Firmware upgrade for Canon EOS 400D?

[ninja2]

Hello IIS , my very first post....

I found an article on the ASSA website about a firmware 'hack' for a Canon 300D, that added ISO 3200 and provided 'mirror-lock' (I've no idea what that is or does, but the author seemed very excited so it must be good :)).

I'm just starting to work out what equipment I will need to do 'astro-photography' as a newbie. It just so happens I have a much neglected Canon 400D Rebel XTi in one of my 'archive drawers' and the idea of using that really appeals.

I searched the internet and of course there's plenty of stuff on a similar firmware 'hack' for the 400D. My question for IIS people: has anyone done this reasonably recently and successfully, and if so what is best method / source?

many thanks

[ZeroID]

Hi Chris,:welcome: to IIS.
To be honest you don't need ISO 3200 for astrophotography. 400 -> 1600 max is the norm. Above that and the gain produces too much noise from the sensor. I run my 450D at either 1600 or 800.
400D will work just fine as it is. The only downside to that model is it does not have Liveview which makes focussing so much easier with either Back Yard EOS or AstroPhotgraphy Tools so you can use your PC. The 450D is then lowest model with that very useful feature.

Nonetheless the 400D will still connect to a PC with BYE or APT and you can control the shutter and other functions. You can start by just using a remote cable and the inbuilt 30 second exposure setting for deep sky exposures.

I'd be saving the $$ for a decent mount because without that long exposures are not really an option. Video of planets or the moon is feasible. Does the 400D have a movie mode ?

[sharkbite]

folks - i have used the "400plus" hacked firmware -

Like ninja2 said - ISO3200 is very noisy.
(that camera ain't great at even ISO1600)

there is no live view or movie mode.

Hacking the cam in my view has limited application for astro -

400plus has an intervalometer - you can use this for timelapse stuff.
(here's something i did a few years back)
https://www.youtube.com/watch?v=mQSybwliwu0

[ZeroID]

Yeah but at least you can cut your teeth on the process at ISO 800 and plan for a better DSLR later. Got to start somewhere.. I kicked off with my old KM 7D, only 6 mb sensor but it was successful enough to make me rebuild my whole telescope and buy a mount. And more cameras. And other stuff .......:question:

Dammit !! So THAT's how it started, now I know where all the money went.. :lol:

[ninja2]

Thanks for the big welcome .... :)

Your answers are a big help. A few Q's if I may:



OK thanks, but now I'm curious: If, down the track, I buy a higher quality camera would there be less sensor noise and so ISO > 1600 is sometimes useful?



I have Backyard EOS although I haven't played with it much yet. Do BYE or APT work with Backyard EOS? And where do I get them?



Unfortunately not. According to this comparison table (https://en.wikipedia.org/wiki/Comparison_of_Canon_EOS_digital_cam eras) on Wikipedia shows 400D just missed out on Liveview and video mode (as pointed out by sharkbite). darn!

[bugeater]

BYE is Backyard EOS, so you've already got that. APT is Astrophotography tool, which I think does basically the same thing as BYE (I've not used either to any great extent).

As to the camera - I think really what you eventually want is a lower noise camera and more recent/expensive cameras are better for this I think. This is why they can got to higher ISOs before noise becomes an issue. Being able to go to high ISOs in and of itself isn't important.

(note I'm a beginner at all this too, so take my advice with a grain of salt ;))

[ZeroID]

You're on the money there Marty. BYE and APT are similar applications and do the same thing. I'd happily use APT but I've already paid for BYE and I'm happy with that too. They are not hard to use once you understand some of the terminology.

The next 'best' Canon model in the newer offerings for astro is the 1100D (or it was) as it is a very low noise sensor. Same sensor size (12.2m) as the 450D but newer technology. Nonetheless it is still better to capture real photons at lower ISO's than push the ISO up to using gain to simulate photons. It will still introduce more noise to some minor extent. There is a lot of info put together by more erudite people who have tested and documented the results on various cameras, sensors and their settings.

