cheap and basic one will do....?

There are a lot of things recently been added to my wishlist, getting the 300D was great except now the ebay search starts again.

Many thanks to above posters,

Regards

Aenima

[Chris]

No worry's:) I'm sure when you get your RA motor and trigger release things will look a lot more rosey:)