kaiserdave

6 minutes ago, bottletopburly said:

Did you know you can auto focus with a lens using APT .

That I did not know! I haven't really dug into APTs toolset properly yet! I have a slower 70 - 300mm tamron lens I could use that with, however I'm currently using an old pentax 200mm f/4 so no auto focus on that. 

I'll have to look into that and see what I can do with the tamron lens 👍

When you modded did you move the sensor in order to compensate for the missing glass? 

In theory when I did it I left the position alone and replaced the sensor as was knowing that I had a bit of "extra" focus on my lens. Also when I added the clip filter it brought the focus in my favour more. That's not to say I haven't reinstalled the sensor wonky of course! 

How did you check the level? Was it something obvious once you opened up the camera? 

Michael - Correct it uses live view and FWHM to determine the focus. 

I guess I could use bahtinov mask to give me a visual representation and try to focus either side of the sweet spot, take some exposures and see what I can make of it.

Thanks

Adam

On 01/12/2020 at 23:40, michael8554 said:

Hi Adam

I assume the APT Focus Tool uses the LiveView image, so should give good focus, even if the UHC Clip Filter isn't compensating perfectly for the removed LPF #1 ?

Also the UHC Filter spec says it removes out-of-band IR, so that shouldn't be a factor in the poor Red focus.

So that only leaves the lens.........

Michael

Hi all,

firstly i have modded my 1000d  - the lpf2 filter removal (no replacement).

I also have a uhc clip filter fitted. With this setup i am able to achieve normal focus without problem - I can achieve focus with the APT focus tool and back out before the lens hits the "stop" so no poblem there ( i think).

However when I take some test shots the stars look pretty terrible - which is particularly evident when an imaging session is stacked and the image separated into RGB mages.

The red chanel is rubbish whilst the green and blue are not bad (roughly stretched images for examples)

this was taken with the modded 1000d and a super takumar 200mm f4 lens.

I guess my question is what can i do to deal with this issue? 

Thanks! 

Adam