Telescoping Problems (1 Viewer)

Hi ALL
I have been an avid reader of your blog for many months and as a bird watcher I have been taking photos with my Nikon D-90 and Sigma 150-500mm .As always you are never near enough for a good picture.So ,I decided to purchase a SW 80ED and try to follow your excellent examples.
However not being a very technical person at photography I have hit a snag when I first tried to use the set up in the back garden.As suggested by your good selves my set up is as follows- D-90/60mm extension tubes/Max DSLR/SW80.The extension tubes are the cheap non electronic versions and I also have a Kenko 1.4 teleconverter also waiting to be used once I have mastered the technique.

My question to any one out there is how do I obtain the aperture setting with the above set up as I can only adjust the speed setting.
I have set the camera to full manual and the ASA TO 800. It would appear that with on my Nikon camera that the light meter does not work so how can I adjust the f stop, or is it fixed at f7.5. I am a little lost so any help would be most appreciated.
Thanks Alan

Hi Alan

Welcome and all that good stuff.

Your setup is not the problem, it is the correct way from your description.

The f/ stop of the scope is a set value, f/7.5 in your case (600mm / 80mm = 7.5). You can't change that, it is a given. It is not like a camera lens that provides an adjustable "iris diaphragm" to vary the f/ stop.

I believe that on Nikon DSLR's you will not have metering at apertures larger than f/5.6 or f/8. You have to eyeball the histogram and make adjustments by varying the shutter speed accordingly.

On Nikon you should, however, have focus confirm, whereas on Canon it is the other way around - we have metering but no focus confirm.

Hope this helps.

Best regards

Jaco

As suggested the aperture is fixed at 7.5 and the camera can't read that due to no contacts. You could use a dandelion chip glued into the Max DSLR. These can usually be programmed with information like f number etc. This should then give you some metering capabilities. Hopefully some Nikon users can help in this department.

Paul.

Paul Corfield said:

As suggested the aperture is fixed at 7.5 and the camera can't read that due to no contacts. You could use a dandelion chip glued into the Max DSLR. These can usually be programmed with information like f number etc. This should then give you some metering capabilities. Hopefully some Nikon users can help in this department.

Paul.

Click to expand...

This is correct. Adding a Dandelion chip to the adapter will enable all metering modes. You just have to program the chip to say it's an 600mm f/7.5 lens and the camera will be quite happy.

Thanks all for your comments .I have tried the suggestions but its a bit hit and miss at the same time as trying to catch a bird in flight.Can you purchase these dandelion chips already attached to an adapter or are the all do it yourself?????

ORDY1 said:

Thanks all for your comments .I have tried the suggestions but its a bit hit and miss at the same time as trying to catch a bird in flight.Can you purchase these dandelion chips already attached to an adapter or are the all do it yourself?????

Click to expand...

many sell them already glued to an adapter. I got one to glue myself, but it was a PITA, so I got me a glued one ;-)

ORDY1 said:

Thanks all for your comments .I have tried the suggestions but its a bit hit and miss at the same time as trying to catch a bird in flight.Can you purchase these dandelion chips already attached to an adapter or are the all do it yourself?????

Click to expand...

They tend to be in T-mount adapters or m42 adapters. Probably better to just get the chip and glue it into the Max dslr unless you want to swap to a T-mount. Example of one here on ebay.

http://www.ebay.co.uk/itm/AF-Chip-D...745?pt=LH_DefaultDomain_0&hash=item41649922c1

Paul.

It's not really difficult to glue the chip on - I've done several - but it does have to be placed precisely. In some cases the mount has to be filed down or built up a little. Some of the sellers provide a simple jig that helps get the position right. Just use a slow drying glue like 30-minute epoxy so you have plenty of time to make adjustments!