can we upgrade ios 8.1 to ios8.2 instead of 8.3 in ipad3

No. If you upgrade, it will always be to the latest version available.

For a limited time you can install 8.2. ( When Apple releases a new version of ios, they allow downloading both versions for a few days. ) It been a few days do not delay.

Here is a list of what version of ios are available for each iDevice.

http://api.ineal.me/tss/status

somewhere in one of these threads you should be able to figure out the how to.

For a limited time Apple will allow you to downgrade to the previous release. Hurry do not wait. This period lasts for at most a week.

See brownox second post here:
https://discussions.apple.com/thread/6545455
and
http://www.gottabemobile.com/2014/09/17/downgrade-ios-8-to-ios-7/

see what versions are allowed:
http://api.ineal.me/tss/status

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see the post by arizonacat and others in this thread.

https://discussions.apple.com/thread/5337442?tstart=0

arizonacat points out these sites:

• Provides easy access to Apple firmware files.
  http://www.ipswdownloader.com/
  
• How to install the ios software. The install will erase your exiting data. Backup your existing data.
  http://osxdaily.com/2010/11/23/how-to-use-ipsw-files/

If I had known the latest update would make my rear camera pictures blurry I would not have updated! Now I can only take clear pictures with the front camera on my iphone 5 I just got 😟

I doubt that has anything to do with the update. I suggest you take it to Apple Store and ask them to check it out.