I got my 450D cheap because it had a small problem but astro use doesn't need that function. My next purchase I hope, will be an 1100D, not because it will be faster but because it will have less noise at 800 ISO.

What you are looking to do is get the best signal to noise (S/N) ratio possible. Most of what you are imaging is invisible to the human eye and only marginally brighter than pitch black so that is the critical factor. The better that S/N ratio the more object photons (Signal)you will capture compared to empty space photons and pixel noise. Again this is documented by a number of experimenters.

In the meantime use anything you have to learn and experiment. My first were with what is now my guidescope, an 80mm f5 Achro using my old Konica Minolta 7D (6m) on a modified EQ2 mount ( with a brick hanging underneath to steady it!!:eyepop: ). With a CLS (ClearSky) filter I got quite acceptable Lagoon and Trifid images in my early attempts.

That is when you start learning and start spendi.... err growing your knowledge and expertise. I've still got a long long way to go and I'm enjoying the journey at every step.

[ninja2]

Thanks Brent and Marty ... lot's of great clues there to help me 'grow my knowledge and expertise' ... at a low spend rate :). See how I go !

One more Q: is ISO 800 commonly used for most astro-photography? Are there situations where lower ISO's are better.

[bugeater]

I'm not sure the ISO is greatly relevant, since it doesn't mean you collect any more information/signal. Taking a photo at a lower ISO might look darker, but you can just adjust later in software to achieve the same effect as the higher ISO - the amount of data is the same for the same exposure. At least this seems to be the case once you get past the really low ISO figures. ISO might be slightly more relevant if you are shooting JPEGs though due to lower bit depth than RAW.

[ZeroID]

You need some 'ISO' to amplify enough photons to get an image to work on. If you imaged at 100 ISO eg you would probably need about 20 hours of stacked images to get enough photons to work with. By going to 800 ISO eg you amplify the signal the photon creates at the sensor and it takes 1 or 2 hours to get enough. The crunch comes in balancing the two. Too much gain = too much noise. As I mentioned before there are some people who have experimented seriously with various cameras and sensors to figure out the best option for each. Newer cameras have better sensors with lower noise, you can therefore push them to higher ISOs without too much noise being included.
My SONY SLT A77v has an excellent sensor, I have pushed ISO to 6400 but it's sweet spot seems to be 1600, maybe 2400. For older cameras like 400D and my 450D 800-1600 is about it. 800 is generally better.

[Merlin66]

Brent et al,
The ISO settings never impact on the number of photons received by the chip.
At ISO 100 and ISO 32000 the chip receives the same number of photons.
All the ISO does (in most cases) is the act as a multiplier to give a brighter image based on the photons received.
I find in spectroscopy, that ISO 200 to 400 is all you need,
Additional "gain" can be achieved with the imaging software.
Just my 2c

[ninja2]

wow guys, great explanations. I reckon I've got it now: it's all about finding sweet spot balance between gain/ISO and noise, for the task at hand. And sensor noise depends on camera quality.
cheers & thanks

but wait, seeing as I'm on a roll ! :-) ... what is 'mirror-lock' all about when astro-imaging?

[ZeroID]

As I basically said Ken ... 'amplify enough photons'
Worded differently but it's the same message.

[ZeroID]

Mirror lock is to prevent the DSLR Mirror movements causing vibrations at the camera. It locks the flip mirror up out of the way.
My SONY uses an SLT screen with an Electronic Viewfinder, no mirror so it's not necessary.
On the Canon 450D I add a 2 sec delay for exposure to start to allow any vibrations to settle from the mirror flipping up to expose the sensor.
BYE has this in the planning area. APT as well I guess, haven't looked.
Once I've established focus I could lock the mirror up between exposures so no further vibrations are created. Would eliminate the delay.

[ninja2]

OK got it, thanks Brent