Canon 450D mod questions

[pvaz]

So I got an old 450D laying around and I'm thinking about modding it.

Plan is to start with widefield photography with camera lenses then add an EQ mount and then a scope as I feel confortable with my results.

Questions

1) Which filter should I get to allow h-alpha?

I'm thinking about one of this but open to suggestions for a better one.

2) I have mild light pollution but it shows on long exposures. I'm thinking about getting a clip filter (this one). Can I attach an EF lens with it on, or is it only usable with a scope? Are there other options you'd recommend?

[Merlin66]

Paulo,

Good news is you just have to remove the colour correction/IR filter in the 450D.

The remaining front filter, the antiAlias/ dust shaker acts as a very good UV-IR blocker so there's no need for an additional filter.

With any of the clip in filters the EF camera lenses still work.

HTH

[Shibby]

When I modded mine, I used the Baader replacement filter. The reason is that I wanted AF to still work for daytime photography.

If you do this, just be careful with the glue when sticking the new one in - I ruined the first one

[Merlin66]

Lewis,

I was sure the AF still worked OK when only the colour correction filter was removed in the 450D.

I needed to fit an Astronomik MC (clear) EOS clip in filter to retain focus (with EF lenses) when I removed BOTH filters.....

In the older pre-350D there was only one filter element, and yes that did give problems!

[Shibby]

Are you sure?? According to Gary Honis (everyone's go-to DSLR modding guide), the AF doesn't work properly without the filter in place. Source: Canon Digital Rebel XSi (450D), XS (1000D), T1i (500D) , T2i (550D), T3 (1100D) Modification Instructions - Removal of IR Cut Filter for Astrophotography & Infrared Imaging - by Gary Honis

Also, I'm pretty sure it's an IR cut, not just a colour correction filter. Meaning for widefield you will ideally need to filter out the IR with another filter...

[Merlin66]

The thickness of the colour balance filter in the 450D is only 1mm, so the change in focus is about 0.3mm

Based on my spectroscopic measurements the remaining front antiAlias filter is the UV-IR blocking element. See graph in the other thread.

http://stargazerslounge.com/discussions-cameras/163579-finally-thinking-modding-eos1000d-anyone-had-done.html

[Shibby]

Ah ok, apologies, I stand corrected about the IR.

With respect to the change in focus, I seem to have been misled then? There are lots of modification services out there stating that the AF does not work with the filter removed and charging extra for filter replacement... Are they conning us? All the modification guides say the same, so I'm rather confused.

[pvaz]

Thanks guys. Seams I can try it out without the baader IR cut filter and save some cash.

Even if there is a small shift in focus I'll be using manual focus most of the time and I still got the 60D for daytime.

[Stephen]

Let us know how you get on, mine's arriving next week and I've got the urge to do the mod as well

[Merlin66]

All I can say is I used the 1000D with the colour filter removed and WLB for shots in and around the home trying to determine if they had infact removed the filter! (After I found the UV-IR was still being blocked I had the second filter removed - Astronomiser did a great job.)

My wife, I'm 100% sure would have commented if the AF was that far out to be noticable.

Maybe other users can advise.