Full spectrum camera (not very) technical discussion
Hi all, I want to get into full spectrum photography in a couple years, but I have a hard time understanding how using a converted camera would differ from a normal one. I know you people like this stuff so I decided to enquire.
1 How is AF effected? I know phase detect focus is thrown off significantly when shooting in IR but is UV? Are they mutually exclusive for the focusing mechanism? What about contrast detect, I haven't found anything about that at all, I'd imagine it works fine but I dont know anything on the topic.
2 Why do people not always replace the hot mirror filter with clear glass other than for astro? In regular shooting lacking a piece of glass there is lacking protection and makes dust shake off ineffective, what is the upside?
To actually see the colors and appropriate exposure an EVF is crutial so when I get around it I'll be converting a MILC like a Sony A7, you feel free to prove me wrong though I'll take any excuse to use a DSLR. Also send me your favorite extended specrum pictures and tell me what you used for them, I love to see some pink trees.
- It depends. Some cameras do fine with conversion to a bare sensor and don't need anything adjusted, others work fine with replacement cover glass with the right depth, others some lenses work and others don't, period. This is why there are preferred/popular models for IR and lists of which lenses work etc.
- Doing it yourself and not replacing the glass is free. It's not preferred for any reason other than cheap DIY!
- Pink foliage is not going to come from infrared. You can get red using filters, but pink will be something you have to do in post.
- re: DSLR, you don't need an EVF, you do need liveview. Any DSLR with liveview would be easy enough to use for IR.
@ahoyhere has great answers. I concur. The other thing about focusing with IR is that IR light focuses at a different point than visible, so you'll get different results if you're IR/visible or a mix. I don't find this a huge issue unless you're on a DSLR without live view (avoid for the best experience). Also, I just stop down and do landscapes and it's forgiving.
And how cool that you're thinking of infrared! It's very fun. I have yet to do just UV. That would be really neat. Here's some favs of IR stuff I've done.
Mamiya ZD with IR cut filter removed and IR chrome filter
Water tower by Snappiness, on Flickr
Tomato by Snappiness, on Flickr
Sony F828 with magnet hack to remove IR cut filter + 720nm filter
Gorman Falls by Snappiness, on Flickr
Earl Scott Pond by Snappiness, on Flickr
Pentax K-01 full spectrum converted + IR chrome filter
IMGP9636 by Snappiness, on Flickr
Roads Diverge 4x5 crop by Snappiness, on Flickr
I also had a Sony A100 DSLR that was infrared converted at one point, and the Kolari Pocket (modified Canon point and shoot). Fun stuff!
