Atik460 to Atik EFW2 connector

[gingergeek]

Hi all,

This may be a stupid question but after getting around to measuring my lens to sensor distance with digital calipers I reckon it is 57.5mm which is slightly more than desirable since I can't get a good focus on the CCD and lodestar via OAG at the same time. The only place I can possibly lose some distance is the adapter connector on the 460 (t2 to ?) to the EFW2 connector. I can't remember why I have it but it adds over 3mm to the total distance and a direct camera to EFW2 would be desirable.

Replacing this with an alternative connector with a lower distance effect is desirable if anyone can suggest one ...... once I persaude the current adapter to come off that is !!!!!

Regards

Gingergeek

[ollypenrice]

You should be able to get the EFW2 connected to the Atik camera with zero additional distance. They are intended to flush fit together, surely? Mine do.

From the Atik site; For example, the distance between any Atik camera and the wheel itself is 0mm, while still maintaining the possibility to rotating the camera to any desired position. Total extra backfocus needed will be only 22mm.

http://www.atik-came.../info/atik-efw2 Note that the FW has 54mm openings. This allows the big 11000 to work unvignetted. Atik do a choice of inserts for the FW, one with a large aperture for the 11000 and one for the other cameras, which is probably what's in the back of your wheel. You have to ask for the large aperture insert. The great thing about this insert system is that the inserts are rotatable so you can rotate the wheel and the camera independently. This can mean getting the wheel into a place where it allows longer before the meridian flip while still having the camera orientation you want.

Olly

[Starflyer]

I got one of these as I needed to add 3mm onto the spacing, maybe it'll take enough off for you?

[kirkster501]

The camera screws directly onto the camera side of the EFW2. No adapter necessary.

[ollypenrice]

The camera screws directly onto the camera side of the EFW2. No adapter necessary.

Indeed, so I'm wondering if the OP has something in there which could just be taken out?

Olly

[Gina]

Yes indeed, I too have the EFW2 and 260EX. The EFW2 comes with the zero offset T2 adapter so you just unscrew the 1.25" adapter from the camera leaving a T2 female thread which screws onto the FW with the camera face level with the FW face.

[gingergeek]

Hi guys,

Thank you for the confirmation, my memory is hazy so I think I added a 3mm screw-in spacer believing I required it but now my measurements with the digital calipers suggest otherwise. When I get home this evening I will try to remove the adapter from the atik460 and redo the measurements. These adapters are a real pain to remove once they are welded, I have the shoe polish trick and using the thinnest delrins but still they weld together

Regards

GG

[kirkster501]

Use two Allen keys or thin metal to insert into the holes on the adapter and remove that way

Sent from my iPhone using Tapatalk

[gingergeek]

Yay ! managed to get the 3mm adapter off the front of the Atik 460 but polite phrases do not come close to expressing what a struggle it was. Placed some delrin spacers in the image train at various places and the digital calipers say 41mm from the front of the FR to the back of EFW2, 0.3mm for the filter glass effect, 1.4 mm spacer between the wheel and the Atik 460 plus the 13mm backfocus gives 55.7mm. Hopefully I can test out the spacing tonight since I have a day off work for a change.

Regards

GG

[steppenwolf]

gives 55.7mm.

Sounds perfect - However, I suspect that you originally used that 3mm spacer to move the imaging camera outwards to match the focus position for the guide camera on the OVL OAG? Hope you can still move that guide camera inwards enough to get it in focus!

[gingergeek]

Steve,

I agree that the 3mm spacer at the end was probably used during our exchange to get the two sensors parfocal as possible coupled with my initial issues with the OAG and the slopping Focal Reducer.

I have measured the light path to the lodestar sensor at ~56mm so I will experiment tonight and if I can really nail this I will be as pleased punch.

Regards

GG

[steppenwolf]

With the imaging camera in 'perfect' focus, if the guide camera is a little out of focus, this will not necessarily be an impediment. There is an argument in favour of out of focus guide stars as it makes it easier for the guiding software to determine the centroid!