Look like no widefield for me - Silly problems

[swag72]

I really fancied a go at widefield, so last night set the camera on top of the scope and had a shot. What I discovered last night was that with the mod of my 1000D it will not achieve focus. I have confirmed that this morning with some daylight test shots - Just need a bit more, which I don't have.

Mmm, OK, so decided then I would try my 7D tonight, so planning ahead got the lens and clip filters ready. Well, on my 7D the clip in filters are all too loose and won't clip into the camera. I know that sounds silly, but as I have been using them on the 1000D I know how to put them in - On the 7D, they just flap about as though they are just a little too small. They don't sit and clip into place like on the 1000D.

So, it looks like no widefield ever for me

Just had another play with the 1000D and 7D side by side. There is no way I am putting the filter in wrong. It just sits in the 7D, doesn't clip onto anything and when you turn the camera over, it falls out. Damn damn.

[Psychobilly]

According to Astronomik they are compatible with the 7D...

Astronomik EOS Clip Filter System

What you might need to do is slightly open the gap between the main part of the filter and the thin curved piece.. I often have to do this when moving the filter between by different canon bodies...

If you have some L series lenses hanging around they may come to infinity focus... with a filter removed camera as they have a lot of extra travel beyond infinity compared to the standard EF or EF-S lenses... We had plenty of spare focus travel on George's filter removed cam at SGL6 with my 24-105 f4L

Peter...

[swag72]

I was using a 24-70/2.8 L last night, but just could not achieve focus at all. Maybe I'll try the 70-200/2.8 L - won't give me widefield as such, but may achieve focus.

I thought about moving the curve 'springs' but thought that I didn't want to break a £££'s filter. Back to the dining room table then Peter ...... Thanks!!

[Psychobilly]

Can you take a pic of the filter in place in the 7D before you start?

They shouldnt take much more than a tweak...

Which mod did you have done?

[swag72]

I've just given it a little tweak and it's holding in there at the moment. I was expecting a really big pull on the metal, but it seems OK for now.

Mod wise, I had the filter removal, no clear glass added.

[Psychobilly]

Glad the filters holding it normally doesnt take much as you found out... when you go to put it back in the 1000D you might have to put one side in first and then pop the other one in ratehr than trying to push it in square...

With the mod was it Whole filter removal or just the IR Part? Cant remeber what mod George had on his 1000D but we had plenty of extra travel.. if your only a bit down you can always stop the lens down a bit and hope the increased DOF will sort it out...

I got my mate to bring the lenses I was thinking of buying over for me to try on all my various modded canon bodies before I bought them...

[swag72]

None of my lens's were bought for astro stuff as I was pursuing an equally expensive photography hobby before I got the scope!

Not sure what the mod was, it was done my Andy at Astronomiser.

[Merlin66]

I bought a s/h Canon 1000D which I was assured had a "full spectrum mod - filter removed" I now think this is not the case as I can easily focus with normal lenses for daytime shots. The spectroscope shows a distinct cut-off at 700nm similar to the orginal Canon internal filter. The response to red is great!

May be we should consider swapping bodies?????

[ashworthacca]

That's a real shame Sara as I was really looking forward to seeing your widefield images.

Focussing was the reason I went for the filter replacement mod....perhaps you could contact Andy at Astronomiser to see if he could put a filter in?

[Psychobilly]

Just been testing the "vanilla" 500D against a filter replaced 1000D with a clip in filter and the 70-200 f4L . I used x10 zoomed in live view to focus on a pylon thats about 3 miles away - I used liveview as this is imaging sensor focussing rather than the viewfinder image or AF Chip focusing which can also be affected by filter changes/removal...

Both setups produced a sharp image onthe chip with the Infinity mark lined up with the focus mark on the lens body...

The Filter removed 350D had been left switched on so I am hvaing to charge the only battery I have for it .. I will then repeat the test with that body and the 70-200.. seeing as there is no live view on the 350D I will connect it to the netbook to review images whilst adjusting the focus setting on the lens......

BIAB...

Peter...

[Merlin66]

Peter,

Caution, the filter in the 350D is a different animal to those in the 450D and later.

The early cameras (including the 350D) had a very thick filter 2.8mm compared with the 0.8mm of the later designs.

I could NOT get my "full spectrum - filter removed" 300D to focus with standard camera lenses.

I'm still trying to understand the IR cut off and focusing of my 1000D "full spectrum modded"

[Psychobilly]

Ken I am just reporting facts based on the cameras I have at hand

At 70mm FL with th 70-200 f4L the difference in the focus position on the lens between the Vanila 500D and the Filter removed 350D is even greater...

The filter removed 350D needed to be stopped down to f5.6 to achieve focus.. it was almost there at f4...

as for you full spectrum 100D ... I guess when they were in there they didnt do the Full Hysterectomy... just a D&C...

[swag72]

Watching this with interest! Is there something I can do Merlin to test just what I have had done? I have emailed Andy at Astronomiser to see what he tells me was done.

[Psychobilly]

I guess it's the fact that the L series lenses that I have have the extra focus travel beyond the normal infinity stop means that I can still get vissible light infininty focus with the filter removed 350D...

There's less focus travel left than when we were using George's modified camera at SGL6...

[melsky]

Hi Sara

After my 550D was modded (filter removed) I tested my lenses to see if I could achieve infinity focus, all my canon lenses worked from the 15mm fisheye through to my 100-400L however when I tried my old Olympus Zuiko lenses (50mm 1.4 and 24mm) disaster they wouldn't quite get there. After the disappointment wore off I gave it some thought and tried again but this time with the clip filter in the camera and the Zuiko lenses now focus on infinity, hurrah. I also have a 600D non modded camera and I have noticed the clip filters are a much tighter fit than in the 550D.

Mel

[swag72]

Thanks for that Mel - I have realised that a little tweak is in order, so they at least fit in my 7D now and stay in there! Interesting about the clip filter enabling focus - Shouldn't really matter should it?

I've had a couple of nights practice now with the widefield, so I'll try the 1000D again and check that I was right and that I can't get focus.

[Merlin66]

The clip in filter is behind the lens, therefore "in the converging beam" - the focus will shift backwards ie longer by 1/3 of the filter thickness ie if the filter is 1.5mm thick the final focus will be 0.5mm further back.

HTH

[swag72]

Mmm, I will give it a go again tonight - Watch this space!!