350D modification to be or not to be

[obscura]

Thinking towards doing this myself and have read three sites on the subject - Honis etc. Intention is to replace the existing filter with a Baader BCF.

There is one area that appears a little obscure to me and that is the fitting of the new filter.

The guides infer running a silicone sealant - black? - around the new filter presumably light prevention. Can anyone advise as this apears to me as being messy with potential glue on the new filter. My experience with these sealants is yukky. Any particular sealant recommended if so.

Also, does the double sided stuck gasket come off easily enough and what happens if it don't? Not easy to make one as far as I can see.

Advice appreciated.

[Merlin66]

If you're going to use the modded camera for only astro work with a scope, then the filter doesn't have to be replaced.

You only really need it if you intend using standard camera lenses.

[Gina]

If you're going to use the modded camera for only astro work with a scope, then the filter doesn't have to be replaced.

You only really need it if you intend using standard camera lenses.

Couldn't you use an external filter anyway? Personally, I would not use yukky glue inside an expensive camera - too much chance of ruining it.

[George]

I'd be careful what sort of silicone you use near any photographic equipment as many of them use acetic acid as the curing agent which is corrosive and outgases. If its purely for astro use the filter does not need replacing.

[Merlin66]

Removing the filter changes the focus position outwards by 1mm.

This can be easily compensated in the telescope, but most standard camera lenses don't have the necessary adjustment to come to focus.

[obscura]

Astro only. I thought that the Baader cut IR and filtered the visible spectrum to 700nm give or take. Would I be OK then without the filter. Also wouldn't this mean that the sensor is wide open to the vagaries of the atmosphere?

I like the idea tho' of just removing the canon filter with holder in one go.

[Merlin66]

You can add (anywhere in the optical path) a UV-IR filter to block the excess IR (-I needed it for spectroscopy)

I never had any problems with my "bare" modded 350D in the four years I used it.

(I've just arranged for my 1000D to be modded "bare" - remove BOTH filters...for spectroscopy)

[George]

If its astro only I wouldn't bother replacing the filter.

I always used a CLS CCD filter which kept the sensor clean or you could use a clear glass filter if you don't need a LP filter.

I wouldn't personally go for the EOS clip filters BTW, if you ever move on to a dedicated CCD they will be of no use to you, much better to get the 2" screw in filters which will screw into any 2'' extension tubes.

[obscura]

This is sounding better and better.

A 2" filter in the extension tube? Can you advise a reasonably priced one.

Many thanks for this input Ken - trust you are ok and still taking the Ossie pick me up.

[Merlin66]

Just returned from Oz. The Eppalock Ridge is better than usual! ;-)

[George]

Astronomik CCD CLS Filter (IR blocked) 2''

Ive used this on the 300D, 350D, 1000D and my new QHY8......always been happy with it and the blue cast is easily removed in PS.

[obscura]

Many thanks George. I'll take a look at that and get down to modding my 350D. I see that one has done it in 45 mins but others in 3 hours plus. Guess that doesn't include the strip down again to see what's wrong.

So a few day sfor me but then what else would I be doing?

Thanks everyone, I'll let you know how it goes.

[George]

Best tip I ever heard of for doing the mods is do it in the bathroom

DIY cleanroom:

Run a hot shower until it creates lots of steam and fills the bathroom.

Turn off the shower and let the steam disperse.

Voila you will now have a clean room.....any dust mites will have been dragged out of the air by the condensing steam.

[Gina]

Best tip I ever heard of for doing the mods is do it in the bathroom

DIY cleanroom:

Run a hot shower until it creates lots of steam and fills the bathroom.

Turn off the shower and let the steam disperse.

Voila you will now have a clean room.....any dust mites will have been dragged out of the air by the condensing steam.

Thanks for that - very useful tip

[obscura]

Clean room had been in the back of my mind but I would never have thought in terms of a shower room/bathroom. The mrs could be a little happier me not hogging the dining room table. I'll take that on board.

Taken a cursory look at IR blockers and need to take cost into account. Any thoughts/knowledge of the Baader IR blocker? They are somewhat cheaper. Clip filters seem to be common for this purpose too but not so keen on them. The astronomik fit seems to be 48mm rather than 2". But this was a cursory look.

[George]

Whatever you buy make sure its the CCD version otherwise you will be blocking useful wavelengths

The way I look at it is a filter is for life that's why I give the clips a miss as they are only any use in a DSLR, 2'' are usable in any system.

[obscura]

OK, will do.

I was also going to ask about sensor cleaners but found previous blogs here recommending the rocket blower, pec pads and eclipse fluid. So I'll get those on order.

Thanks George