Nikon lenses to CCD?

[garymck]

Hi,
I have some Nikon kit lenses that have no aperture selection ring that I would like to try some very wide field imaging using my ASI071MC Pro. Is there any adapter that can be used with this camera to enable aperture selection?

I have seen that there are adapters available that may be suitable, but am not sure of which one would be the correct one to get - I have no familiarity with them at all.

Would appreciate advice as to which one to get and/or if they are even suitable.

TIA
Gary

[Atmos]

If you set one of the function buttons on your anikon as a Preview, I think that is what it’s called, it sets the aperture blades while you’re looking through the view finder as a way of judging depth of field and the like.

If you hold the preview button down while the camera is on and remove the lens with the aperture blades set at what you want, the aperture remains set.
I’ve done this with my Sigma Art 85mm numerous times.

[pluto]

I'm sure you already know that ZWO make a Nikon lens adapter for their ASI cameras but of course it has no aperture control.

I have seen adapters for other lenses to other mounts which incorporate a mechanical iris allowing you to stop down an auto lens but nothing that would allow you to use Nikon lenses on an ASI camera.

There used to be a trick on Canon lenses where you could stop down the lens on a Canon body and then remove it from the body while holding the dof preview button and it would keep the lens at the aperture where you set it. Not sure if that works with Nikon lenses though.

However, if the Nikon kit lenses are much like the Canon kit lenses I probably wouldn't bother for astro stuff.
If it were my money I'd look for some nice older manual Nikon lenses rather than spend lots on adapters to use a kit lens.

My $0.02, hope it helps :)


EDIT Ah Colin got in before me! :D

[garymck]

Thanks guys,

I'll try the preview trick - I actually have a Nikon to m42 adapter, so I'll give it a try just as an experiment. I have read that the Nikon kit lenses are not bad if stopped down a bit, so will be worthwhile as an experiment. I f I decide I like it, I will hunt down an old manual Nikon lens. Any ideas which one to hunt for around the 135-200mm mark?

cheers
Gary

[Atmos]

I believe that some of the older 200mm F/4D lens’ were quite respectable.

[pluto]

I have an old Nikon 135/2.8 that is surprisingly sharp with virtually no coma. It also has a convenient little pull out hood built in.
Like this (http://www.ebay.com.au/itm/NIKON-MF-135mm-f-2-8-Nikkor-Q-Auto-SNr-256214/122558760949?epid=100091671&hash=item1c891247f5:g:XTEAAOSwwvZZS nKK) one.

[JA]

Hello Gary,

There are a number of possibilities. Which lenses do you have?

Best
JA

[garymck]

Hi JA
I have:
18-105 f3.5-5.6G ED
55-200 f4.5-5.6G ED
35mm f1.8G Prime

Cheers
Gary

[JA]

Well there you go. The perfect choice . The 18-105 gives up nothing really in sharpness to its prime brothers and will best or equal many. It is a very sharp lens, even wide open. The only thing you give up compared with primes is light gathering ability vide aperture. The 18-140 is also excellent. At the wide end there is slight coma, but this is reduced/eliminated at the tele end. The 18-105 is much better than the 55-200, see comparison image of MTF graphs cut & pasted below.

For what you've said you wanted to do,with your size CCD, I'd use what you have. Use your Nikon CCD adapter to mount the lens to your CCD AND if you are willing you use something to hold the iris open, by actuating the aperture lever on the back of your lens (since it is a G type lens) you're good to go. The aperture lever is not that delicate, but don't be too ham fisted.

Best
JA

[garymck]

Thanks JA,
I found a thread elsewhere about using a piece of cotton tied to the aperture lever to hold it open. I'll give it a whirl and see how I go.

cheers
Gary