Just read the article written by John Jackson from DV.com.(HDV to Film: A Real-World Test)
Couple months ago, I just finished a documentary film by using this camera. I am satisfied with its setting and shooting quality. But I didn’t take the possibility of “HDV blowup to film” into consideration. In fact, I like the grain quality of film than video things. So the article of John impressed me, and the result of his practice did too. I put some clip of my documentary film here. You can see its “film-like” atmosphere.
John has described many important and basic points for attention. I rewrite here for keeping in my memory.
Video has a straight gamma curve. Film stocks often have a gamma curve shaped like a shallow S. Inexpensive cameras with "cine" gamma adjustments usually simulate this by tipping the straight video gamma.
Reducing the artificial sharpening (technically known as aperture correction) tones down harsh edges and avoids compression artifacts.
The clipping in HDV is really nasty, even worse than in DV. So an essential rule for shooting in HDV is don't overexpose! It's much better to be a stop under rather than a stop over while shooting. If necessary, you can stretch the contrast back out in post.
The slightly soft focus no matter what we used will be closer to film-like image.
Because HDV's MPEG-2 compression retains only one frame (the I-frame) every half-second or so and interpolates the others, native HDV editing must cope with a major challenge: Even a simple cut, unless executed at an existing I-frame, causes massive recompression and artifacting in the subsequent frames. I chose the CineForm codec, which is wavelet based and doesn't interpolate frames, to avoid this problem and gain some elbow room for the intense process of compositing and color-correcting.
Basic editing equipments: Windows XP CPU with a 3.2 GHz Intel Prescott HT processor, 2 GB of memory, and dual-200 GB SATA drives set up in a RAID-0 configuration for video storage.
Deinterlacing and conversion: 50i mode to 25p and 25p to 24p. 50i is better than 60i and true 24p mode in the situation.
Use smart" deinterlace in After Effects, which involves identifying those areas of a picture that have motion between the fields and those that don't, and selectively applying field blending only to the areas that have interfield motion. Another good option for smart deinterlacing is DV Filmmaker from DV Film in Austin, TX (www.dvfilm.com).
(Other deinterlace method in some low end Software half-down quality of AVI files. One is field duplication, the other is field blending. All the vertical resolution is instantly halved.)
……agreed that the blowup from Heavy Light looked very much like a blowup from 16 mm.
One of the very interesting discoveries I made was that the MPEG-2 artifacting in most scenes seemed very similar to film grain- very different from the obvious mosquito noise artifacting of DCT compression in DV footage.
Bonus: the smart deinterlacing method
Method 1: In the File menu, select Interpret Footage, and in the resulting dialog box, select the proper field order.. In the case of HDV footage, choose Upper Field First in the Separate Fields pulldown menu. Then check the Motion Detect box immediately below the Separate Fields pulldown, and click OK. Then, from the Effect menu, choose Video and apply the Reduce Interlace Flicker filter to the entire program. Set the Softness slider to 0.7-0.9. Do not exceed 1.0.
Method 2: In the Interpret Footage dialog, set Separate Fields to Off. The Motion Detect box will be disabled. Then, apply the Video/Reduce Interlace Flicker filter to the entire program. Set the Softness slider to 0.7-0.9. Do not exceed 1.0.
從HDV轉光學, 真的可以嗎?
John Jackson 在 DV.com寫了他的實驗, 跟我數月前用z1拍記錄片時的感覺很像(近日放上片段供參考), 但他更進一步地解釋跟測試, 看了轉35mm的結果, 據說是跟16mm轉35mm有得拼, 那真是太好了……這邊可以省下太多底片錢了.
把他文章中的重點, 跟自己知道的結合羅列於下, 以便參考:
在這個價位的HDV, 含CANON HL X1, JVC GY-HD100U及SONY Z1等機器, 在gamma的調整上, 並不是真的呈S曲線, 而是把原本video的gamma直接強化及銳化, 還是直線, 所以在拍攝時, 一定不能曝光過度, 寧可低半檔或一檔, 到後製再調色及光.
在拍攝時, 一點點的柔焦可以加強底片感.
由於真正記錄訊息的是I-frame, 所以在後製時, 適當的解碼器很重要, PC上可用AspectHD, Mac上可用LumiereHD. 如果用原始檔或其他不好的解碼器, 可能在時間及影像出現誤差及失真.
綜合說來, HDV是低預算劇情片很好的製作方式, 後期調光好的話, 真的可以跟16mm比拼的.
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